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<title>Apple II History</title>
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<h2>Apple II History<hr></h2>
Compiled and written by Steven Weyhrich<br>
© Copyright 1991, Zonker Software<br>
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(PART 1 -- PRE-APPLE HISTORY)
[v1.1 :: 12 Dec 91]
INTRODUCTION
This project began as a description of how the Apple II evolved into
a IIGS, and some of the standards that emerged along the way. It has grown
into a history of Apple Computer, with an emphasis on the place of the
Apple II in that history. It has been gleaned from a variety of magazine
articles and books that I have collected over the years, supplemented by
information supplied by individuals who were "there" when it happened. I
have tried not to spend much time on information that has been often
repeated, but rather on the less known stories that led to the Apple II as
we know it (and love it) today. Along the way I hope to present some
interesting technical trivia, some thoughts about what the Apple II could
have been, and what the Apple II still can be. The Apple II has been
described as the computer that refuses to die. This story tells a little
bit of why that is true.
If you are a new Apple II owner in 1991 and use any 8-bit Apple II
software at all, you may feel bewildered by the seemingly nonsensical way
in which certain things are laid out. AppleWorks asks which "slot" your
printer is in. If you want to use the 80 column screen in Applesoft BASIC
you must type an odd command, "PR#3". If you want to write PROGRAMS for
Applesoft, you may have some of those ridiculous PEEKs and POKEs to contend
with. The disk layout (which type is supposed to go into which slot) seems
to be in some random order! And then there is the alphabet soup of disk
systems: DOS 3.3, CP/M, Pascal, ProDOS, and GS/OS (if you have a IIGS). If
you use 16-bit software EXCLUSIVELY, you will probably see none of this;
however, even the most diehard GS user of the "latest and greatest" 16-bit
programs will eventually need to use an 8-bit program. If you can tolerate
a history lesson and would like to know "the rest of the story," I will try
to make sense of it all.
I think one of the Apple II's greatest strengths is the attention
they have paid over the years to be backward compatible. That means that a
IIGS "power system" manufactured in 1991, with 8 meg of memory, a hand-held
optical scanner, CD-ROM drive, and 150 meg of hard disk storage can still
run an Integer BASIC program written in 1977, probably without ANY
modification! In the world of microcomputers, where technology continues
to advance monthly, and old programs may or may not run on the new models,
that consistency is amazing to me. Consider the quantum leap in complexity
and function between the original 4K Apple ][ and the ROM 03 IIGS; the
amount of firmware (built-in programs) in the IIGS is larger than the
entire RAM SPACE in a fully expanded original Apple ][!
This strength of the Apple II could also be considered a weakness,
because it presents a major difficulty in making design improvements that
keep up with the advances in computer technology between 1976 and the
present, and yet maintain that compatibility with the past. Other early
computer makers found it easy to design improvements that created a better
machine, but they did so at the expense of their existing user base
(Commodore comes to mind, with the PET, Vic 20, Commodore 64, and lastly
the Amiga, all completely incompatible). However, this attention to detail
is just one of the things that has made the Apple II the long-lived
computer that it is.
In examining the development of the Apple II, we will take a look at
some pre-Apple microcomputer history, the Apple I, and the formation of
Apple Computers, Inc., with some sideroads into ways in which early users
overcame the limits of their systems. We will follow through with the
development of the Apple IIe, IIc, and IIGS, and lastly make some comments
on the current state of affairs at Apple Inc. regarding the Apple II.
PRE-APPLE HISTORY
Let's begin our adventure in history. I've designed a special
interface card that plugs into slot 7 on an Apple II. It contains an item
its inventor called a "Flux Capacitor" (something about the being able to
modify flux and flow of time). The card derives its power from a
self-contained generator called "Mr. Fusion" (another item I dug out of the
wreckage from a train/auto accident in California a couple of years ago).
Connected to the card via a specially shielded line, Mr. Fusion runs on
trash (and is, therefore, the ultimate computer peripheral, if you recall
the old principal of "garbage in, garbage out"). Let's put a few issues of
PC MAGAZINE into Mr. Fusion, and switch on the Flux Capacitor.
(Incidentally, for this to work, it needs an Apple II equipped with a
specially modified Zip chip running at 88 MHz). Boot the disk and set the
time circuits for 1975. Ready? Set? Go! ** CRACKADOOM ** !!
Did you make it all right? (Just don't touch anything -- you don't
want to disrupt the space-time continuum, you know!) Now, since the first
Apple II wasn't released until 1977, what are we doing back in 1975? Well,
to understand how the Apple II came about, it helps to know the environment
that produced it. In 1975, the microcomputer industry was still very much
in its infancy. There were few "home computers" that you can choose from,
and their capabilities were very much limited. The first microprocessor
chip, the 4-bit 4004, had been released by Intel back in 1971. The first
video game, Pong, was created by Nolan Bushnell of Atari in 1972. Also in
1972, Intel had gone a step further in microprocessor development and
released the 8-bit 8008, and then the 8080 in 1973. The year 1974 saw
Scelbi Computer Consulting sell what some consider to be the first
commercially built microcomputer, the Scelbi 8-H, based on Intel's 8008
chip. However, it had limited distribution and due to the designer's
health problems it didn't go very far. The first home-built computer, the
Mark 8, was released that same year. The Mark 8 used the Intel 8080 chip,
but had no power supply, monitor, keyboard, or case, and only a few
hobbyists ever finished their kits. Overall, the microchip had yet to make
much of an impact on the general public beyond the introduction of the
hand-held calculator.
With the start of 1975 came a significant event in microcomputer
history. If you will consider the early microprocessors of the years 1971
through 1974 as a time of germination and "pregnancy" of ideas and various
hardware designs, January of 1975 saw the "labor and delivery" of a special
package. The birth announcement was splashed on the front cover of a
hacker's magazine, Popular Electronics. The baby's parents, MITS, Inc.,
named it "Altair 8800"; it measured 18-inches deep by 17 inches wide by 7
inches high, and it weighed in at a massive 256 bytes (that's one fourth of
a "K"). Called the "World's First Minicomputer Kit to Rival Commercial
Models," the Altair 8800 used the Intel 8080 chip, and sold for $395 (or
$498 fully assembled). MITS hoped that they would get about four hundred
orders for clones of this baby, trickling in over the months that the
two-part article was printed. This would supply the money MITS needed to
buy the parts to send to people ordering the kits (one common way those
days of "bootstrapping" a small electronics business). This "trickle" of
orders would also give MITS time to establish a proper assembly line for
packaging the kits. However, they misjudged the burning desire of Popular
Electronic's readers to build and operate their own computer. MITS
received four hundred orders in ONE AFTERNOON, and in three weeks it had
taken in $250,000.<1>
The Popular Electronics article was a bit exuberant in the way the
Altair 8800 was described. They called it "a full-blown computer that can
hold its own against sophisticated minicomputers now on the market... The
Altair 8800 is not a 'demonstrator' or souped-up calculator... [it] is a
complete system." The article had an insert that lists some possible
applications for the computer, stating that "the Altair 8800 is so
powerful, in fact, that many of these applications can be performed
simultaneously." Among the possible uses listed are an automated control
for a ham station, a digital clock with time zone conversion, an autopilot
for planes and boats, navigation computer, a brain for a robot, a
pattern-recognition device, and a printed matter-to-Braille converter for
the blind.<2> Many of these things will be possible with microcomputers by
1991, but even by then few people will have the hardware add-ons to make
some of these applications possible. Also, despite the power that micros
will have in that year, the ability to carry out more than one of these
applications "simultaneously" will not be not practical or in some cases
even possible. The exaggeration by the authors of the Popular Electronics
article can perhaps be excused by their excitement in being able to offer a
computer that ANYONE can own and use. All this was promised from a
computer that came "complete" with only 256 bytes of memory (expandable if
you can afford it) and no keyboard, monitor, or storage device.
The IMSAI 8080 (an Altair clone) also came out in 1975 and did fairly
well in the hobbyist market. Another popular early computer, the Sol,
would not be released until the following year. Other computers released
in 1975 that enjoyed limited success were the Altair 680 (also from MITS,
Inc., based on the Motorola 6800 processor), the Jupiter II (Wavemate),
M6800 (Southwest Technical Products), and the JOLT (Microcomputer
Associates), all kits.<3> The entire microcomputer market was still very
much a hobbyist market, best suited for those who enjoyed assembling a
computer from a kit. After you assembled your computer, you either had to
write your own programs (from assembly language) or enter a program someone
else wrote. If you could afford the extra memory and the cost of buying a
BASIC interpreter, you might have been able to write some small programs
that ran in that language instead of having to figure out 8080 assembly
language. If you were lucky (or rich) you had 16K of memory, possibly
more; if you were REALLY lucky you owned (or could borrow) a surplus paper
tape reader to avoid typing in manually your friend's checkbook balancing
program. Did I say typing? Many early computer hobbyists didn't even have
the interface allowing them to TYPE from a keyboard or teletype. The
"complete" Altair 8800 discussed above could only be programmed by entering
data via tiny little switches on its front panel, as either octal (base 8)
bytes or hexadecimal (base 16) bytes. With no television monitor available
either, the results of the program were read in binary (base 2) from lights
on that front panel. This may sound like the old story that begins with
the statement, "I had to walk five miles to school through snow three feet
deep when I was your age," but it helps to understand how things were at
this time to see what a leap forward the Apple II really was (er, will be.
Time travel complicates grammar!)
++++++++++++++++++++++++++++++
NEXT INSTALLMENT: The Apple I
++++++++++++++++++++++++++++++
NOTES
<1> Steven Levy, HACKERS: HEROES OF THE COMPUTER REVOLUTION, pp.
187-192.
<2> H. Edward Roberts and William Yates, "Altair 8800 Minicomputer,
Part 1", POPULAR ELECTRONICS, January 1975, pp. 33, 38. The
article is interesting also in some of the terminology that is
used. The Altair is described as having "256 eight-bit words" of
RAM. Apparently, the term "byte" was not in common use yet.
<3> Gene Smarte and Andrew Reinhardt, "15 Years of Bits, Bytes, and
Other Great Moments", BYTE, September 1990, pp. 370-371.
This is the ENTIRE series of articles that make up the Apple II
History. They are readable in either AppleWorks 2.x or 3.0, but will
require an expanded desktop for some segments.
Please feel free to make comments (on GEnie's A2 Roundtable, Category
2, Topic 16) or in E-mail (S.WEYHRICH) about the contents of these files.
PLEASE, if you detect any errors or have any corrections, let me know about
it. I would like to have as accurate a history as possible.
If you would like to print any of these files in a user group
newsletter, I only ask that you print any segment you use in its entirety,
and that you give me as the author credit for the work. Also, please send
me a copy of any newsletter in which it is printed. My address is:
Steven Weyhrich
Zonker Software
2715 N. 112th St.
Omaha, NE 68164-3666
(402) 498-0246
Enjoy!
APPLE II HISTORY
===== == =======
Compiled and written by Steven Weyhrich
(C) Copyright 1991, Zonker Software
(PART 2 -- THE APPLE I)
[v1.1 :: 12 Dec 91]
THE APPLE I: DEVELOPMENT
At the Homebrew Computer club in Palo Alto, California (in Silicon
Valley), Steve Wozniak, a 26 year old employee of Hewlett-Packard and a
long-time digital electronics hacker, had been wanting to build a computer
of his own for a long time. For years he had designed many on paper, and
even written FORTRAN compilers and BASIC interpreters for these theoretical
machines, but a lack of money kept him from carrying out his desire. He
looked at the Intel 8080 chip (the heart of the Altair), but at $179
decided he couldn't afford it. A decision to NOT use the 8080 was
considered foolhardy by other members of the club. Consider this
description of the microcomputer "world" as it was in the summer of 1975:
"That summer at the Homebrew Club the Intel 8080 formed the
center of the universe. The Altair was built around the 8080 and
its early popularity spawned a cottage industry of small
companies that either made machines that would run programs
written for the Altair or made attachments that would plug into
the computer. The private peculiarities of microprocessors meant
that a program or device designed for one would not work on
another. The junction of these peripheral devices for the Altair
was known as the S-100 bus because it used one hundred signal
lines. Disciples of the 8080 formed religious attachments to the
8080 and S-100 even though they readily admitted that the latter
was poorly designed. The people who wrote programs or built
peripherals for 8080 computers thought that later, competing
microprocessors were doomed. The sheer weight of the programs
and the choice of peripherals, so the argument went, would make
it more useful to more users and more profitable for more
companies. The 8080, they liked to say, had critical mass which
was sufficient to consign anything else to oblivion."<1>
Another chip, the Motorola 6800, interested Wozniak because it
resembled his favorite minicomputers (such as the Data General Nova) more
than the 8080. However, cost was still a problem for him until he and his
friend Allen Baum discovered a chip that was almost identical to the 6800,
while considerably cheaper. MOS Technology sold their 6502 chip for $25,
as opposed to the $175 Motorola 6800. Wozniak decided to change his choice
of processor to the 6502 and began writing a version of BASIC that would
run on it. A friend over at Hewlett-Packard programmed a computer to
simulate the function of the 6502, and Wozniak used it to test some of his
early routines. When his BASIC interpreter was finished, he turned his
attention to designing the computer he could run it on. Except for some
small timing differences, he was able to use the hardware design he had
earlier done on paper for the 6800.<2>
To make the computer easier to use, Wozniak favored a keyboard over
the front panel switches that came on the Altair. He also made it simple
to use a television for a video terminal. (Recall that at this time the
most common mechanism used for input/output was a teletype, which consisted
of a keyboard, typewriter, and if you were lucky, a paper tape
reader/puncher). Functionally, it was a television terminal attached to a
computer, all on one printed circuit board (another enhancement over the
Altair). Wozniak used two 256 x 4 PROM (programmable read-only memory)
chips to create a 256 byte program (called a "monitor") that looked at the
keyboard when the computer was turned on. This monitor program could not
do much more than allow entry of hex bytes, examine a range of memory, and
run a program at a specific address.<3> (The Altair needed these
"bootstrapping" instructions to be entered by hand each time the computer
was turned on).
Because there were no cheap RAMs available, Woz used shift registers
to send text to the TV screen. Consequently, his video terminal was
somewhat slow, displaying characters at about 60 characters per second, one
character per scan of the TV screen. (This speed would be similar to
watching a computer communicate via a modem at 1200 baud). It was slow by
1991 standards, but an advancement over the teletypes that could only type
10 characters per second. The computer had 8K of dynamic RAM. You could
load BASIC into 4K of memory and have 4K left over for your own programs.
It had a video connector, but you had to connect a monitor on your own.
You also had to buy the keyboard separately and wire it into a 16-pin DIP
connector. The power supply had to be connected to two transformers to get
5 volts and 12 volts for the motherboard. There was no speaker, no
graphics, and no color. There was a single peripheral slot, and when it
was first released there was nothing available to plug into this slot. It
was entirely contained on a single printed circuit board, about six by
eight inches in size (most hobby computers of that time needed at least two
boards), used only 30 or 40 chips, and because it could run BASIC programs
it got people's attention.<4>
THE APPLE I: MARKETING
Let's adjust our time circuits for 1976, and jump forward in time.
By now, Steve Wozniak had completed his 6502-based computer and would
display enhancements or modifications at the bi-weekly Homebrew Computer
Club meetings. Steve Jobs was a 21 year old friend of Wozniak's and also a
visitor at the Homebrew club. He had worked with Wozniak in the past
(together they designed the arcade game "Breakout" for Atari) and was very
interested in his computer. During the design process Jobs made
suggestions that helped shape the final product, such as the use of the
newer dynamic RAMs instead of older, more expensive static RAMs. He
suggested to Wozniak that they get some printed circuit boards made for the
computer and sell it at the club for people to assemble themselves. They
pooled their financial resources together to have PC boards made, and on
April 1st, 1976 they officially formed the Apple Computer Company. Jobs
had recently worked at an organic apple orchard, and liked the name because
"he thought of the apple as the perfect fruit--it has a high nutritional
content, it comes in a nice package, it doesn't damage easily--and he
wanted Apple to be the perfect company. Besides, they couldn't come up
with a better name."<5>
Jobs approached the owner of a new computer store in the bay area
called "The Byte Shop." This businessman, Paul Terrell, expressed an
interest in the Apple Computer (to be known later as the "Apple I"), but
wanted only fully assembled computers to sell. If they could provide this,
Terrell told them he would order fifty Apples, and pay cash on delivery.
Suddenly, the cost of making (and selling) this computer was considerably
more than they expected. Jobs and Wozniak managed to get the parts on "net
30 days" (30 days credit without interest), and set themselves up in Job's
garage for assembly and testing of the Apple I. After marathon sessions of
stuffing and soldering PC boards, Jobs delivered the computers to the Byte
Shop. Although these "fully assembled" computers lacked a power supply,
keyboard, or monitor, Terrell bought them as promised. In July of 1976 the
Apple I was released and sold for $666.66, which was about twice the cost
of the parts plus a 33% dealer markup.<6> Two hundred Apple I computers
were manufactured, and all except twenty-five of them sold over a period of
ten months.<7>
Although the Apple I was easier to begin using than the Altair
(thanks to its built-in ROM code), it was still a time consuming process to
set it up to do something useful. Steve Wozniak would have to type in
about 3K of hexadecimal bytes before BASIC was ready to use. He could do
it in about 20 to 30 minutes, but he almost knew the code by heart. The
typical user was more limited in ability to use BASIC on the Apple I. To
broaden the appeal of the Apple I (and at the insistence of Paul Terrell),
Wozniak designed a cassette interface. It was mounted on a small
two-inch-high printed circuit board and plugged into the single slot on the
motherboard. The card sold for $75 and a cassette tape of Woz's BASIC was
included with it. The advertisement Apple included with the card stated,
"Our philosophy is to provide software for our machines free or at minimal
cost." The interface worked, but worked well only with cassettes running
on expensive tape recorders. To further try to enhance sales, the Byte
Shop stores found a local cabinetmaker that made some koa-wood cases for
the Apple computer (so it would no longer be just a "naked" circuit
board).<8>
Interestingly, although most of the action in the micro world was
going on in Silicon Valley, news of the Apple I made its way east. Stan
Veit, owner of the east coast's first computer store, bought an Apple I and
took it to a meeting of the Association of Computer Machinery. Those
attending were quite skeptical that a REAL computer could fit into a small
briefcase; they were sure that the machine was just a portable terminal,
attached by a hidden phone line to a mainframe somewhere!<9>
+++++++++++++++++++++++++++++++
NEXT INSTALLMENT: The Apple II
+++++++++++++++++++++++++++++++
NOTES
<1> Michael Moritz, THE LITTLE KINGDOM, p. 123.
<2> Moritz, pp. 124-127.
<3> Williams & Moore, p. A69.
<4> Gregg Williams and Rob Moore, "The Apple Story, Part 1: Early
History", BYTE, Dec 1984, pp. A68-A69.
<5> Frank Rose, WEST OF EDEN: THE END OF INNOCENCE AT APPLE COMPUTER,
p. 33.
<6> Moritz, pp. 138-144.
<7> Williams & Moore, pp. A69.
<8> Moritz, pp. 147-149.
<9> Chien, Philip, "Apple's First Decade: A Look Back", THE APPLE II
REVIEW, Fall/Winter 1986, p. 12.
APPLE II HISTORY
===== == =======
Compiled and written by Steven Weyhrich
(C) Copyright 1991, Zonker Software
(PART 3 -- THE APPLE II)
[v1.1 :: 12 Dec 91]
THE APPLE II: HARDWARE AND FIRMWARE
Moving our time machine on to 1977, we can now look at Steve
Wozniak's next generation Apple. Even as the Apple I was completed and was
slowly selling, Wozniak was already working on making enhancements that
would make his computer faster and more functional. He wanted to make it
display in color. He worked to combine the terminal and memory functions
of the Apple I by moving the display into main memory, allowing instant
screen changes. Many of his changes were not added with the end user
specifically in mind. Wozniak stated:
"A lot of features of the Apple II went in because I had designed
Breakout for Atari. I had designed it in hardware. I wanted to
write it in software now. So that was the reason that color was
added in first--so that games could be programmed. I sat down
one night and tried to put it into BASIC. Fortunately I had
written the BASIC myself, so I just burned some new ROMs with
line drawing commands, color changing commands, and various BASIC
commands that would plot in color. I got this ball bouncing
around, and I said, 'Well it needs sound,' and I had to add a
speaker to the Apple II. It wasn't planned, it was just
accidental... Obviously you need paddles, so I had to scratch my
head and design a simple minimum-chip paddle circuit, and put on
some paddles. So a lot of these features that really made the
Apple II stand out in its day came from a game, and the fun
features that were built in were only to do one pet project,
which was to program a BASIC version of Breakout and show it off
at the club."<1>
Wozniak added other features that he felt were important for a
computer that was useful, one that he would want to own. Since the 6502
processor could address a total of 64K of memory, he designed the computer
with the ability to use either 4K RAM chips, or the newer (and more
expensive) 16K RAM chips. The first Apple II's came standard with 4K of
memory, and more could be added, to a maximum of 12K (if using the 4K
chips) or 48K (if using the 16K chips). Specially wired strapping blocks
attached to the motherboard told the Apple II how much memory was present
and where it was. According to the 1981 edition of the APPLE II REFERENCE
MANUAL, the Apple could have memory in the following sizes: 4K, 8K, 12K,
16K, 20K, 24K, 32K, 36K, or a full 48K. (These sizes were determined by
the different ways that three RAM chips, either 4K or 16K, could be
installed). The strapping blocks were even designed with the flexibility
of allowing blank spots in memory if there were no RAM chips available to
fill those spots.
The first 4K of memory always had to have RAM present, since it was
used by the 6502 processor, the ROM routines, and the text screen display.
If, for example, you only had two other 4K RAM chips to install and you
wanted to display hi-res graphics, you could strap one chip to the lower
half of hi-res memory from $2000-$2FFF, and the other to the upper half of
hi-res memory from $3000-$3FFF.<2> Since 16K RAM chips cost about $500
when Wozniak designed the Apple II, not many users could afford them.
Whereas the Commodore PET and the Radio Shack TRS-80 could not easily be
expanded beyond the 4K they came with, the Apple II from the beginning was
designed with expansion in mind.<3>
The row of eight expansion slots was another feature about the
Apple II that was a strong selling point. Unlike the TRS-80 or PET, you
could easily expand the Apple II by simply plugging a card into one of
these slots. This degree of expandability made it more expensive to build,
however. Steve Jobs didn't believe that anyone would ever need more than
two slots, one for a printer and one possibly for a modem. Wozniak knew
from his experience with computers at Hewlett-Packard that computer users
would always find SOMETHING to fill those extra slots, and insisted that
they keep the number at eight.<4>
One problem Apple had to deal with was getting FCC approval for the
computer. The RF (radio frequency) modulator that had been designed gave
off too much interference, and it was probable that the FCC would not
approve it. (The RF modulator allowed a user to attach the Apple to a
standard television receiver, instead of requiring the purchase of an
expensive computer monitor). Rather than have the release of the Apple II
delayed for re-engineering of the RF modulator to get that FCC approval,
Apple gave the specifications for the RF modulator to Marty Spergel. He
ran a small company (called M&R Electronics) that specialized in obtaining
hard-to-get parts that electronics and computer hackers wanted for their
projects. Their agreement allowed M&R to make and sell the RF modulators,
while Apple could concentrate on making and selling the Apple II. Dealers
would sell an Apple II with a "Sup'r Mod" (costing about $30) if the buyer
wanted to see the graphics on their color TV. Jobs assured Spergel that
the item would sell well, maybe as many as fifty units a month. (Years
later Spergel estimated that he had sold about four hundred thousand Sup'r
Mods).<5>
Other features that Wozniak (and Allen Baum, who helped him with the
project) included in the Apple II ROMs included the terminal software to do
screen text display, expanded Monitor functionality, and cassette
input/output routines. They added the ability to split the screen into
different sized windows. They also wrote a disassembler, which was one of
the most important features of the Apple II from the beginning and a
significant part of its open design. It allowed ANYONE to view the 6502
code that ANY program used, and matched the philosophy of the Homebrew Club
of making all computer knowledge available to everybody. In the Apple I
days, when Apple was supplying software "free or at minimal charge",
Wozniak and Baum published an early version of their 6502 disassembler in a
hacker's magazine. It was designed to be loaded in memory on the Apple I
from $800 to $9D8 and the routine could be executed from the monitor. This
early code was quit similar to the disassembler that was later included in
the Apple II ROM.<6>
Having an expanded Monitor program in ROM and color graphics were not
the only features in the Apple II that attracted people to it. Having
Wozniak's BASIC language in ROM, available immediately when the power was
turned on, made it possible for non-hackers to write programs that used the
Apple II's color graphics.
An interesting bit of trivia about Wozniak's Integer BASIC was that
he never had an assembly language source file for it. He wrote it in
machine language, assembling it by hand on paper:
"I wrote this BASIC processor, and I wrote a little ALGOL
simulator and got it simulated. It looked like it would work,
but I had forgotten to build the machine. I had no assembler,
that was another thing. To use an assembler, they figured that
somebody was going to buy this processor [the 6502] to use for a
company, and their company can pay a few thousand dollars in
time-sharing charges to use an assembler that was available in
time-share. I didn't have any money like that, so a friend
taught me that you just sort of look at each instruction, you
write your instructions on the right side of the page, you write
the addresses over on the left side, and you then look up the hex
data for each instruction--you could assemble it yourself. So I
would just sit there and assemble it myself. The [Integer]
BASIC, which we shipped with the first Apple II's, was never
assembled--ever. There was one handwritten copy, all
handwritten, all hand-assembled. So we were in an era that we
could not afford tools."<7>
Even to this day there is not an official source code listing of
Integer BASIC at Apple. And interestingly, the only error I am aware of in
the Integer interpreter is one involving a single byte. If a line is
entered that has too many parentheses, the "TOO LONG" error message is
displayed instead of the "TOO MANY PARENS" message.<8>
NOW A WORD FROM OUR SPONSOR: BACK TO THE BASICS...
I want to take a short break in this discussion of the Apple II
firmware to look at some other items that will make further descriptions
easier to understand. If you are a programmer already, you may want to
skip this section, since you probably already know this stuff. First we
will examine some definitions of terms that are commonly known to
programmers, but possibly not to you. Next will be a brief excursion into
the realm of hexadecimal, and finally a look at the memory map of the
original Apple II.
First, let's look at definitions of some words that I have been
loosely throwing around:
BIT The smallest piece of information that a computer can deal
with, it is either a "0" (off, clear) or a "1" (on, set).
BYTE The most convenient piece of information (for humans) that
computers use. One byte consists of eight bits, and ranges
from "00000000" (0 decimal) to "11111111" (255 decimal).
NIBBLE (also spelled "nybble"). One half of a byte, consisting of
four bits, ranging from "0000" (0 decimal) to "1111" (15
decimal).
WORD Two bytes (or four nibbles, if you prefer), consisting of
sixteen bits, and ranging from "00000000 00000000" (0
decimal) to "11111111 11111111" (65535 decimal). Not used
much in microcomputers.
BINARY A system of counting using only two digits, "0" and "1"
(base 2). Computers speak in binary at their most basic
level; anything else is translated into binary, so the
computer can understand it.
DECIMAL A system of counting using ten digits, "0" through "9"
(base 10). Most of the Western world uses this system.
HEXADECIMAL A system of counting using sixteen digits, "0" through "9"
and "A" through "F" (base 16). Programmers use this system
as a convenient way of organizing groups of binary numbers.
KILOBYTE Abbreviated "K", "KB", or "Kbytes", it refers to 1,024
bytes. A 64K computer has 64 x 1024 = 65536 bytes.
MEGABYTE Abbreviated "M", "MB", or "meg", it refers to 1,024 Kbytes,
or 1,024 x 1,024 = 1,048,576 bytes. A 32 MB hard disk, the
largest size volume that ProDOS can handle, holds 32 x 1,024
= 32,768 Kbytes, or 32 x 1,024 x 1,024 = 33,554,432 bytes.
GIGABYTE Abbreviated "G", "GB", or "gig", it refers to 1,024 MB, or
1,048,576 Kbytes, or 10,737,441,824 bytes. The Apple II
Smartport (which will be mentioned later in this history)
can handle disk devices up to 4 gig in size (although the
software to handle that type of size has yet to be written).
RAM Random Access Memory. Any data stored in this memory
disappears when the computer is turned off.
ROM Read Only Memory. Data cannot be stored in this type of
memory, but instead it usually contains programs or other
information that does not disappear when the computer is
turned off.
HARDWARE The physical electronic components and mechanical parts
that make up a piece of computer equipment. Examples would
be the keyboard, disk drive, or television monitor (also
called CRT, or Cathode Ray Tube).
SOFTWARE The digital instructions executed by the computer in RAM.
They may act on the hardware that is attached to the
computer. Examples would be a BASIC or Pascal program, an
assembly language routine to read a clock, or a disk
operating system. Since software is executed in RAM, it
disappears from memory when the computer is turned off.
FIRMWARE The same as software, except it is executed from ROM, and
does not disappear when the computer is turned off. Almost
any software could be in ROM, except programs that modify
themselves as they run.
Next, let's look at hexadecimal numbers in more detail. Since
computers deal in binary (base 2), the true language of computers is either
in terms of "0" (off) or "1" (on). However, it quickly becomes cumbersome
to refer to large numbers in binary; the base 10 number "458" is
"111001010" in binary. So programmers have decided to group numbers in
such a way as to make it easy to convert part or all of that number to
binary if necessary, but still have numbers (almost) as easy to deal with
as our standard base 10 system.
Now, in the familiar base 10 system there are ten digits, 0 through
9. When counting, after you pass 9, you add one to the digit to the left
of the 9, change the 9 to a 0, and continue. So, "09" becomes "10", "19"
becomes "20", and so on. However, in the base 16 system there are sixteen
digits, 0 through 9, and then A through F (representing decimal 10 through
15). When counting, then, you go 7, 8, 9, then A (not 10), B, C, D, E, F,
10, 11, 12, and so on. In the Apple world we have traditionally used a
preceding dollar sign to signify a hexadecimal number, so "25" means
twenty-five, but "$25" means thirty-seven (2 x 16, plus 5). To translate a
hexadecimal number to decimal, use powers of 16:
$B65F = (11 x 16^3) + (6 x 16^2) + (5 x 16^1) + (15 x 16^0)
= (11 x 4096) + (6 x 256) + (5 x 16) + (15 x 1)
= 45056 + 1536 + 80 + 15
= 46687
The same thing can be done in reverse to convert base 10 to
hexadecimal, starting by dividing the number by 4096, then the remainder by
256, then 16. If the number is greater than 65536, you need a bigger power
of 16 (and you are probably not dealing with an 8-bit Apple II!) Or you
can just get a programmer's calculator like mine that automatically does
the conversion for you...
When dealing with memory addresses on an Apple II, we usually
designate them as four digit hex numbers (such as the $B65F example above).
Numbers less than $1000 often are printed without the leading blank ($400
instead of $0400), and numbers less than $100 are treated the same way ($32
instead of $0032).
THE APPLE II: MEMORY MAP
To understand the memory layout of the Apple II, consider this
analogy: Imagine a cabinet with sixteen shelves, and sixteen separate
slots or pigeon holes on each shelf (similar to those found in old roll-top
desks). Each slot refers to a specific address in memory on the computer,
and each slot can hold a number between 0 and 255. (Since a byte is eight
bits wide, the largest number that can be represented by eight binary bits
is 255). The bottom shelf is row "0", and the leftmost slot in that row is
slot "0". The address of that slot, then, is $00. As we move to the
right, the addresses increase, $01, $02, $03, and so on to $0F at the end.
We then go up to the next row, (row "1"), and the addresses continue in the
same fashion with $10, $11, $12, and so on as before. The sixteenth row is
row "F", the rightmost slot in that row is slot "F", and the address of
that slot is $FF. This cabinet has, then, 256 slots (16 x 16), and
represents what is called a "page" in the Apple memory. The cabinet itself
has an address (since computers need addresses for everything), and this
one's address is "00". The full address of row "5", slot "A" on cabinet
"00" is $005A.
Only the Altair 8800 came with just 256 bytes of memory, so we have
to account for the entire 64K memory space that the 6502 chip in the
Apple II can handle. There is a cabinet sitting on top of cabinet "00",
and it is laid out in the same fashion with its 256 slots in sixteen rows.
This is cabinet "01", and on top of that one is cabinet "02"; this
continues on up until we reach cabinet "FF" way up at the top. Apple
programmers refer to these cabinets as "pages" of memory. There are 256
pages of memory, each with 256 bytes on a page, making a grand total of 256
x 256 = 65536 bytes of memory (or slots that can hold a number, if you
prefer the analogy).
In discussing the memory map on the Apple II, we can refer to pages
of memory with a hexadecimal two-digit number for shorthand if we wish.
The general layout of the Apple II memory is as follows:
Page $00: used by the 6502 processor for storage of information that
it can access quickly. This is prime real-estate that is
seldom available for general use by programmers without
special care.
Page $01: used by the 6502 for internal operations as a "stack."
Page $02: used by the Apple II firmware as an input buffer when using
the keyboard from BASIC, or when a program uses any of the
firmware input routines.
Page $03: general storage area, up to the top three rows (from $3D0
through $3FF) which are used by the disk operating system
and the firmware for pointers to internal routines.
Pages $04-$07: used for the 40 column text screen.
Pages $08-$BF: available for use by programs, operating systems, and for
hi-res graphics. Within this space, Woz designated pages
$20-$3F for hi-res "page" one, and pages $40-$5F for hi-res
"page" two.
Page $C0: internal I/O and softswitches
Pages $C1-$C7: ROM assigned to each of the seven peripheral cards
Pages $C8-$CF: switchable ROM available for any of the seven cards
Pages $D0-$D7: empty ROM socket #1
Pages $D8-$DF: empty ROM socket #2
Pages $E0-$F7: Integer BASIC ROM
Pages $F8-$FF: Monitor ROM
The memory space on the Apple II between $C000 and $CFFF was assigned
to handle input and output. From $C000 to $C0FF the space was reserved for
various soft-switches used to control the display, and various built-in I/O
devices, such as the keyboard, paddles, annunciators, and the cassette
port. (A soft-switch is simply a memory location that, when a number is
stored there, changes something in the computer--such as switching on
graphics mode). From $C100 to $CFFF the space was reserved for ROM on the
plug-in peripheral cards for each of the seven slots. Slot 1 was given the
space from $C100 to $C1FF, slot 2 from $C200 to $C2FF, and so on. The
$C800 to $CFFF space was special slot-selectable ROM that was uniquely
available for each of the seven peripheral cards. For example, a program
running on the card in slot 6 to control a device could use the $C800-$CFFF
space for its own purpose. When control passed to the card in slot 3, that
card could use a program of its own that ran in the same $C800-$CFFF space.
This was accomplished by allowing each card to have ROM code that covered
pages $C8-$CF, and making that space "switchable", depending on which card
wanted to use it. Having this space available made writing ROM code
simpler, since it would not have to be capable of running at various memory
locations (depending on which slot a card was plugged into).
The memory from $D000 to $D7FF and $D800 to $DFFF was empty on all
early Apple II computers. On the motherboard were two empty sockets that
were available for the user to plug in their own ROM chips. The
$D000-$D7FF space was most often used by a plug-in ROM chip sold by Apple,
known as "Programmer's Aid #1." It contained various utilities for Integer
BASIC programmers, including machine language routines to do the following:
Renumber BASIC programs
Append one BASIC program to the end of another
Verify a BASIC program that had been saved on tape (to confirm it was
an accurate save)
Verify non-program data that had been saved on tape
Relocate assembly language routines to a different location in memory
(most would only run in one place in memory)
Test the Apple II RAM
Generate musical tones through the built-in speaker
Handle hi-res graphics from BASIC, including code to clear the hi-res
screen, set colors, plot points and lines, draw shapes, and load
shapes from tape.
All the routines on the Programmer's Aid #1 ROM were written by
Wozniak between June 1977 (the RAM test routine) and April 1978 (program
renumber and append), except for the music routine, which was written by
Gary Shannon.
The other empty ROM socket (covering memory from $D800 to $DFFF) was
never filled by Apple. Various third-party vendors sold ROMs for that
socket (or for the $D000-$D7FF socket used by the Programmer's Aid #1 ROM),
but none made enough of an inroad to be preserved in the INTBASIC file that
would later be included on the DOS 3.3 System Master disk. In fact, the
$D800-$DFFF space in the INTBASIC file on that disk contains an image of
that same space taken directly from the Applesoft ROM! It is completely
useless to Integer BASIC, of course, but disk files being what they are,
Apple had to fill that space with SOMETHING!
The Integer BASIC interpreter lived in the ROM space between $E000
and $F7FF. However, BASIC only used the space up to $F424. Between
$F425-$F4FB and $F63D-$F65D could be found a floating-point math package
that was not used by Integer BASIC, but was available for BASIC programmers
who were astute enough to figure out how it worked. (An early Apple user
group, the Apple Pugetsound Program Library Exchange, or A.P.P.L.E., sold a
tape and notes by Steve Wozniak they called "Wozpak", that documented some
of the secrets of the Integer BASIC ROM). Between $F500-$F63C there was
code that was known as the "miniassembler", which was executed starting at
the ominous address $F666. The miniassembler allowed you to enter short
machine language programs using the standard 6502 mnemonics (the three
letter codes that referred to a specific type of operation; for example,
"LDA #" represented the 6502 opcode $A9) instead of entering the program
byte by byte in the monitor. The $F689-$F7FC space contained Woz's
SWEET 16 interpreter. Wozniak wrote SWEET 16 to simulate a 16-bit
processor; it simplified some routines he wrote for the Apple II ROMs,
including the Programmer's Aid #1 renumber, append, and relocate routines.
Simply put, he took a series of hex bytes, defined them as "opcodes" the
way HE wanted them to function, and when executing the code used his
SWEET 16 interpreter to translate the code into legal 6502 operations. It
ran slower than standard 6502 code, but when memory space was at a premium
it was better to have a slow program than to not have enough room for the
program at all.
For those who are keeping count, there are a few unreferenced bytes
in the latter part of the Integer ROM. Those bytes contained filler bytes
that were not used as any program code.<9>,<10>,<11>
The last part of the Apple II memory, from $F800-$FFFF, contained
Wozniak's Monitor program which has already been discussed above.
++++++++++++++++++++++++++++++++++++++
NEXT INSTALLMENT: The Apple II, cont.
++++++++++++++++++++++++++++++++++++++
NOTES
<1> Jack Connick, "...And Then There Was Apple", CALL-A.P.P.L.E., Oct
1986, p. 24.
<2> -----, "Memory Organization", APPLE II REFERENCE MANUAL, 1979,
1981, pp. 70-73.
<3> Val J. Golding, "Applesoft From Bottom To Top", CALL-A.P.P.L.E.
IN DEPTH #1, 1981, p. 8.
<4> Michael Moritz, THE LITTLE KINGDOM, p. 157.
<5> Steven Levy, HACKERS: HEROES OF THE COMPUTER REVOLUTION, pp.
260-261.
<6> Steve Wozniak and Allen Baum, "A 6502 Disassembler From Apple",
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Sep
1976, pp. 22-25.
<7> Jack Connick, p. 23.
<8> Christopher Volpe, "Beep: A Tale of (T)ERROR", CALL-A.P.P.L.E.,
Mar 1983, p. 114.
<9> Bob Bragner, "Open Discussion", SOFTALK, Nov 1983, pp. 51-52.
<10> -----, PROGRAMMER'S AID #1, 1978.
<11> Dick Sedgewick, "SWEET 16 - Introduction", MERLIN USER'S MANUAL,
1982, pp. 103-109.
APPLE II HISTORY
===== == =======
Compiled and written by Steven Weyhrich
(C) Copyright 1991, Zonker Software
(PART 4 -- THE APPLE II, CONT.)
[v1.1 :: 12 Dec 91]
THE APPLE II: OTHER DESIGN FEATURES
Since Steve Wozniak was the designer of the Apple I and II, exactly
what contribution did Steve Jobs make to the effort? Unlike Wozniak, who
would not think much of extra wires hanging out of a computer that worked
properly, Jobs had an eye for the appearance of the final product. He
wanted the Apple II to be a product that people outside the Homebrew
Computer Club would want to own:
"Jobs thought the cigar boxes [housing the home-made computers]
that sat on the ... desk tops during Homebrew meetings were as
elegant as fly traps. The angular, blue and black sheet-metal
case that housed Processor Technology's Sol struck him as clumsy
and industrial ... A plastic case was generally considered a
needless expense compared to the cheaper and more pliable sheet
metal. Hobbyists, so the arguments went, didn't care as much for
appearance as they did for substance. Jobs wanted to model the
case for the Apple after those Hewlett-Packard used for its
calculators. He admired their sleek, fresh lines, their hardy
finish, and the way they looked at home on a table or desk."<1>
The final case design made the Apple II look quite different from
most of their competition. The other computers looked like they had been
assembled at home (and many of them were). The Apple had no visible screws
or bolts (the ten screws attached at the bottom). It had the appearance of
some variation of a typewriter, but still looked futuristic enough to be a
computer. The friendliness of the design even extended to the lid, which
popped off easily to allow access to the expansion slots, almost inviting
the user to look inside (unlike most electronic devices that held the
warning "CAUTION! NO USER SERVICEABLE PARTS INSIDE").<2>
Other aesthetics to which Jobs paid attention were the color of the
keyboard, vents for heat dissipation (avoiding the need for a noisy fan),
and a shape and color that would blend in with other items in a home or on
a desk. He also hired an engineer who was good with analog circuitry (not
Wozniak's area of interest) to design a reliable, lightweight power supply
that would stay cool. The engineer, Rod Holt, was working at Atari at the
time, but was convinced to help Jobs and Wozniak. He developed a new
approach (for microcomputers) by taking household current and switching it
on and off rapidly, producing a steady current that was safe for the
expensive memory chips. The final design of this switching power supply
was smaller than a quart carton of milk and was quite reliable. Holt also
helped design the television interface for the Apple II.<3>
The new company was racing to have the Apple II ready for the First
West Coast Computer Fair in April of 1977. Some last minute bugs had to be
eliminated; because of a static electricity problem affecting a sensitive
chip, the keyboards went dead every twenty minutes. Chris Espinosa and
Randy Wigginton, two high school students who were early employees of
Apple, had written programs to demonstrate the computer's color and sound.
They were hurriedly working to duplicate these programs on cassette.
People at Apple were working to fix blemishes in the computer cases that
had returned from the plastics molding company. The name for this new
computer was also finalized as "Apple II", following the example of Digital
Equipment Company, who had given each newer version of its PDP series a
higher number (PDP-1, PDP-6, etc.). They stylized the "II" in the product
name by using right and left brackets, and displaying it on the case as
"][". The final product bore the mark of each person at Apple:
"The computer that appeared at the West Coast Computer Faire was
not one person's machine. It was the product of collaboration
and blended contributions in digital logic design, analog
engineering, and aesthetic appeal. The color, the slots, the way
in which the memory could be expanded from 4K to 48K bytes, the
control of the keyboard and hookup to the cassette recorder, and
the BASIC that was stored in the ROM chip--in effect the
motherboard--was Wozniak's contribution. Holt had contributed
the extremely significant power supply, and Jerry Mannock the
case. The engineering advances were officially recognized when,
some months later, Wozniak was awarded U.S. Patent #4,136,359 for
a microcomputer for use with video display, and Holt was given
Patent #4,130,862 for direct current power supply. But behind
them all Jobs was poking, prodding, and pushing and it was he,
with his seemingly inexhaustible supply of energy, who became the
chief arbiter and rejector... [Finally,] the combination of
[Mike] Markkula [Apple's first president], Jobs, and the McKenna
Agency turned Apple's public bow [at the West Coast Computer
Faire] into a coup."<4>
THE APPLE II: PRODUCT INTRODUCTION
As they prepared for the display at the First West Coast Faire, it
was decided to create a new corporate logo. The original one, used in
sales of the Apple I, was a picture of Isaac Newton sitting under an apple
tree, with a phrase from Wordsworth: "Newton...'A Mind Forever Voyaging
Through Strange Seas of Thought...Alone.'" Jobs had been concerned that
the logo had part of the slow sales of the Apple I, and the Regis McKenna
Agency was hired to help in the design of a new one.
"Rob Janov, a young art director, was assigned to the Apple
account and set about designing a corporate logo. Armed with the
idea that the computers would be sold to consumers and that their
machine was one of the few to offer color, Janov set about
drawing still lifes from a bowl of apples ... He gouged a rounded
chunk from one side of the Apple, seeing this as a playful
comment on the world of bits and bytes but also as a novel
design. To Janov the missing portion 'prevented the apple from
looking like a cherry tomato.' He ran six colorful stripes
across the Apple, starting with a jaunty sprig of green, and the
mixture had a slightly psychedelic tint. The overall result was
enticing and warm ..."
"[Steve] Jobs was meticulous about the style and appearance
of the logo ... When Janov suggested that the six colors be
separated by thin strips to make the reproduction easier, Jobs
refused."<5>
For the Faire, Markkula had ordered a smoky, backlit, illuminated
plexiglas sign with the new logo. Although Apple had a smaller booth than
other companies displaying their products at the Faire, and some of the
other microcomputer makers (Processor Technology, IMSAI, and Cromemco) had
been in business longer, Apple's booth looked far more professional, thanks
to Markkula's sign. Some of the other participants, companies larger than
Apple, had done no more than use card tables with signs written in black
markers.
Because they had been one of the first to commit themselves to
displaying at the Faire, Apple's booth was near the entrance and was
visible to everybody entering the convention center. They demonstrated a
kaleidoscopic video graphics program (possibly an early version of "BRIAN'S
THEME") on a huge Advent display monitor, catching everybody's attention.
But, after the Faire its organizer Jim Warren (Homebrew club member and
editor of DR. DOBB'S JOURNAL) didn't think that Apple was a strong
exhibitor. Byte magazine, in their report of the show, failed to even
mention Apple. Despite these early opinions by influential people, over
the next few months Apple received about three hundred orders for the
Apple II, over a hundred more than the total number of Apple I's sold.<6>
THE APPLE II: COST
Prebuilt systems were also sold by Commodore (the 6502-based PET, for
$595), and Radio Shack (the Z80-based TRS-80, for $600). This was quite a
bit less than the Apple II's premium price of $1,298 for a 4K computer, a
pair of game paddles, and an audio cassette with demo programs. This price
did not include a cassette recorder or monitor (which both the PET and
TRS-80 did include). The hardware limitations and lack of expandability of
those machines, however, offset some of the price difference. Also, one
other hardware introduction for the Apple II that happened in mid-1978 set
it well ahead of its immediate competitors; we'll get to that shortly.
THE APPLE II: EXPERIENCES OF EARLY USERS
The original manual for the Apple II was sparse. It consisted of
thirty photocopied pages, including some handwritten notes from Woz. The
cover stated, "simplicity is the ultimate sophistication: introducing
Apple ][, the personal computer." In early 1978 these original photocopied
manuals were replaced with the new "Apple II Technical Reference Manual"
(also known as the "Red Book"), and copies were mailed to previous
customers. Steve Jobs realized that people often viewed the quality of a
product by the quality of its documentation, and so he took pains to get
manuals that were easy to read and had a professional appearance.<7>
Setting up an early Apple II was fairly simple. The lid popped off
easily, and one of the first things you would attach was the Sup'r Mod (RF
modulator). This was plugged onto two pins sticking up from the back rear
of the motherboard, near the video output jack (assuming that you did not
also buy a REAL computer monitor). The game paddles were two small black
boxes, with a knob on the top attached to a potentiometer (similar to
volume controls on a radio) and a tiny black button on the side. These
boxes were attached via a narrow cable to a plug that looked (and was)
fragile; this plug also went into a small socket in the motherboard.
Lastly, you attached your data storage device (the cassette recorder) to
the input and output jacks in the back of the computer.
After turning on the Apple II, the first thing to greet you was a
screen full of random alphabetic characters and symbols, and possibly some
colored blocks (lo-res graphics mode might be turned on). Here you had to
press the RESET key in the upper right hand side of the keyboard, which,
after releasing the key, would cause a "beep!" and an asterisk to appear in
the bottom left-hand corner of the screen. (If the lo-res graphics mode
had been on, it would now be off). Next to the asterisk (which was a
prompt to show that you were in the Monitor) was a flashing box, the
cursor. To get into BASIC, you had to press the "Ctrl" key and the "B" key
simultaneously. Now you would see a different prompt, one that looked like
a ">".
At this point, you could either begin entering a BASIC program, or
try to load one from cassette. To load from cassette was not always easy;
it took time to get the right volume and tone settings on the tape player
in order to avoid getting the "ERR" or "*** SYNTAX ERR" message. (And if
you didn't have much memory, you might get a "*** MEM FULL ERR" message!)
When you got it properly loaded, you could type RUN and see what happened.
Beyond that, it was more or less up to you to actually find something to DO
with your new toy.<8>
THE APPLE II: EARLY HARDWARE ADD-ONS
Aside from the M&R "Sup'r Mod" that allowed early Apple II users to
run their computer on their color TV's, some other enterprising hackers
designed their own versions of modulators. One used by an early member of
an Apple user group in Washington State (Apple Pugetsound Program Library
Exchange, or A.P.P.L.E.) was somewhat better shielded than the "Sup'r Mod".
It had its own power supply and plugged into the video output jack on the
back of the Apple. The "Sup'r Mod" was by far the biggest seller,
however.<9>
At first, there were no interface cards for any of Woz's eight slots.
With the limited funds that computer purchasers had then (and now) there
was not much they could afford after shelling out anywhere from $1200 to
$1800 just to get their own Apple II. But they were innovative, and like
many other hardware hackers of the day managed to make do with old or
surplus parts. Some people, for instance, had gotten their hands on used
teletype printers, such as the ASR-33 (called "battleships" because they
were so rugged and heavy). Since there weren't any printer interface cards
to plug into the slots to allow the computer to communicate with the
teletype, they used a trick they learned from Woz himself. The Apple II
had four single-bit output pins on the game controller socket that could be
used for various purposes. A schematic floated through the various user
groups that showed how to connect the teletype to an annunciator pin; along
with it was a machine language program that re-directed output from the
screen to that one-bit port, and on to the printer.<10>
++++++++++++++++++++++++++++++
NEXT INSTALLMENT: The Disk II
++++++++++++++++++++++++++++++
NOTES
<1> Michael Moritz, THE LITTLE KINGDOM, p. 186.
<2> Steven Levy, HACKERS: HEROES OF THE COMPUTER REVOLUTION, pp.
263-264.
<3> Moritz, p. 189.
<4> Moritz, pp. 190-191.
<5> Moritz, p. 188.
<6> Moritz, pp. 192-193.
<7> Philip Chien, "The First Ten Years: A Look Back", THE APPLE II
REVIEW, Fall/Winter 1986, p. 12.
<8> -----, APPLE II BASIC PROGRAMMING MANUAL, 1978, 1979, 1980, 1981,
pp. 1-19.
<9> -----, "A.P.P.L.E. Co-op Celebrates A Decade of Service",
CALL-A.P.P.L.E., Feb 1988, pp. 12-27.
<10> Val J. Golding, "Applesoft From Bottom To Top", CALL-A.P.P.L.E.
IN DEPTH #1, 1981, p. 8.
APPLE II HISTORY
===== == =======
Compiled and written by Steven Weyhrich
(C) Copyright 1991, Zonker Software
(PART 5 -- THE DISK II)
[v1.1 :: 12 Dec 91]
THE DISK II
Let's put some more trash into Mr. Fusion to fuel the next leg of our
trip. How about one of those KIM-1 computers over there in the corner of
the Computer Faire auditorium? We might have to break it up a bit to make
it fit ... Okay, now we'll just make a small jump, to December of 1977. By
this time the Apple II had been generally available for about six months.
Most customers used their television as an inexpensive color monitor, and
used a cassette recorder to store and retrieve their programs and data.
Apple's major competitors were the TRS-80 and the Commodore PET. The
products made by these two companies, together with Apple, could be
considered as the second generation of microcomputers; they all came fully
assembled and ready to use out of the box, with a keyboard and cassette
interface. The TRS-80 and the PET even came with a monitors and cassette
recorders. The strength of the Apple was expandability and graphics, while
the strength of the others was cost (both the TRS-80 and the PET sold for
around $600, half the price of the Apple II).
By late 1977, Apple had introduced some enhancements to the II,
including their first version of a floating point BASIC (called
"Applesoft") on cassette, and a printer interface card to plug into one of
the slots on the motherboard. But the Apple II still needed something to
make it more attractive to buyers, to stand out above the TRS-80 and the
PET. One area that needed improvement was its program and data storage and
retrieval system on cassette; it was a continued source of frustration for
many users. The cassette system used on the TRS-80 was more sophisticated
than that of the Apple II, allowing named files and easier storage of files
and data on the same tape. On the Apple II it took VERY careful adjustment
of the volume and tone controls on the cassette recorder to get programs or
data to successfully load. The Apple cassette system also needed careful
attention to the location on the tape where a program was stored, and was
no more accurate than the number on the recorder's mechanical tape counter
(if it had one).
Apple president Mike Markkula was one Apple II user that was
dissatisfied with cassette tape storage. He had a favorite checkbook
program, but it took two minutes to read in the program from the tape, and
another two minutes to read in the check files.<1> Consequently, at the
executive board meeting held in December 1977 he made a list of company
goals. At the top of the list was "floppy disk". Although Wozniak didn't
know much about how floppy disks worked, he had once looked through a
manual from Shugart (a Silicon Valley disk drive manufacturer):
"As an experiment Woz had [earlier] conceived a circuit that
would do much of what the Shugart manual said was needed to
control a disk drive. Woz didn't know how computers actually
controlled drives, but his method had seemed to him particularly
simple and clever. When Markkula challenged him to put a disk
drive on the Apple, he recalled that circuit and began
considering its feasibility. He looked at the way other computer
companies--including IBM--controlled drives. He also began to
examine disk drives--particularly North Star's. After reading
the North Star manual, Woz knew that his circuit would do what
theirs did and more. He knew he really had a clever design."<2>
Other issues that Wozniak had to deal with involved a way to properly
time the reading and writing of information to the disk. IBM used a
complex hardware-based circuit to achieve this synchronization. Wozniak,
after studying how IBM's drive worked, realized that if the data was
written to the disk in a different fashion, all that circuitry was
unneeded. Many floppy disks sold at that time were "hard sectored",
meaning that they had a hole punched in the disk near the center ring.
This hole was used by the disk drive hardware to identify what section of
the disk was passing under the read/write head at any particular time.
Wozniak's technique would allow the drive to do self-synchronization ("soft
sectoring"), not have to deal with that little timing hole, and save on
hardware.
Wozniak asked Randy Wigginton for help in writing some software to
control the disk drive. During their week of Christmas vacation in 1977
they worked day and night creating a rudimentary disk operating system,
working hard to get the drive ready to demonstrate at the Consumer
Electronics Show in the first week of 1978. Their system was to allow
entry of single letter commands to read files from fixed locations on the
disk. However, even this simple system was not working when Wozniak and
Wigginton left for the show.
When they got to Las Vegas they helped to set up the booth, and then
returned to working on the disk drive. They stayed up all night, and by
six in the morning they had a functioning demonstration disk. Randy
suggested making a copy of the disk, so they would have a backup if
something went wrong. They copied the disk, track by track. When they
were done, they found that they had copied the blank disk on top of their
working demo! By 7:30 am they had recovered the lost information and went
on to display the new disk drive at the show.<3>,<4>
Following the Consumer Electronics Show, Wozniak set out to complete
the design of the Disk II. For two weeks, he worked late each night to
make a satisfactory design. When he was finished, he found that if he
moved a connector he could cut down on feedthroughs, making the board more
reliable. To make that move, however, he had to start over in his design.
This time it only took twenty hours. He then saw another feedthrough that
could be eliminated, and again started over on his design. "The final
design was generally recognized by computer engineers as brilliant and was
by engineering aesthetics beautiful. Woz later said, 'It's something you
can ONLY do if you're the engineer and the PC board layout person yourself.
That was an artistic layout. The board has virtually no feedthroughs.'"<5>
THE DISK II: COST
The Disk II was finally available in July 1978 with the first full
version of DOS, 3.1. It had an introductory price of $495 (including the
controller card) if you ordered them before Apple had them in stock;
otherwise, the price would be $595. Even at that price, however, it was
the least expensive floppy disk drive ever sold by a computer company.
Early production at Apple was handled by only two people, and they produced
about thirty drives a day.<6>,<7>
Apple bought the drives to sell with Woz's disk controller from
Shugart, right there in Silicon Valley. To cut costs, however, they
decided to go to Alps Electric Company of Japan and ask them to design a
less expensive clone. According to Frank Rose, in his book "West Of Eden":
"The resulting product, the Disk II, was almost obscenely
profitable: For about $140 in parts ($80 after the shift to
Alps) [not counting labor costs], Apple could package a disk
drive and a disk controller in a single box that sold at retail
for upwards of $495. Better yet was the impact the Disk II had
on computer sales, for it suddenly transformed the Apple II from
a gadget only hard-core hobbyists would want to something all
sorts of people could use. Few outsiders realized it, but in
strategic terms, Woz's invention of the disk controller was as
important to the company as his invention of the computer
itself."<8>
++++++++++++++++++++++++++++++++++++
NEXT INSTALLMENT: The Apple II Plus
++++++++++++++++++++++++++++++++++++
NOTES
<1> Gregg Williams and Rob Moore, "The Apple Story, Part 2: More
History And The Apple III", BYTE, Jan 1985, pp. 167-168.
<2> Paul Freiberger and Michael Swaine, "Fire In The Valley, Part Two
(Book Excerpt)", A+ MAGAZINE, Jan 1985, p. 45.
<3> Williams and Moore, "Part II", p. 168.
<4> Freiberger and Swaine, (Part Two), p. 45.
<5> Freiberger and Swaine, (Part Two), p. 46.
<6> -----, "A.P.P.L.E. Co-op Celebrates A Decade of Service",
CALL-A.P.P.L.E., Feb 1988, pp. 12-27.
<7> -----, "Apple and Apple II History", THE APPLE II GUIDE, Fall
1990, pp. 9-16.
<8> Frank Rose, WEST OF EDEN: THE END OF INNOCENCE AT APPLE COMPUTER,
1989, pp. 62.
APPLE II HISTORY
===== == =======
Compiled and written by Steven Weyhrich
(C) Copyright 1991, Zonker Software
(PART 6 -- THE APPLE II PLUS)
[v1.1 :: 12 Dec 91]
THE APPLE II PLUS: HARDWARE
We now go cruising ahead in time about one year, to June of 1979.
Applesoft BASIC had been in heavy demand since the introduction in late
1978 of an improved version. It was needed by those wanting to write and
use applications that needed the capability of floating-point math.
Because of this, Apple engineers had begun working in 1978 on the Apple II
Plus, a modest enhancement to the Apple II. The main attraction of this
newer Apple would be Applesoft in ROM, available immediately without having
to load it from cassette or disk. Also, having it in ROM would move it out
of the part of memory where RAM Applesoft conflicted with hi-res graphics
(after all, Applesoft had commands specifically written into it for
manipulating those graphics, something that Integer BASIC could only do via
special CALLs to the routines in the Programmer's Aid #1 chip).
With the decision made to upgrade the Apple II, other changes were
made to make it more attractive to new computer buyers. The cost of RAM
chips had dropped considerably, so most new II Plus systems came standard
with a full 48K of RAM. Since the disk operating system consumed about 10K
of memory, having the full complement of available RAM made it easier to
use the Disk II with either version of BASIC. Since users would not need
to add the smaller 4K memory chips, the strapping blocks that had made it
possible to use either 4K or 16K RAM chips on the original Apple II were
removed.
Small changes had already been made to the product since it first
began distribution. Most of these changes were made primarily to simplify
it and decrease costs of manufacturing. First of all, the original
Apple II motherboard, designated as "Revision 0", was changed to make it
possible to display two more colors in hi-res graphics. The Revision 0
board had only four colors (green, violet, black, white), but Wozniak had
learned that by making a simple alteration he could get two more colors
(blue and orange) and two more varieties of black and white. The
Revision 1 and later boards were capable of displaying all eight colors.
The means of making this modification to Revision 0 Apples was described by
Wozniak in his reply to an article by Allen Watson III about hi-res
graphics (in the June 1979 issue of Byte magazine). With that change,
people who were not afraid of doing a little electrical work on their
computers had some of the benefits of an updated Apple II.
Hardware bugs that Apple engineers fixed included one that caused
text characters to be displayed with green and violet fringing, whether in
graphics mode or text mode. The "color killer" circuit they added fixed
things so that non-graphics text would display in black and white only.
Another problem involved RAM configurations of either 20K or 24K (a 16K RAM
chip plus one or two 4K RAM chips). In those systems a hardware bug caused
the 8K of memory from $4000 to $5FFF to be duplicated in the next 8K of
memory, from $6000 to $7FFF, whether there was RAM present at those
locations or not. This made a 20K Apple appear to have 24K, and a 24K
Apple appear to have 36K. The Revision 1 motherboard fixed this problem as
well.<1>
Revision 1 boards also modified the cassette input circuit to respond
with more accuracy to a weak input signal, making it easier to load data
and programs from cassette. Also, one "feature" of the original Apple II
was that any sound generated by the internal speaker also appeared as a
signal on the cassette output connector; this was fixed in the new
motherboards. Lastly, the RESET cycle was made part of the power-up
circuitry, eliminating the requirement that the RESET key be pressed after
turning on the computer.<2>,<3>
THE APPLE II PLUS: FIRMWARE
More important than the minor hardware changes, however, were the
changes in the ROM code. The new ROM replaced the original Monitor with
one that, among other things, better supported the new Disk II drive.
Since RESET was now automatically activated when the power was turned on,
the new ROM code had the computer automatically do a few things. It
cleared the screen (displaying "APPLE ][" at the top), and began a scan
down the slots, starting at slot 7 down to slot 1. It examined the first
few bytes of code in each card's ROM for a specific sequence that
identified it as a Disk II controller card. If one was found, control was
passed to that card, causing the disk drive to startup and begin loading
the disk operating system into memory. If no disk controller was found,
the ROM code jumped instead to the start of BASIC (instead of leaving the
user in the Monitor, as in the old ROM). This "Autostart ROM", as it was
called, made it possible to have a system that started up a program on the
disk with little action needed by the user.
The RESET code was more intelligent in the Autostart ROM than in the
Old Monitor ROM. There was now a "Cold Start" RESET (which functioned as
described above), and a "Warm Start" RESET. A Warm Start RESET could occur
without re-booting the Disk II (if it was present); in fact, it ensured
that the disk operating system remained "connected" after RESET was
pressed. This feature was implemented by setting three bytes at the end of
page $03 in memory. Two of the bytes were the address of the place in
memory to which the Apple should jump if RESET was pressed. The third byte
was a specially coded byte created from half of the address byte. When
RESET was pressed, this special "power-up" byte was checked with the
address byte. If they didn't properly match, the Monitor assumed that the
power had just been turned on, and it executed a Cold Start RESET. This
feature was extensively used by writers of copy protected software, so
users could not modify or copy the code in memory simply by pressing the
RESET key.
The other major change, mentioned earlier, was the BASIC that was
supplied in ROM. Gone was Steve Wozniak's hand-assembled Integer BASIC, in
favor of the newer Applesoft. Since these ROM versions of BASIC used the
same memory locations, they could not be used simultaneously. With the
introduction of the II Plus, Apple also released the Applesoft Firmware
card. This card, which plugged into slot 0, made it possible for previous
Apple II owners to have some of the benefits of the II Plus without having
to buy an entirely new computer. Even with that card, however, you could
not use features of one BASIC while the other was active, and switching
from one BASIC to the other erased any program that was being used at the
time. The two BASICs could be told apart by the prompt they used; Integer
BASIC used the ">" character, but Applesoft used the "]" character.
Another change made to the Monitor ROM made screen editing easier.
The original Apple II's procedure for editing a line typed in BASIC or in
the Monitor was tedious at best. To change a line of text in BASIC, you
had to list the line, move the cursor up to the start of the line, and then
use the right-arrow key to "copy" text from the screen into the input
buffer. If you wanted to skip part of the line, you had to move the cursor
past the text that you wanted to eliminate WITHOUT using the arrow keys.
If you wanted to INSERT something into the line, you had to move the cursor
off the line (above it or below it), type the additional text, and then
move the cursor back into the line to finish copying the original part of
the line.
For example, suppose you had typed this line in Applesoft and
displayed it on the 40-column screen:
]LIST 100
100 FOR I = 1 TO 100: PRINT "I
LIKE MY APPLE": NEXT : END
To change that line so the PRINT statement read "I REALLY LIKE MY
APPLE" meant either retyping the entire line, or using the edit feature.
(If the line was particularly long, it was preferable to edit rather than
retype the entire line). To edit this line, you would have to move the
cursor up to the "1" of "100" and begin pressing the right arrow key. When
you got to the "L" of "LIKE" you would have to move the cursor above or
below the line, type the word "REALLY" followed by a space, then move the
cursor back to the "L" of "LIKE", and continue copying with the right arrow
key. After editing a line, the screen might look like this:
100 FOR I = 1 TO 100: PRINT "I
LIKE MY APPLE": NEXT : END
REALLY
(In this example, I moved the cursor down one line, typed "REALLY",
and then moved it back to the start of the word "LIKE"). If you didn't
make any mistakes it would read like this:
]LIST 100
100 FOR I = 1 TO 100: PRINT "I
REALLY LIKE MY APPLE" : NEXT
: END
However, if you didn't take care to skip over the extra spaces
inserted in front of the word "LIKE" by the Applesoft LIST command, it
could appear this way:
100 FOR I = 1 TO 100: PRINT "I
REALLY LIKE MY APPLE"
: NEXT : END
The big problem with these cursor moves for editing under the Old
Monitor was that each move required two keypresses. To move the cursor up,
you had to press "ESC" and then "D" EACH TIME you wanted to move the cursor
up. "ESC A" moved right, "ESC B" moved left, and "ESC C" moved the cursor
down. With a long line that needed much editing, this would get old real
fast. Not only was it cumbersome, but the layout of the keyboard made it
difficult to remember the correct letters used for cursor movement;
although "D" (up) was above "C" (down), it seemed that "D" should stand for
"Down". Also confusing was that "A" was to the left of "B", but their
functions were the opposite of their position!
The new Autostart ROM improved this screen editing process just a
bit. Now, pressing "ESC" turned on a special editing mode. Repeated
presses of "I" (up), "J" (left), "K" (right), and "M" (down) continued to
move the cursor until a key other than ESC was pressed. On the keyboard
these letters were arranged in a sort of "directional keypad" or diamond,
which made remembering the moves a little easier. The previous ESC editing
codes were still supported, but still with their previous limitations.
Unfortunately, however, you still couldn't tell whether you were in the
regular text entry mode or in the ESC editing mode, and often attempts at
changing a line took several tries to get it right.<4>,<5>
Other features added in the new Autostart ROM included the ability to
pause a listing by pressing Ctrl-S (VERY helpful when trying to scan
through a long program!) As mentioned above, pressing RESET would return
control through the soft-entry vectors on memory page $03. This would
allow a user to exit from a runaway BASIC program by pressing RESET, and
still keep program and variables intact in memory (which could not be
guaranteed with the old Monitor ROM).<5>
John Arkley at Apple wrote the changes to the original Monitor ROM
and created the Autostart ROM in November 1978 (he's the "John A" mentioned
in the source code listing found in the 1981 edition of the APPLE II
REFERENCE MANUAL). After he had done the work and the ROMs had been
created, Apple wanted to publish a new version of the Reference Manual to
cover the Apple II Plus. The older Reference Manual (affectionately known
as the "Red Book") had included an assembly language source code listing of
the Monitor ROM. They wanted to include the source for BOTH versions of
the Monitor, but a problem came up. While developing the Monitor, Apple
had used a local mainframe computer dial-up service known as "Call
Computer." They used a cross-assembler on that computer, assembled the
code, and then used the resulting object code to create the ROM. (A
cross-assembler is an assembler that creates object code for a processor
other than the one the cross-assembler runs on. For example, if you can
write 8080 machine code with an assembler running on a 6502-based computer,
you are using a cross-assembler). Unfortunately, Call Computer had
accidentally done a system backup with the source and destination disks
reversed, erasing all the files containing the source code for the Apple II
Monitors. There were no disk or cassette copies of the source code for the
Autostart ROM back at Apple. Working from the source listing in the Red
Book, John recreated the source file for the original Monitor, and then
disassembled his own modifications for the II Plus and re-created his
Autostart ROM source file. Those reconstructed listings are what appeared
in the 1981 edition of the Apple II Reference Manual.<6>
Not everyone was pleased with the modifications made in the Autostart
ROMs, however. Some of the authors of the magazine CALL-A.P.P.L.E. liked
to refer to the new computer as the "Apple II Minus", since Arkley had to
remove some of their beloved routines from the ROMs to make room for the
new features. Missing from the Apple II Plus ROMs were Integer BASIC, the
miniassembler, and Woz's SWEET 16 interpreter (that entire space now being
used by Applesoft). Missing from the Monitor were the assembly language
STEP and TRACE features, and a set of sixteen-bit multiply and divide
routines.<5>
THE APPLE II PLUS: COST
The new Apple II Plus, at $1,195, sold for over $100 less than the
original Apple II, although it came with more memory and had Applesoft
(previously an added expense item) in ROM.
THE APPLE II PLUS: BELL & HOWELL
Apple made a deal early on with Bell & Howell to let them sell the
Apple II Plus with a Bell & Howell name plate on it for use in schools.
These Apples were black colored (instead of the standard beige), and had
screws on the back to keep the lids on (apparently to keep students' hands
out). These Apples (sometimes called "Darth Vader" Apples) also had the
"shift-key mod" (see below) applied. Since Bell & Howell was a major
supplier of school equipment, this was a means for Apple to get a foothold
in the school environment.<7>,<8>
Bell & Howell also had electronics correspondence courses, and used
the black Apple II Plus for one of their courses. They offered a one year
warranty, instead of the ninety-day warranty offered by Apple.<9>,<10>,<11>
THE APPLE II PLUS: EARLY USER EXPERIENCES
An Apple II veteran on GEnie, Dennis Ulm, kindly provided me with the
following reproduction of his ORIGINAL Apple II Plus packing list. It
gives a little picture of what early non-disk users had to work with:
APPLE II PLUS
PACKING LIST
This package should contain the following items:
item no. part number description
---- --- ----------- -----------
1 1 600-2023 cassette tape: LITTLE BRICKOUT, COLOR DEMOSOFT
2 1 600-2024 cassette tape: RENUMBER/APPEND, ALIGNMENT TEST TONE
3 1 600-2025 cassette tape: FINANCE I, PENNY ARCADE
4 1 600-2026 cassette tape: LEMONADE, HOPALONG CASSIDY
5 1 600-2027 cassette tape: BRIAN'S THEME, PHONE LIST
6 1 030-2057 manual: Introductory Programs for the Apple II Plus
7 1 030-0044 manual: The Applesoft Tutorial
8 1 030-0013 manual: Applesoft II BASIC Programming Reference
Manual
9 1 030-0004 manual: Apple II Reference Manual
10 1 030-0035 publication: Apple Magazine
11 1 600-0033 1 pair of game controls
12 1 590-0002 cable: to hook up a cassette recorder
13 1 590-0003 cable: power cord for the Apple II Plus
14 1 030-0001 Apple Warranty Card
15 1 600-0816 Apple II Plus System 16K
or
600-0832 Apple II Plus System 32K
or
600-0848 Apple II Plus System 48K
(LITTLE BRICKOUT was an abbreviated Applesoft version of Woz's
Integer BASIC Breakout game (the reason he designed the Apple II in the
first place). BRIAN'S THEME was a hi-res graphics program that drew lines
on the screen in various patterns. HOPALONG CASSIDY was a "guess who"
program that also used the hi-res screen).<12>,<13>
Also included in Dennis' II Plus box was this photocopied instruction
sheet:
TAPE LOADING INSTRUCTIONS
If problems are encountered in LOADing tape programs, it
may be necessary to "queue" (sic) the tape before LOADing. To
queue a tape, use the following procedure:
1. Rewind the tape.
2. Disconnect the cable from the tape recorder (so you can
hear what's on the tape).
3. Start the tape recorder in PLAY mode.
4. When a steady tone is heard, STOP the tape recorder.
5. Connect the cable to the tape recorder and adjust the
volume and tone controls on the tape recorder to the
recommended levels.
6. Make sure your computer is in BASIC.
7. Type LOAD.
8. START the tape playing.
9. Press RETURN.
The program should LOAD properly. If an error message occurs,
repeat the procedure, but try readjusting the tone and volume
controls on the tape recorder.
Dennis says that in his experience it took at least five to ten tries
to get anything to load properly from tape!
THE APPLE II PLUS: MORE HARDWARE ADD-ONS
Lower-case was still not supported on the new Apple II Plus, though
it was a popular user-modification. The thriving industry for Apple II
peripherals made up for this shortcoming, with various vendors supplying
small plug-in circuit boards that fit under the keyboard, allowing display
of lower-case on the screen (and sometimes direct entry of lower-case from
the keyboard). By 1981, when the Revision 7 motherboard was released for
the Apple II Plus, a different method of character generation was used,
which reduced radio-frequency interference that was generated. For
Revision 7 boards, lower-case characters could be displayed with the
addition of only a single chip. However, unless a user changed the
keyboard encoder with a third-party product, only upper-case characters
could be typed.<14>
The keyboard itself underwent some changes, both by users and by
Apple. The original RESET key was in the upper right-hand corner of the
keyboard. The problem with that key was that it had the same feel as the
keys around it, making it possible to accidentally hit RESET and lose the
entire program that was being so carefully entered. One user modification
was to pop off the RESET keycap and put a rubber washer under it, making it
necessary to apply more pressure than usual to do a RESET. Apple fixed
this twice, once by replacing the spring under the keycap with a stiffer
one, and finally by making it necessary to press the CTRL key and the RESET
together to make a RESET cycle happen. The keyboards that had the
CTRL-RESET feature made it user selectable via a small slide switch just
inside the case (some people didn't want to have to press the CTRL key to
do a RESET).
Another keyboard limitation was addressed through a modification that
became known as the "shift-key mod". This was such a widely used trick
that Apple ended up supporting it in hardware when they designed the
Apple IIe. Since the II and II Plus keyboards could not directly generate
lower-case characters, early word processing programs had to find some way
to make up for that deficiency. Apple's own Apple Writer program used the
ESC key as a shift and shift-lock key, displaying upper-case characters in
inverse video and lower-case in regular video. Other programs suggested
installing the shift-key mod to allow more natural entry of upper-case,
using the SHIFT key already present on the keyboard. The user had to
attach a wire to the contact under the SHIFT key, and run it to the game
port where the input for push-button 2 was found. (This push-button PB2,
$C063 in memory, was for one of an optional second pair of game paddles
that third-party hardware companies supplied for the Apple II). The
program would assume that all letters being typed were in lower-case,
unless the SHIFT key (attached now to paddle button PB2) was also being
pressed; in that case the letter would be entered as upper-case. Since the
PB2 button was not often used for a second pair of game paddles, it was
unlikely that this modification would be accidentally triggered by pressing
one of the game paddle buttons. This modification did NOT use buttons PB0
or PB1, which were on the first pair of game paddles. (PB0 and PB1 now
correspond to the Open-Apple and Solid-Apple/Option keys on modern Apple II
computers).
++++++++++++++++++++++++++++++++
NEXT INSTALLMENT: The Apple IIe
++++++++++++++++++++++++++++++++
NOTES
<1> -----, "Memory Organization", APPLE II REFERENCE MANUAL, 1979,
1981, pp. 70-73.
<2> -----, APPLE II REFERENCE MANUAL, 1979,1981, pp. 25-27, 34-36.
<3> Bruce Field, "A.P.P.L.E. Doctor", CALL-A.P.P.L.E., Jan 1984, pp.
74-75.
<4> -----, "Apple and Apple II History", THE APPLE II GUIDE, Fall
1990, pp. 9-16.
<5> -----, APPLE II REFERENCE MANUAL, 1979,1981, pp. 25-27, 34-36.
<6> John Arkley, (personal telephone call), Sep 9, 1991.
<7> Joe Regan, GEnie A2 ROUNDTABLE, Category 2, Topic 16, Apr 1991.
<8> Dan Paymar, "Curing A Shiftless Apple", CALL-A.P.P.L.E., May
1982, pp. 63-64.
<9> Tom Vanderpool, GEnie A2 ROUNDTABLE, Category 2, Topic 16, Mar &
Aug 1991.
<10> Tom Zuchowski, GEnie A2 ROUNDTABLE, Category 2, Topic 16, Mar
1991.
<11> Steve Hirsch, GEnie A2 ROUNDTABLE, Category 2, Topic 16, Mar
1991.
<12> Dennis Ulm, GEnie A2 ROUNDTABLE, Category 2, Topic 16, Apr 1991.
<13> Wes Felty, GEnie. A2 ROUNDTABLE, Category 2, Topic 16, Apr 1991.
<14> Bruce Field, "A.P.P.L.E. Doctor", CALL-A.P.P.L.E., Jan 1984, pp.
74-75.
APPLE II HISTORY
===== == =======
Compiled and written by Steven Weyhrich
(C) Copyright 1992, Zonker Software
(PART 7 -- THE APPLE IIE)
[v1.1 :: 26 Jan 92]
PRELUDE: THE APPLE III PROJECT
As we continue our travels examining the history of the Apple II,
let's fine tune the time-machine card on our souped-up Apple II to
concentrate specifically on the next version of the II, the IIe. As
before, just accelerate the microprocessor speed to 88 MHz, and watch out
for the digital fire-trails! Destination: 1982.
Between the years 1979 and 1983, although no new versions of the
Apple II were released, it enjoyed a broad popularity and annually
increasing sales. The open architecture of the computer, with its fully
described hardware and firmware function via the Reference Manual, made it
appealing both to hardware and software hackers. Third-party companies
designed cards to plug into the internal slots, and their function varied
from making it possible to display and use 80-column text, to clocks and
cards allowing the Apple II to control a variety of external devices.
During this time there was also an explosion of new software written for
this easily expandable machine, from the realm of business (VisiCalc and
other spreadsheet clones), to utilities, to games of all types. Each month
a host of new products would be available for those who wanted to find more
things to do with their computer, and the Apple II was finding a place in
the home, the classroom, and the office.
At Apple Computer, Inc., however, the Apple II was not viewed with
the same degree of loyalty. By September 1979 the Apple II had continued
to be a sales leader. However, few at Apple believed that the II could
continue to be a best seller for more than another year or two. Since
Apple Computer, Inc. was a business, and not just a vehicle for selling the
Apple II computer, they began to enlarge the engineering department to
begin designing new products.<1> These new design efforts had begun as far
back as late 1978. Their first effort was an enhanced Apple II that used
some custom chips, but that project was never finished. They also began
work on a different, more powerful computer that would use several
identical microprocessor chips sharing tasks. The main advantage would be
speed, and the ability to do high precision calculations. This computer
was code-named Lisa, and because it was such a revolutionary type of
design, they knew it would take many years to come to actual production.
Because of the power it was to have, Apple executives felt that Lisa was
the future of the company.<2>,<14>
Because they knew that the Lisa project would take a long time to
complete, and because the Apple II was perceived to have only a short
remaining useful life as a product, they began a new computer project
called the Apple III. Instead of building upon the Apple II as a basis for
this new computer, they decided to start from scratch. Also, although
Wozniak made most of the design decisions for the II, a committee at Apple
decided what capabilities the Apple III should have. They decided that the
Apple III was to be a business machine, and not have the home or
arcade-game reputation that the II had. It was to have a full
upper/lowercase keyboard and display, 80-column text, and a more
comprehensive operating system. They also decided that since it would be a
while before many application programs would be available for this new
computer, it should be capable of running existing Apple II software. In
some ways this handicapped the project, since it was then necessary to use
the same microprocessor and disk drive hardware as was used in the
Apple II.<3>
Apple executives also decided that with the introduction of the
Apple III they wanted a clear separation between it and the Apple II in
regards to marketing. They did not want ANY overlap between the two. The
III would be an 80-column business machine and was predicted to have ninety
percent of the market, while the Apple II would be a 40-column home and
school machine and would have ten percent of the market. Apple's
executives were confident that after the release of the Apple III, the
Apple II would quickly lose its appeal.<4>
Because of their desire for a strong and distinct product separation,
the Apple II emulation mode designed into the Apple III was very limited.
The engineers actually ADDED hardware chips that prevented access to the
III's more advanced features from Apple II emulation mode. Apple II
emulation couldn't use 80 columns, and had access to only 48K memory and
none of the better graphics modes. As a result, it wouldn't run some of
the better Apple II business software, during a time when there wasn't much
NEW business software for the Apple III.
The Apple III engineers were given a one year target date for
completion. It was ready for release in the spring of 1980, but there were
problems with both design and manufacturing. (It was the first time that
Apple as a company tried to come out with a new product; the Apple II had
been designed and built by Wozniak when he WAS the engineering department).
The first Apple III computers were plagued with nearly 100% defects and had
to be recalled for fixes. Although Apple took the unprecedented step of
repairing all of the defective computers at no charge, they never recovered
the momentum they lost with that first misstep, and the III did not become
the success Apple needed it to be.<3>
Although all of the bugs and limitations of the Apple III were
eventually overcome, and it became the computer of choice within Apple, it
did not capture the market as they had hoped. At that point, they weren't
sure exactly what to do with the II. They had purposely ignored and
downplayed it for the four years since the II Plus was released, although
without its continued strong sales they would not have lasted as a company.
In a 1985 interview in Byte magazine, Steve Wozniak stated:
"When we came out with the Apple III, the engineering staff
cancelled every Apple II engineering program that was ongoing, in
expectation of the Apple III's success. Every single one was
cancelled. We really perceived that the Apple II would not last
six months. So the company was almost all Apple III people, and
we worked for years after that to try and tell the world how good
the Apple III was, because we KNEW [how good it was] ... If you
looked at our advertising and R&D dollars, everything we did here
was done first on the III, if it was business related. Then
maybe we'd consider doing a sub-version on the II. To make sure
there was a good boundary between the two machines, anything done
on the II had to be done at a lower level than on the III. Only
now are we discovering that good solutions can be implemented on
the II ... We made sure the Apple II was not allowed to have a
hard disk or more than 128K of memory. At a time when outside
companies had very usable schemes for adding up to a megabyte of
memory, we came out with a method of adding 64K to an Apple IIe,
which was more difficult to use and somewhat limited. We refused
to acknowledge any of the good 80-column cards that were in the
outside world--only ours, which had a lot of problems."<4>
Wozniak went on in that interview to say that at one time he had
written some fast disk routines for the Pascal system on the Apple II, and
was criticized by the Apple III engineers. They didn't think that anything
on the II should be allowed to run faster than on a III. That was the
mindset of the entire company at the time.
Apple has been much maligned for the attention they gave the
Apple III project, while suspending all further development on the
Apple II. They pegged their chances for the business market in 1980 on the
Apple III. Even Steve Wozniak had stated in another interview, "We'd have
sold tons of [computers in the business market] if we'd have let the II
evolve ... to become a business machine called the III instead of
developing a separate, incompatible computer. We could have added the
accessories to make it do the business functions that the outside world is
going to IBM for."<3> Part of the problem was the immaturity of the entire
microcomputer industry at the time. There had NEVER been a microcomputer
that had sold well for more than a couple of years before it was replaced
by a more powerful model, usually from another company. The Altair 8800
and IMSAI had fallen to the more popular and easier to use Apple II and
TRS-80 and Commodore PET, as well as other new machines based on the Intel
8080 and 8088 processors. It is entirely understandable that Apple's
attitude between 1978 and 1980 would be of panic and fear that they
wouldn't get a new computer out in time to keep their market share and
survive as a company. However, during the entire time when Apple was
working on the III as a computer to carry the company through until Lisa
would be ready, and during the entire time that the Apple II was ignored by
its own company, it continued to quietly climb in sales. It is a credit to
both the ingenuity of Wozniak in his original design, and to the users of
the Apple II in THEIR ingenuity at finding new uses for the II, that its
value increased and stimulated yet more new sales. The Apple II "beat" the
odds of survival that historically were against it.
THE APPLE IIE: BEGINNINGS
When Apple saw that the sales on the Apple II were NOT going to
dwindle away, they finally decided to take another look at it. The first
new look at advancing the design of the II was with a project called
"Diana" in 1980. Diana was intended primarily to be an Apple II that had
fewer internal components, and would be less expensive to build. The
project was later known as "LCA", which stood for "Low Cost Apple". Inside
Apple this meant a lower cost of manufacturing, but outsiders who got wind
of the project thought it meant a $350 Apple II. Because of that
misconception, the final code name for the updated Apple II was "Super II",
and lasted until its release.<5>
THE APPLE IIE: HARDWARE
Part of the IIe project grew out of the earlier work on custom
integrated circuits for the Apple II. When they finally decided to go
ahead and improve the design by adding new features, one of the original
plans was to give the Apple II an 80-column text display and a full
upper/lowercase keyboard. Walt Broedner at Apple did much of the original
hardware planning, and was one of those at Apple who pushed for the upgrade
in the first place. To help maintain compatibility with older 40-column
software (which often addressed the screen directly for speed), he decided
to make 80-columns work by mirroring the older 40 column text screen onto a
1K memory space parallel to it, with the even columns in main memory and
the odd columns in this new "auxiliary" memory. To display 80-column text
would require switching between the two memory banks. Broedner realized
that with little extra effort he could do the same for the entire 64K
memory space and get 128K of bank-switchable memory. They put this extra
memory (the 1K "80-column card, or a 64K "extended 80-column card") in a
special slot called the "auxiliary" slot that replaced slot 0 (the 16K
Language Card was going to be a built-in feature). The 80-column firmware
routines were mapped to slot 3, since that was a location commonly used by
people who bought 80-column cards for their Apple II's, and was also the
place where the Apple Pascal system expected to find an external terminal.
The auxiliary slot also supplied some special video signals, and was used
during manufacture for testing on the motherboard.
The engineers that worked on the IIe tried hard to make sure that
cards designed for the II and II Plus would work properly in the new
computer. They even had to "tune" the timing on the IIe to be slightly OFF
(to act more like the II Plus) because the Microsoft CP/M Softcard refused
to function properly with the new hardware. A socket was included on the
motherboard for attaching a numeric keypad, a feature that many business
users had been adding (with difficulty) to the II Plus for years. The full
keyboard they designed was very similar to the one found on the Apple III,
including two unique keys that had first appeared with the III--one with a
picture of an hollow apple ("open-apple") and the other with the same apple
picture filled in ("solid-apple"). These keys were electrically connected
to buttons 0 and 1 on the Apple paddles or joystick. They were available
to software designers as modifier keys when pressed with another key; for
example, open-apple-H could be programmed to call up a "help" screen. The
newer electronics of the keyboard also made it easier to manufacture
foreign language versions of the Apple IIe.<6>
Overall, Broedner and Peter Quinn (the design manager for the IIe and
later the IIc projects) and their team managed to decrease the number of
components on the motherboard from over one hundred to thirty-one, while
adding to the capabilities of the computer by the equivalent of another
hundred components.
THE APPLE IIE: FIRMWARE
Peter Quinn had to beg for someone to help write the firmware
revisions to the Monitor and Applesoft for the IIe. He finally got Rich
Auricchio, who had been a hacker on the Apple II almost from the beginning.
Quinn said in a later interview, "You cannot get someone to write firmware
for this machine unless he's been around for three or four years. You have
to know how to get through the mine field [of unofficial but commonly used
entry points]. He [Rick] was extremely good. He added in all the
80-column and Escape-key stuff." Quinn also got Bryan Stearns to work on
the new Monitor.<6>,<7>
Changes were made in the ROMs to support the new bank-switching modes
made necessary by having two parallel 64K banks of RAM memory. To have
enough firmware space for these extra features, the engineers increased the
size of the available ROM by making IT bank-switched. This space was taken
from a location that had previously not been duplicated before--the memory
locations used by cards in the slots on the motherboard. Ordinarily, if
you use the Monitor to look at the slot 1 memory locations from $C100
through $C1FF, you get either random numbers (if the slot is empty), or the
bytes that made up the controller program on that card. Any card could
also have the space from $C800 through $CFFF available for extra ROM code
if they needed it. If a card in a slot did a read or write to memory
location $CFFF, the $C800-$CFFF ROM that belonged to that card would appear
in that space in the Apple II memory. When another card was working, then
ITS version of that space would appear. On the IIe, they made a special
soft-switch that would switch OUT all the peripheral cards from the memory,
and switch IN the new expanded ROM on the motherboard. The firmware in the
new bank-switched ROM space was designed to avoid being needed by any card
in a slot (to avoid conflicts), and much of it was dedicated to making the
80-column display (mapped to slot 3) work properly.
Also added were enhancements to the ESC routines used to do screen
editing. In addition to the original ESC A, B, C, and D, and the ESC I, J,
K, and M added with the Apple II Plus, Auricchio added the ability to make
the ESC cursor moves work with the left and right arrow keys, and the new
up and down arrow keys. The new IIe ROM also included a self-test that was
activated by pressing both apple keys, the control key, and RESET
simultaneously.<5>
THE APPLE IIE: SUCCESS
The new Apple IIe turned out to be quite profitable for Apple. Not
only was it more functional than the II Plus for a similar price, but the
cost to the dealers selling it was about three times the cost of
manufacture. They had gotten their "Low Cost Apple", and by May of 1983
the Apple IIe was selling sixty to seventy thousand units a month, over
twice the average sales of the II Plus. Christmas of 1983 saw the IIe
continue to sell extremely well, partly resulting from the delayed
availability of the new IBM PCjr. Even after the Apple IIc was released in
1984, IIe sales continued beyond those of the IIc, despite the IIc's
built-in features.<8>
THE APPLE IIE: MODIFICATIONS
Early Apple IIe motherboard's were labelled as "Revision A".
Engineers determined soon after its introduction that if the same use of
parallel memory was applied to the hi-res graphics display as was done with
the text display, they could create higher density graphics. These
graphics, which they called "double hi-res", also had the capability of
displaying a wider range of colors, similar to those available with the
original Apple II lo-res graphics. The IIe motherboards with the necessary
modifications to display these double hi-res graphics were labelled
"Revision B", and a softswitch was assigned to turning on and off the new
graphics mode.
Later versions of the IIe motherboards were again called "Revision A"
(for some reason), although they HAD been modified for double hi-res
graphics. The difference between the two "Revision A" boards was that the
latter had most of the chips soldered to the motherboard. An original
"Revision A" board that had been changed to an Enhanced IIe was not
necessarily able to handle double hi-res, since the change to the Enhanced
version involved only a four-chip change to the motherboard, but not the
changes to make double hi-res possible.<9>
THE APPLE IIE: THE ENHANCED IIE
This version of the Apple IIe was introduced in March of 1985. It
involved changes to make the IIe more closely compatible with the Apple IIc
and II Plus. The upgrade consisted of four chips that were swapped in the
motherboard: The 65c02 processor, with more assembly language opcodes,
replaced the 6502; two more chips with Applesoft and Monitor ROM changes;
and the fourth a character generator ROM that included graphics characters
(first introduced on the IIc) called "MouseText". The Enhanced IIe ROM
changes fixed most of the known problems with the IIe 80-column firmware,
and made it possible to enter Applesoft and Monitor commands in lower-case.
The older 80-column routines were slower than most software developers
wanted, they disabled interrupts for too long a time, and there were
problems in making Applesoft work properly with the 80-column routines.
These problems were solved with the newer ROMs.
Monitor changes also included a return of the mini-assembler, absent
since the days of Integer BASIC. It was activated by entering a "!"
command in the Monitor, instead of a jump to a memory location as in the
older Apple ][. Also added were an "S" command was added to make it
possible to search memory for a byte sequence, and the ability to enter
ASCII characters directly into memory. However, the "L" command to
disassemble 6502 code still did not handle the new 65c02 opcodes as did the
IIc disassembler. Interrupt handling was also improved.
Applesoft was fixed to let commands such as GET, HTAB, TAB, SPC, and
comma tabbing work properly in 80-column mode.
The new MouseText characters caused a problem for some older programs
at first, until they were upgraded; characters previously displayed as
inverse upper-case would sometimes display as MouseText instead.<10>,<11>
THE APPLE IIE: THE PLATINUM IIE
This version of the IIe, introduced in January 1987, had a keyboard
that was the same as the IIGS keyboard, but the RESET key was moved above
the ESC and "1" keys (as on the IIc), and the power light was above the "/"
on the included numeric keypad (the internal numeric keypad connector was
left in place). The CLEAR key on the keypad generated the same character
as the ESC key, but with a hardware modification it could generate a Ctrl-X
as it did on the IIGS. The motherboard had 64K RAM in only two chips
(instead of the previous eight), and one ROM chip instead of two. An
"extended 80-column card" with 64K extra memory was included in all units
sold, and was smaller than previous versions of that memory card.
No ROM changes were made. The old shift-key modification was
installed, making it possible for programs to determine if the shift-key
was being pressed. However, if using a game controller that actually used
the third push-button (where the shift-key mod was internally connected),
pressing shift and the third push-button simultaneously causes a short
circuit that shuts down the power supply.<12>
THE APPLE IIE: EMULATION CARD ON MACINTOSH LC
In early 1991, Apple introduced a new version of the Apple IIe. This
one was designed to be exactly like the 128K Platinum IIe, with the
modification that it had a color Macintosh attached to it. This Apple IIe
cost only $199, but the required Macintosh peripheral went for about
$2,495, which makes the combination the most expensive Apple II ever made.
Apple engineers managed to put the function of an entire IIe onto a card
smaller than the old Disk II controller card. With version 2.0 of the
Apple II interface software, more of the memory allocated to the Macintosh
could be used by the IIe (strange way of designing an Apple II!). However,
unlike all previous versions of the IIe, there were no hardware-based slots
on the IIe card; instead, it used software-based slots that were allocated
by moving icons that represent various peripherals into "slots" on the Mac
screen. (Oh, yes; it ran some Mac software, too. This was, of course, the
Macintosh LC computer with its optional Apple IIe card).
To use 5.25 disks with this Apple IIe, there was a cable that
attached to the card. The cable would split into a game connector (for
paddles or joystick operation) and a connector that accepted IIc and IIGS
style 5.25 drives. The IIe card ran at a "normal" (1 MHz) speed and a
"fast" (2 MHz) speed.<13> It had limitations, however. For a 1991
Apple II, it was limited in being unable to be accelerated beyond 2 MHz (a
Zip Chip can run a standard IIe at 8 MHz), and the screen response seemed
slow, since it was using a software-based Mac text display instead of the
hardware-based Apple II character ROM. As a Macintosh it lacked the power
and speed of the newer Macintosh II models (which also ran color displays).
But if having a Apple II and a Mac in one machine was important, this was
the best way to do it.
++++++++++++++++++++++++++++++++
NEXT INSTALLMENT: The Apple IIc
++++++++++++++++++++++++++++++++
NOTES
<1> Freiberger, Paul, and Swaine, Michael. "Fire In The Valley, Part
I (Book Excerpt)", A+ Magazine, Jan 1985, p. 45-48.
<2> Freiberger, Paul, and Swaine, Michael. "Fire In The Valley, Part
II (Book Excerpt)", A+ Magazine, Jan 1985, p. 46,51.
<3> Rubin, Charles. "The Life & Death & Life Of The Apple II",
Personal Computing, Feb 1985, p. 72.
<4> Williams, Gregg, and Moore, Rob. "The Apple Story, Part 2: More
History And The Apple III", Byte, Jan 1985, pp. 177-178.
<5> Tommervik, Al. "Apple IIe: The Difference", Softalk, Feb 1983,
pp. 118-127, 142.
<6> Williams, Gregg. "'C' Is For Crunch", Byte, Dec 1984, pp.
A75-A78, A121.
<7> Little, Gary. Inside The Apple //c, 1985, pp. 1-7.
<8> Rose, Frank. West Of Eden: The End Of Innocence At Apple
Computer, 1989, pp. 98-99.
<9> Weishaar, Tom. "Ask Uncle DOS", Open-Apple, Dec 1986, p. 2.86.
<10> Weishaar, Tom. "A Song Continued", Open-Apple, Mar 1985, pp.
1.20-1.21.
<11> Weishaar, Tom. "Demoralized Apple II Division Announces
Enhanced IIe...", Open-Apple, Apr 1985, pp. 1.25-1.27.
<12> Weishaar, Tom. "Apple Introduces An Updated IIe", Open-Apple,
Jan 1987, p. 3.1.
<13> Doms, Dennis. "The Apple II as Mac peripheral", Open-Apple,
Jul 1991, pp. 7.43-7.44.
<14> This was an early version of the Lisa project. When the 68000
microprocessor became available from Motorola, it was decided to
use that as a single processor for the Lisa. Also, after Steve
Jobs paid a visit to the Xerox lab and saw the Xerox Star
computer with its icon interface and mouse pointing device, he
pushed strongly for the Lisa to work in that way.
APPLE II HISTORY
===== == =======
Compiled and written by Steven Weyhrich
(C) Copyright 1992, Zonker Software
(PART 8 -- THE APPLE IIC)
[v1.1 :: 12 May 92]
PRELUDE: STEVE JOBS AND MACINTOSH
Rewind back to 1982, before the Apple IIe was introduced, and adjust
the tuning on our Flux Capacitor-enhanced peripheral card. Before dealing
specifically with the smallest Apple II, the IIc, it would help to take an
aside and look at some other events happening at Apple Computers, Inc. at
this time that affected its development.
If you recall, the Lisa project was designated as the computer that was
considered to be the future of Apple. From a series of parallel processors
and a "bit slicing" architecture, to a focus on the Motorola 68000
microprocessor as the controller of this advanced computer, the project had
been progressing very slowly. It was begun back in 1979 with the same focus
as any other Apple product: "Both [Apple III and Lisa] had been conceived of
as nifty pieces of hardware rather than as products to appeal to a specific
market: At Apple you designed a box and people bought it because it was
neat, not because any thought had been given to what it would do for
them."<1> However, a significant change occurred in 1979 when Xerox bought a
large chunk of Apple stock. In return for being allowed this stock purchase,
Xerox allowed some of their research ideas to be used in designing an office
computer. After Steve Jobs visited the Xerox Palo Alto Research Center in
1979 and saw the user-interface on their Alto computer--icons, graphics-based
text characters, overlapping windows, and a pointing device called a
"mouse"--the Lisa took on a distinct personality that made it possible to
become the ultra-computer Apple needed. This was important, since by 1981
Apple executives were getting sweaty palms worrying about the future. The
Apple III was clearly NOT taking the business world by storm.
Unfortunately for Jobs, who was excited about using the Xerox
technology in designing a new computer, he was excluded from the Lisa
project. After the problems associated with the introduction of the
Apple III, a reorganization in 1980 moved the Apple II and III into one
division, and the Lisa into another. Lisa was put under the control of John
Couch, and Jobs was not allowed to participate. Since Lisa had been taken
away, Jobs in 1981 began to assemble a team to "out-Lisa the Lisa" by
creating a smaller, less expensive computer that would do the same thing.
Jef Raskin, the engineer that helped design it, called it Macintosh.
While the Macintosh developed as a pirate project with a smaller team
and less money than Lisa, the concept of an "appliance" computer also
emerged. Instead of those messy slots and a lid that popped off (which made
the Apple II so popular with the hacker community), Jobs' team was sold on
the idea that all necessary features should simply be built-in and the case
sealed. It would be something that you just plugged in, turned on, and
started using. With the Xerox Alto mouse/icon/window interface it would not
only be easy to set up and turn on, but also easy to use.
THE APPLE IIC: BEGINNINGS
What was happening with the Apple II during this time? The efforts to
make it less expensive to build were progressing, and the Apple IIe was in
the formative stages. In the summer of 1981 someone proposed a portable
Apple II, a book-sized computer. It wasn't until Steve Jobs became
interested in it as engineering challenge, well after Macintosh was under
way, that anything came of the idea:
"...one day late in '82, Paul Dali showed him [Jobs] a photograph of a
Toshiba portable and they started fooling around with the idea of an
Apple II that would look like the Toshiba but come with a built-in disk
drive. They took out a IIe circuit board and a disk drive and a
keyboard and played with them until they arrived at a promising
configuration--keyboard in front, disk drive in back, circuit board in
between. What got Jobs excited about this idea was the engineering
difficulty of squeezing it all into a package not much bigger than a
notebook. And a machine so small wouldn't have the expandability that
characterized all the other II's. Like Macintosh, it could be taken out
of the box, plugged in, and put to work--no extra parts to buy, no
cables to figure out. It was the II reinvented as an appliance."<2>
As with all Apple projects, the IIc went by various code names during
its development, for the sake of internal communications and to keep
outsiders from knowing what was going on. The various names used included
VLC (Very Low Cost), Yoda, ET, IIb (for "Book"), and Teddy (which stood for
"Testing Every Day"). Also, following a long standing tradition at Apple,
some of the code names assigned to the project at various times were names of
children of people at Apple: Chels, Jason, Lolly, Sherry, and Zelda. These
names persist in the source code for the firmware for the IIc as later
printed in the technical reference manual; the serial port driver is called a
"Lolly" driver.<3>
During the time the IIc was under development, Apple was working on a
change in the look of their products. They planned a more European styling,
and a color scheme called "Snow White". The IIc would be the first product
with the new appearance and color.
THE APPLE IIC: HARDWARE
As mentioned earlier, the IIc had its origins while the IIe project was
going on. When Steve Jobs became involved, he felt they should continue with
the open IIe as they had planned, but do this other Apple II as a product
"focused" to a specific group of customers, primarily new users. Originally
he had planned a closed Apple II that had a built-in mouse port, one serial
port, and some other features. What they ended up with at that point was
just a computer and a keyboard. Walt Broedner, the engineer who pushed for
the Apple IIe to be produced, used some of their previous work with custom
IC's for the disk controller and combined both projects together to make the
IIc.<4>
Although he was told it was not be possible, Jobs strongly pushed for
the mouse in this closed Apple II to be compatible with the Macintosh
mouse--and they managed to make it work.<2> Regarding the plans for a single
serial port, however, Apple's marketing people pointed out to Jobs that many
people were going to want both a printer AND a modem, so they added a second
port to the original design. They decided to use serial ports on the IIc
instead of parallel ports for a couple of reasons. First, the socket for a
serial port is smaller than a parallel port, and it would fit better onto a
small box like the IIc. Also, Apple's general direction at the time was to
get consistency in its hardware, and they had decided to make everything they
made use a serial interface.<4>
They began work on the Apple IIc in earnest right after the IIe was
finished. Because they were trying to squeeze an Apple IIe with 128K, 80
column routines, two serial cards, disk controller, and a mouse card into an
11 by 12-inch case, the design challenges were greater than with the IIe
(recall that this was what appealed to Steve Jobs). The size of the case was
determined by the decision to make it able to fit into a standard-sized
briefcase.<4>
Apple also had the international market in mind when they designed the
IIc. A special chip containing the keyboard map could easily be changed
depending on the country where the computer would be sold, to make it
consistent with regional keyboard differences. The external pushbutton would
switch between the two different keyboards, between a UK and German layout,
for example. In the U.S. version of the IIc it switched from a standard
Sholes keyboard (also known as "QWERTY") to a Dvorak keyboard (which allows
faster touch typing). The decision for the foreign keyboards came first; the
added bonus for American versions of getting Dvorak came as an extra bonus,
to save having two different cases (one for US and one for foreign
versions).<4>
One problem in creating such a compact computer was dealing with heat
production. Apple engineers wanted it to be able to function in
environmental temperatures up to 40 degrees Celsius (about 104 degrees
Fahrenheit). One article published at the time of its introduction mentioned
jokingly that the designers wanted to make the IIc capable of doing a long
disk sort (sorting data in a disk file) while on the beach in Florida in the
summer! Their major obstacle was the heat generated by the internal 5.25
disk drive. They tried some special low power drives (which would have been
much more expensive), but they didn't overcome the heat problem even with
them. Eventually they tried a complicated venting scheme that was designed
by drilling holes into a case and putting it into an oven to let them measure
internal temperatures. The engineers were surprised when they found that the
normal power disk drive worked and generated less overall heat within the
case than the special low power drive did. The only explanation they could
come up with was that the normal power drive generated enough heat to cause
it to rise, which pulled cool air in through the vents by convection.<4>
THE APPLE IIC: FIRMWARE
Since they used the newer 65c02 chip, which ran cooler and had 27
additional commands that could be used by assembly language programs, Apple's
programmers had some new power to use in firmware design. Such power was
needed to squeeze in all the firmware code for the IIe, plus code for the
disk controller, serial cards, mouse card, and 80 column card into 16K of ROM
space.
The firmware for the IIc was written by Ernie Beernink, Rich Williams,
and James Huston. They designed it to look (to a software application
program) exactly like a IIe with an Apple Super Serial Card in slots 1 and 2,
an 80-column card in slot 3, a mouse in slot 4, and a Disk II in slot 6
(though there were NO slots in hardware). Since these first IIc's had
nothing emulated in slot 5, the firmware authors immortalized themselves by
making a "ghost" peripheral appear to be present in that slot. Entering this
Applesoft program:
100 IN#5 : INPUT A$ : PRINT A$
and running it would print the names of the authors. (They used a decoding
scheme to extract the names, character by character, so a simple ASCII scan
of the ROM would not show their little trick). This "feature" had to be
removed in later revisions of the IIc ROM, because an actual disk device was
added then to slot 5.<4>,<5>
What about the unassigned slot 7? Here they put a small piece of code
to allow booting from the external 5.25 drive by typing "PR#7" from
Applesoft.
The programmers fixed some known bugs in the IIe ROMs, and added 32
graphics characters they called MouseText. To make MouseText fit they
removed the ability to use flashing characters (when in 80 column mode) and
replaced those characters with MouseText. Apple veteran Bruce Tognazzini
designed the MouseText characters, which included a picture of a running man
(perhaps to suggest "running" a program). He later sent a letter to
Call-A.P.P.L.E. magazine to warn programmers that the Running Man characters
(assigned to "F" and "G") had been determined to be unnecessary and would
probably be replaced eventually. (This did eventually happen, but not with
the IIc).
Beernick, Williams, and Huston also made some minor changes to the
Applesoft part of the ROM. They fixed things so Applesoft commands could be
entered in lowercase (and translated into uppercase). They removed the
Applesoft commands that were specific to the obsolete cassette interface
(which was absent in the IIc) and made Applesoft more compatible with 80
columns.<4>,<6> They did NOT go so far as to make any major changes in
Applesoft to use the newer 65c02 commands and therefore fix known bugs or add
features to this seven year old language. Their reluctance stemmed from the
fact that historically many BASIC programs had made use of undocumented
assembly language entry points in Applesoft, and any changes they would make
here made it more likely that older programs would crash unexpectedly.<4>
THE APPLE IIC: PRODUCT INTRODUCTION
Apple's introduction of the new IIc came at an "event" at the Moscone
Center in downtown San Francisco on April 24th, 1984. It was entitled
"Apple II Forever", and was described as "part revival meeting, part sermon,
part roundtable discussion, part pagan rite, and part county fair". Apple's
objectives here were to introduce the Apple IIc, describe how it fit into the
company's marketing strategy, show off new software that was made to work
with the new computer, and emphasize that Apple was still firmly behind the
Apple II line of computers. (Steve Jobs also took some of the time to report
on the sales of the Macintosh in its first 100 days).<7>
One of the interesting things they did at the "Apple II Forever" event
was the actual introduction of the IIc. Giant video screens were used to
show previews of Apple's TV commercials for the IIc, as well as slides and
images of the speakers, including Wozniak, Jobs, and Apple's new president,
John Sculley. Sculley spoke of "sharing power", and then demonstrated that
in a unique way: "After holding up the tiny IIc for everyone to see and
eliciting a response that they'd like to see it better, Sculley ordered the
house lights on. As the light burst forth, nearly every fifth person in the
audience stood up, waving high a IIc. As startled dealers cheered
uproariously, the Apple plants passed the IIcs to them. Within seconds of
its introduction, more than a thousand Apple dealers had a production-line
IIc in their hands."<7>
When Jobs gave his report on the Mac, it revealed some interesting
statistics. He told them that the first industry standard was the Apple II,
which sold fifty thousand machines in two and a half years. The second
standard was the IBM PC, which sold the same amount in eight months.
Macintosh had done sold its fifty thousand machines only 74 days after its
introduction. Although sales would not be nearly as good, Apple took orders
that day for fifty thousand Apple IIc's in just over seven HOURS.
At the "Apple II Forever" event, they also had a general software
exhibition and a setup called the Apple II Museum. This contained Apple
memorabilia, and included Woz's original Apple I, and a reproduction of Steve
Jobs' garage where it was built. Although not on the schedule, "Apple II
Forever" included an early-afternoon earthquake centered south of San Jose
that measured 6.2 on the Richter scale.
THE APPLE IIC: SUCCESS?
Their original goal had been to sell the IIc for $995. As productions
costs turned out, they found that they couldn't hit that price, so they came
up with $1,295, balancing the decision with the number of people who were
predicted to buy the optional Monitor IIc or an external Disk IIc drive.
The only problem was that although the IIc was a technological
breakthrough in miniaturization, customers at that time didn't value
smallness. They viewed something that was too small as also being cheap and
lacking power. Although the Apple IIc was equivalent to a IIe loaded with
extra memory, a disk drive, two serial cards, and a mouse card, most
customers seemed to want the more expandable IIe. Apple marketing went to
much effort to make the IIc attractive, but it didn't sell as well as the
IIe. Just as IBM overestimated the market when producing its PCjr (which
eventually failed and was discontinued), so did Apple when producing the IIc
(and the original Macintosh).<7>
THE APPLE IIC: OVERCOMING LIMITATIONS
Although the IIc did not have any slots for plugging in peripheral
cards that had traditionally been used in the Apple II, the ports that were
built-in had the capability to do much of what the slots had often been used
for. The serial ports were compatible with any serial device; this included
common ones such as printers and modems, and uncommon ones like security
controllers, clocks, and speech synthesizers. Some third party companies
also supplied serial-to-parallel converters for IIc owners who wanted to use
parallel printers made by Epson, Okidata, and C. Itoh that were popular
elsewhere in the computer world.
There was, of course, the AppleMouse IIc sold by Apple. It plugged
into the game port on the IIc. Also available were two types of touch
tablets: The Power Pad (Chalkboard) and Koala Pad (Koala Technologies),
though the latter sold best. The Koala pad would appear to a program to be
the same as a joystick, but could not emulate the mouse.<8>
The disk port on the original IIc was only designed to control an
external 5.25 disk drive. Apple sold the Disk IIc for $329, and other
companies later sold similar drives for less. Despite this firmware
limitation, Quark Engineering released a 10 MB Winchester hard drive called
the QC10 that would work with this disk port, and was the first hard disk
available for the IIc.<8>
The video port worked with a standard monitor, but had access to all
video signals. Included with the original IIc was an RF modulator that
allowed it to be connected to a standard television (for color games). An
RGB adapter box attached to the video port would allow a true RGB monitor to
be attached, giving color and sharp, readable 80 column text on the same
monitor. Apple also sold a flat-panel liquid crystal display for the IIc
that attached to this video port. It was capable of 80 columns by 24 lines,
as well as double hi-res graphics. Apple's price was about $600, but it
looked somewhat "squashed" vertically, and did not sell well. Another
company marketed a better flat panel liquid crystal display called the C-Vue.
With a battery attached to the 12V input, and a liquid crystal display,
the IIc could be made into a truly portable computer.<8>
THE APPLE IIC: ENHANCEMENTS
The earliest change made available for the IIc was a motherboard swap
that fixed a hardware bug causing some non-Apple modems to fail if used at
1200 baud. This modification was made only if the owner could show they
needed the change (that is, they owned a 1200 baud modem that wouldn't work).
The first significant upgrade available for Apple IIc owners was also
available as a free upgrade for previous owners. Changes were made to the
disk port firmware to accommodate the new 800K UniDisk 3.5. Using Apple's
Protocol Converter scheme (later called "Smartport"), this new IIc could
handle four 3.5 disk drives, or three 3.5 disk drives and one 5.25 drive.
With the UniDisk 3.5 upgrade, the internal 16K ROM was increased in
size to a 32K ROM that was bank-switched to make space for the extra code
necessary to implement the Smartport. Also added were additional serial port
commands to improve compatibility with the older Super Serial Card. The
Mini-Assembler, absent from the Apple II ROMs since the days of the original
Integer BASIC Apple II, was added back in, with support for the extra
commands provided by the newer 65c02 processor (the disassembler had always
supported those new commands). The STEP and TRACE Monitor commands made a
comeback, having also been a casualty of the 1979 Autostart ROM for the
Apple II Plus. Rudimentary firmware was also included to allowing the IIc
to be attached to an AppleTalk network (a message that said "AppleTalk
Offline" would appear if you typed "PR#7" from BASIC), but it was never
completed, and did not appear in future revisions of the IIc ROMs. Lastly,
the new IIc ROMs included a built-in diagnostic program to do limited
testing of the computer for internal failures, and had improved handling of
interrupts.<9>
The next Apple IIc upgrade was known as the Memory Expansion Apple IIc.
This came as a response to requests for the ability to add extra memory to
the IIc. Applied Engineering had already produced a Z-80 coprocessor for the
IIc (to allow access to CP/M software), and an expanded memory card, up to
1 MB, which would either act as a RAMdisk for ordinary ProDOS applications,
or as extra memory for the AppleWorks desktop (through a special patching
program). Seeing the popularity of this, Apple released this third version
of the IIc ROMs and motherboard, this time with a RAM expansion slot
included. The Apple IIc Memory Expansion Card could take up to 1 MB of RAM,
in 256K increments. The firmware in the new ROMs made it work as a RAMdisk
automatically recognized by ProDOS and following the Smartport protocol that
had been designed for the UniDisk 3.5. Apple even included code in the new
ROM to patch DOS 3.3 so it could be used as a RAMdisk with that system (400K
maximum size), and did the same with Pascal v1.3. Also, because this
firmware was in the motherboard ROM, ANY company could make memory cards to
attach to this version of the IIc.
Other changes made in this version of the IIc ROM included moving the
mouse firmware from slot 4 to slot 7, and putting the RAMdisk firmware into
slot 4. Also fixed was a bug that caused a write-protected 3.5 disk to be
incorrectly identified with early versions of the UniDisk 3.5.<9>,<10>
Since code as complex as ROM firmware rarely makes it out the door
without at least one bug, Apple had to make one final improvement to the IIc
ROM. The Revised Memory Expansion Apple IIc (ROM version 4) included changes
which made it easier to identify if no RAM chips had been installed on the
memory card. A problem with keyboard buffering was also fixed. Lastly, this
version of the ROM resolved an obscure bug in the slot 2 firmware that was
supposed to allow the IIc to function as a simple terminal (with a modem
attached to that port). The previous version of the IIc ROM had been
assembled with a couple of wrong addresses in the code, and the terminal mode
produced garbage. Few people used this feature, so it was not noticeable to
most users, and the corrected ROM chip was therefore not as quickly available
as the original Memory Expansion upgrade.
++++++++++++++++++++++++++++++++++++++++++++++++++++++
NEXT INSTALLMENT: Disk Evolution / The Apple IIc Plus
++++++++++++++++++++++++++++++++++++++++++++++++++++++
NOTES
<1> Rose, Frank. WEST OF EDEN: THE END OF INNOCENCE AT APPLE COMPUTER,
1989, p. 48.
<2> Rose, Frank. ibid, pp. 110-112.
<3> Hogan, Thom. "Apple: The First Ten Years", A+ MAGAZINE, Jan 1987,
p. 45.
<4> Williams, Gregg. "'C' Is For Crunch", BYTE, Dec 1984, pp. A75-A78,
A121.
<5> Little, Gary. INSIDE THE APPLE //C, 1985, pp. 1-7.
<6> Weishaar, Tom. "Miscellanea", OPEN-APPLE, Aug 1985, pp. 1.61.
<7> Durkee, David. "Marketalk Reviews", SOFTALK, Jun 1984, p. 120.
<8> Baum, Peter. "Expanding The Unexpandable IIc", SOFTALK, Jun 1984,
pp. 95-97.
<9> -----. "Preface: The Apple IIc Family", APPLE IIC TECHNICAL
REFERENCE MANUAL, 1984, 1986, pp. xxiii-xxv.
<10> -----. APPLE IIC MEMORY EXPANSION CARD OWNER'S GUIDE, 1986, pp.
2-4.
APPLE II HISTORY
===== == =======
Compiled and written by Steven Weyhrich
(C) Copyright 1992, Zonker Software
(PART 9 -- DISK EVOLUTION / THE APPLE IIC PLUS)
[v1.2 :: 21 May 92]
ADVANCES IN APPLE II DISK STORAGE
Since Steve Wozniak's Disk II floppy drive changed the Apple II from a
hobbyist toy to a serious home and business computer in the late 1970's, the
progress of disk storage has been slow for the Apple II series. In 1978, the
year the Disk II was released, Mike Scott (Apple's president) and Randy
Wigginton were asked at a user group meeting whether they were going to go to
the larger capacity eight-inch floppy drives (which had been around before
the 5.25 floppy drives). They answered that no, the Apple II was not going
in that direction, but felt it might get a hard disk by 1979 or 1980, and
possibly earlier than that a double sided, double density 5.25 disk with 500K
per disk.<1> Of course, this never did happen; as we saw in part 7 of this
historical overview, the Apple III project began to overtake the hearts and
minds of Apple executives by 1979, and anything newer, bigger, or better was
reserved for that machine. As a result, DOS 3.2 and 3.3 was hard-coded to
work specifically with the Disk II and its 143K of available storage, and
never enhanced to easily access larger capacity drives. (Later, when we
examine the evolution of Apple II DOS, we will see that it was possible from
the beginning for DOS 3.2 and 3.3 to access up to 400K per disk in its
catalog structure; however, the low-level disk access routines built-in to
DOS were ONLY for the Disk II).
So what changes DID occur in Apple II disk storage? Between 1978, when
Apple released their original Shugart 5.25 inch floppy drives, and 1984,
nothing much changed. Third party company produced patches that modified DOS
3.2 (and later DOS 3.3) to work with larger drives; from eight-inch floppy
drives to hard disks (a whole 10 megabytes for only $5,350 from Corvus!<2>)
to other various short-lived innovations, all made to try to end the "floppy
shuffle". (One of the more interesting ones put five floppy disks into a
cartridge, and through software made them appear to the computer as one large
disk drive). Eventually Apple decided that the aging Disk II mechanism
needed a face lift, and they introduced in the DuoDisk in May of 1984. This
was essentially two Disk II drives in a single cabinet, with a special
controller card. The drive mechanism was improved to better read half-tracks
on disks (which some copy-protected software used), and at $795 was priced to
be less expensive than buying two of the older Disk II drives with a
controller card.<3> The most important advantage of this new design was an
elimination of the "fried disk drive" problem that happened constantly with
the older design. The old Disk II controller had two connectors, one for
each Disk II drive that could be connected. The problem was the in the
design of the connector; like the game paddle plugs for the original Apple II
and II Plus, the plugs for the Disk II drives were simply a series of pins
that had to be properly aligned for the drive to function (similar to the
delicate pins on a computer chip). If you tried to attach the plug in such a
way as to accidentally shift the pins over by one, it would burn out the
motor on the disk drive, requiring a trip for repairs to the local Apple
dealer. The new DuoDisk design made connection of the disk mechanism to the
controller fool-proof.
With the release of the Apple IIc in April 1984 came an external
Disk II drive that was designed to plug into the new disk port in the back of
the IIc, and was the same color and design as the IIc case. The Disk IIc was
specific to the Apple IIc and could not be used with any older version
Apple II, since it used a new, unique connector. However, since it was more
expensive than a used Disk II drive, many users found out how to make a
conversion cable to connect the older drive to the disk port; some even went
the other direction and found ways to connect the new drive to the older
Disk II controller cards for the II Plus and IIe.
The next small evolutionary step in disk storage technology for the
Apple II was introduced in June 1985, with the release of the UniDisk 5.25.
This drive was designed with the same appearance as the DuoDisk, but was a
single 5.25 drive. It was also designed to allow one drive to be
"daisy-chained" to another (one disk could plug into the back of another,
forming a "chain"), instead of the older method of connecting each drive
separately to the disk controller card. Its beige color was designed to
match the original Apple IIe.<4>,<5>
The last version of the Disk II was called the Apple 5.25 drive. It
was identical to the UniDisk 5.25 drive, except for its case, which was
designed in the platinum color to match the Apple IIGS and the platinum IIe.
The connector it used allowed it to also be connected in a daisy-chain
fashion.<5>
NOW A WORD FROM OUR SPONSOR: BASICS OF DISK STORAGE
Let's diverge for a moment from discussing specific Apple disk products
and turn to a description on how the data are stored on a disk. There are
two important concepts that you need to understand to see why some methods of
data storage are "faster" than other methods. The first concept is the
physical data layout on the disk, and the second concept is the "logical"
data layout.
The physical layout of data on a disk is important to the hardware of
the disk drive. If the computer tells the disk drive to retrieve data from
the disk, it has to be able to tell the drive exactly WHERE on the disk
surface that data are stored. Most disk drives in use today (and when Steve
Wozniak designed the original Disk II) store data on disks that are round,
magnetically coated pieces of plastic that spin within a protective sleeve.
The older 5.25 inch and 8 inch disks were "floppy" disks because they used a
flexible protective sleeve (unlike the older yet but larger capacity "hard"
or fixed disks, which usually could not be removed). The newer 3.5 inch
disks are also made of the same magnetically coated plastic, but their
protective sleeve is a hard shell. Within its sleeve the thin plastic disk
spins around rapidly while the disk drive motor is on.
When a disk is formatted, certain addresses are written to the disk
surface in a pattern that is known to the program (the disk operating system)
used by the computer controlling the disk drive. Most computers divide the
disk surface up into concentric rings (called "tracks"), and each track is
divided up into segments called sectors or blocks. Each segment holds a
specific number of bytes of data; for the Apple II, this has been either 256
bytes (sectors on 5.25 disks) or 512 bytes (blocks on newer disk devices).
The number of sectors or blocks per track differs, depending on the device in
question; what is important is that the disk operating system knows how to
get to the right block when a request is made of it.
The second concept, that of the "logical" layout of the disk, has to do
with the way in which the disk operating system organizes the physical blocks
on each track. Imagine a phonograph record on a turntable (some of you still
own those, don't you?) It physically resembles a floppy disk; it is just
larger in size and is not "floppy". Mentally take a white marking pen and
draw lines through the center of the record, across the entire surface from
side to side, making the record resemble a pizza that has been cut up into
wedges.
Now draw a series of concentric circles, from the outside of the record down
to the center. Each ring will, of course, be smaller than the previous ring.
The rings you have drawn represent "tracks" on our simulated floppy disk, and
the lines running through the center of the record represent the division of
each track into blocks. Suppose we drew enough lines to divide the record up
into twelve "pieces" (of pizza). That means that each "track" has twelve
"blocks".
Now that you have your disk divided up (you just "formatted" it!),
let's store some data on it. Numbering each "block" from one to twelve (like
the numbers on a clock), let's put a checker into each block on the first
(outermost) "track" (yes, a checker. You know--from the game?) Repeat the
process on the second track, then the third, and so on, as far as you can go.
Eventually you won't be able to fit checkers into the blocks, because they
will get too small. (This points out one of the limits of floppy disks; at
some point the available space on the disk becomes so small it is unusable.
A standard 5.25 disk for the Apple II can have anywhere from 35 to 40 tracks
(Apple has always supported only 35 tracks), while the 3.5 disk has 80
tracks. The checkers we have put in the "blocks" on this disk have also been
labelled, but with the letters "A" through "L" for the first track, and "M"
through "X" for the second track, and so on.
Turn on the record player. If you hold your hand over one spot on the
first track on the record, you can see the lettered checkers as they move
past. As it goes by, grab the "A" checker, then the "B" checker, and so on.
Likely, after picking up checker "A" (on block 1), you had to wait for an
entire rotation of the record before "B" comes by on block 2. The same goes
for "C", "D", and so on. In computer terms, the "interleave" on this disk is
1 to 1 (written as 1:1). If you were EXTREMELY fast, you could pick up "A",
"B", "C", etc. as quickly as they went by, without having to wait for the
next revolution of the record. While few of us would be that fast, many of
us could pick up a checker after about four went by that we didn't need.
"Reload" your data on this disk, this time putting checker "A" on block 1,
then checker "B" on block 5, checker "C" on block 9, checker "D" on block 2,
check "E" on block 6, and so on. Now, as the record spins, you might be able
to pick up "A", "B", "C", and so on without having to wait for the next
revolution of the record. This would be (approximately) a 4:1 interleave.
With this "logical" layout, you can pickup (load) checkers from the disk, and
replace (store) checkers on the disk more efficiently. If your hands are
still not fast enough, you may need to increase the interleave to 6:1 or even
8:1. If your hands are faster, you could possibly use a 3:1 or 2:1
interleave.
This is roughly what happens with disk access. A disk device and
operating system that is extremely quick about processing the data it reads
off a disk can have a short interleave (1:1 or 2:1). A slower disk device or
operating system may need to use a 4:1 or higher interleave to work most
efficiently.
One last note: Because a track on a disk contains a continuous stream
of data bits, Apple drives were designed from the beginning to use
"self-synchronization" to be able to tell one byte from the next. This
continuous series of bits would be similar to having a paragraph of text with
no spaces between words. If a sentence read "GODISNOWHERE", does it mean
"GOD IS NOWHERE" or "GOD IS NOW HERE"? Some method is needed to let the
computer doing the reading know where the "spaces" between bytes exists. I
won't go into detail on exactly how this is carried out, but suffice it to
say that some bytes on the disk are reserved for this decoding process, and
so the true data bytes are specially encoded to not be mistaken for the
self-sync bytes. The process of decoding these "raw" data bytes is called
de-nibblization, and translates about 700 of the raw bytes read directly from
the disk into 512 true data bytes. This is another part of the overhead
necessary when reading from or writing to the disk; it would be similar to
having to draw something on each checker with a marker as it was removed from
the spinning record described above.
THE UNIDISK 3.5 AND APPLE 3.5
The first new disk drive that Apple released after the original Disk II
was a 400K, single-sided 3.5 inch drive for the original Macintosh. Then, in
September 1985 Apple finally released a similar drive for the Apple II
series, one that was not simply a cosmetic improvement of the original
Disk II drive. The UniDisk 3.5 drive was a double-sided version of the Mac
drive, and could hold 800K of data. The only connection that this new drive
had with the original 5.25 drives was a chip used on its controller card;
this IWM chip (for "Integrated Woz Machine") put the function of the original
Disk II controller onto a single chip, plus the enhancements needed to
operate this higher density drive.<4> Apple's design for the UniDisk 3.5 was
unique, in that it used a modification to Sony's design that varied the speed
of disk rotation, depending on which concentric track was being accessed.
This change made it possible for data to be packed compactly enough in the
smaller inner tracks to gain an extra 80K beyond the 720K that was originally
possible.
The UniDisk was directly supported by the newer Apple IIc motherboards
(as mentioned in the previous part of this History), but for the older
Apple II's a special controller card was required. The UniDisk 3.5 was
designed as an "intelligent" drive, and had a self-contained 65c02 processor
and memory to temporarily store ("buffer") data being read from or written to
the disk. This was necessary because of the slow 1 MHz speed of the 6502
processors in the Apple II; they could not keep up with the faster data
transfer rates possible with the 3.5 disk mechanism, plus the overhead of
de-nibblization. This extra processing did cut down the speed in the UniDisk
data transfer rate, but compared to the older Disk II drives it seemed MUCH
faster.
With the release of the Apple IIGS in September 1986 came a new version
of the 800K 3.5 drive called the Apple 3.5. This mechanism could be used on
either a Mac or Apple II, fitting into the trend at Apple at making
peripherals compatible between the two computers. The major difference
between this drive and the original UniDisk 3.5 was that it had been
lobotomized to be a "dumb" drive. Gone was the internal 65c02 processor chip
used in the UniDisk 3.5 (which made it an "intelligent" drive) and the
ability of the drive to buffer its own read and write operations. The newer
Apple 3.5 drive did away with the extra circuitry, leaving it to the computer
to handle direct control of the drive. This could be done in the IIGS
because of its faster 65816 microprocessor, which could keep up with the
higher rate of data transfer. Recall the above discussion of interleave?
The original UniDisk 3.5 worked best with an interleave of 4:1, but the
Apple 3.5 used 2:1 interleave and could do disk reads and writes faster.
Disks formatted with either drive were usable with the other one, but would
be slower on the "foreign" drive.<5>
Overall, Apple released four versions of 3.5 drives between 1984 and
1986. First was the 400K drive used on the original Macintosh, then the 800K
UniDisk 3.5 (which wouldn't work on the Mac), then an 800K drive for the Mac
(which wouldn't work on the Apple II), and finally the Apple 3.5 drive, which
worked on the Apple IIGS and the Mac, but not the IIe and original IIc.<5>
THE APPLE IIC PLUS: HARDWARE
Recalibrating our special time-travel card to focus on the final 8-bit
version of the Apple II, let's travel to mid-1987. It was at this time that
someone at Apple decided that the IIc needed to be upgraded. Shortly before
July, three years after its original 1984 introduction, it was felt that the
Apple IIc would benefit from the larger capacity Apple 3.5 drive as its
internal drive. The primary intent was to make only this change, while
leaving the rest of the IIc as it was. As with most other Apple projects,
this went by various internal code names during its development, includine
Pizza, Raisin, and Adam Ant.<11>
Trying to use the Apple 3.5 drive in the Apple IIc was certainly an
engineering problem. As mentioned above, the 1 MHz 65c02 was simply not
fast enough to take raw data off the Apple 3.5 drive, de-nibblize it into
usable data, and pass it to the operating system. The "intelligent" 3.5
drive was designed in the first place for that very reason. To solve the
problem, Apple contracted with an outside firm to design a special digital
gate array that made it possible for the 1 MHz 65c02 to just barely keep up
with the data transfer rate from the Apple 3.5 drive. In accomplishing
this, it needed an extra 2K of static RAM space to de-nibblize the raw data
from the 3.5 drive. This extra memory had to be available OUTSIDE the
standard Apple IIe/IIc 128K RAM space, since there was simply not enough
free memory available to spare even that little bit of space. The code
Apple engineers wrote to use the drive was SO tight that there were EXACTLY
enough clock cycles to properly time things while controlling the drive.
(Each assembly language instruction takes a certain number of clock cycles;
these cycles have to be taken into account for timing-sensitive operations
such as disk and serial port drivers).
To support older Apple II software that came only on 5.25 disks, the
disk port on the back was now changed to handle not only external 3.5 drives
(either UniDisk 3.5 or Apple 3.5), but also up to TWO Apple 5.25 drives which
could be chained together (the same drives used with the Apple IIGS). These
could be chained together as could the 3.5 drives. The IIc Plus, then, could
have three additional drives attached, in any mixture of Apple 3.5,
UniDisk 3.5, or Apple 5.25 drives.<6>
The IIc Plus design was not thought out completely from start to
finish, however. After they did the work with the special gate array to make
the original IIc architecture work properly, someone decided that it was not
a good idea to release a 1 MHz computer in 1987. People want speed, they
reasoned; look at the world of the IBM PC and its clones, where each year
faster and faster models are released. They decided then to retrofit the new
IIc with a faster 4 MHz version of the 65c02. That change, had it been done
from the start, would have made engineering the internal 3.5 drive simpler;
they could have just used the processor at 4 MHz for 3.5 drive access, and
then used the true system speed (as selected by the user) for all other
functions. The complicated gate array would not have been necessary. But,
since the faster speed was added as an afterthought, and the project was
under a tight schedule, the gate array design was not changed.
To accomplish the faster processor speed for the IIc Plus, Apple went
to another outside firm, Zip Technologies. This company had already marketed
an accelerator, the Zip Chip, that was popular as an add-on product for
existing Apple II computers. Users could simply remove the 6502 or 65c02
chip in their computer, replace it with the special Zip Chip, and suddenly
they had a computer that ran up to four times as fast. Apple licensed this
technology from Zip, but engineers balked at actually using the Zip Chip
itself for the IIc Plus. Part of this was because of the size of the Zip
Chip. The chip was shaped like a standard integrated circuit, but was
thicker vertically than a basic 65c02. Inside the extra space was a fast
65c02 processor, plus some caching RAM, all squeezed into a space that would
fit even into the original Apple IIc (where space was at a premium). (The
Zip Chip "cache" is a piece of RAM memory that is used to hold copies of
system memory that the processor is frequently accessing. For instance, if a
lot of graphics manipulation is being done by a program, the caching RAM
would hold a copy of part of the graphics RAM, and could access it much
faster than the standard RAM. This is part of what makes an after-market
accelerator work).
Zip had wanted Apple to buy their Zip Chip and simply use that product
in the IIc Plus. Obviously, this would have been to Zip's advantage
financially. However, the thicker vertical size of the Chip made testing the
completed computer more difficult, and it would be a problem to isolate
product failures to the Zip Chip, instead of something else on the
motherboard. By using a 4 MHz 65c02 and two 8K static RAM chips as separate
components in the IIc Plus, Apple engineers could ensure that it would work
and be available in a large enough volume for production. When they were
designing the IIc Plus, Zip Technologies could not guarantee they could
provide reliable products in the volume Apple needed.
The IIc Plus did not have the 12 VDC input on the back panel as did the
earlier IIc's; instead, the power supply was built-in. This was not because
it was necessarily a better design, as an internal power supply was actually
less reliable ultimately than the external power supply. (It exposes the
internal components to higher levels of heat over the lifetime of the
product). But because many people had criticized Apple about the IIc
external power supply (called a "brick on a leash" at Apple), that they had
decided to make it internal on the IIc Plus as it was on all their other
products. This change apparently did not cause any significant problems, as
few people were actually trying to use the IIc as a "portable" computer (with
a battery pack).
The memory expansion slot on the IIc Plus was not compatible with the
memory cards that Apple had produced for the older IIc. This was primarily a
timing problem; it was not because the RAM chips in the memory card were not
fast enough to keep up with the 4 MHz speed of the IIc Plus. (Older IIc
users can use an Apple Memory Expansion card with an 8 MHz Zip Chip with no
problems). The IIc Plus also had an additional connector at the opposite end
of a memory card plugged into the expansion slot. Signals from port 2 were
made available at that end, so third party companies could make a card that
was a combination RAM card and internal modem. However, this never did come
about (see below).
Other changes in the IIc Plus included a slightly redesigned keyboard
and mini-DIN-8 connectors on the back panel for its serial ports (to be more
compatible with Apple's new Macintosh and IIGS keyboards).
One interesting note: John Arkley, one of the engineers working on the
project and a long-time Apple employee, campaigned long and hard to take
things a step further. He wanted them to take an Apple IIGS motherboard,
remove the slots, change the ROM to support only the internal "slots", and
release a IIGS in a IIc case. He felt it would have made a great portable,
non-expandable IIGS, but could not get anyone who could approve the plan to
get interested in the idea.
THE APPLE IIC PLUS: FIRMWARE
The IIc Plus ROM was called revision 5 (the previous Revised Memory
Expansion IIc was labelled as revision 4). The main changes present were the
ones that supported the internal Apple 3.5 drive. Firmware on the new IIc
was not any larger than the 32K on the previous models, but it did use the
entire space (the previous IIc didn't use the last 8K available in the ROM).
One minor bug that slipped by in the IIc Plus firmware was an inability
to deal with 400K (single-sided) 3.5 disks. There were few commercial
software packages that came on such disks, however.<7>,<8>
THE APPLE IIC PLUS: INTRODUCTION
In September 1988 the Apple IIc Plus was introduced to considerably
less fanfare than the original IIc was in April 1984. There were no promises
of "Apple II Forever" this time; instead, it warranted little more than a
press release in various Apple II magazines of the time. Its selling price
was $675 (or $1,099 with a color monitor). This was remarkable, considering
that the original Apple IIc WITHOUT a monitor sold for nearly double the
price ($1,295) and had far less capacity and power than this new version.
Some models of the IIc Plus were even shipped with 256K of extra memory
already added. It was faster than any other Apple II ever produced
(including the 2.8 MHz IIGS), and was probably the finest 8-bit computer
Apple ever produced.
THE APPLE IIC PLUS: LESS THAN A SUCCESS
Early on, the Apple IIc Plus was a big seller, and by January 1989 it
was above forecasted sales levels. However, the biggest hurdle that the
IIc Plus had to overcome was not the external marketplace, but rather the
internal market opinions at Apple Computer, Inc. Since Macintosh-mania was
still in full swing at Apple, and that younger brother of the Apple II was
getting most of the attention from management, the IIc Plus (as well as the
IIGS) suffered. It was not because of a lack of capability, but primarily
from failure to thrive due to inadequate home nutrition, so to speak. Also,
the IIc Plus had the same problem as the original Apple IIc; customers seemed
to want the IIe with its slots, or the greater power of the IIGS.
There were some products that were designed by third-party developers
for both the IIc and IIc Plus that never made it to the market for various
reasons. Applied Ingenuity (later known as Ingenuity, Inc) had two products
that would have markedly increased the portability of the IIc/IIc Plus. One
was an internal hard disk they called "CDrive", which would have replaced the
Apple IIc or IIc Plus internal floppy disk drive (converting it into an
external floppy drive). Even more unique was "CKeeper", which was a
multi-function card with many features. It could hold up to 1.25 MB of extra
RAM; it had a clock/calendar chip that was ProDOS compatible; it had firmware
routines to support dumping text or graphics screens to the printer; it could
function as a built-in assembly language program debugger; and best of all, a
feature called RAMSaver, which maintained power to the RAM chips during a
power failure or if the power switch was turned off. Both of these products
never saw the light of day, primarily because the company went out of
business before they could be finished.<9>
Chinook Technologies actually finished design on an internal modem for
the IIc Plus, but never released it. This card, 1.5 by 6 inches in size,
would have mounted inside the disk drive shield. It connected to a small box
attached to the outside of the IIc case, where there were cut-outs provided
by Apple for connection of an "anti-theft" cable. This external box had
phone jacks for the phone line and a telephone, just like most external
modems. Undoubtably it never was released because of Apple's indifference
towards the IIc Plus.<10>
With inadequate support by Apple marketing, third-party hardware and
software developers had little motivation in designing any new products for
the IIc Plus. Therefore, no unique products ever emerged on the market to
take advantage of its features. Finally, in September of 1990 the IIc Plus
was discontinued by Apple, leaving the platinum Apple IIe and the Apple IIGS
as the remaining bearers of Wozniak's legacy.
++++++++++++++++++++++++++++++++++
NEXT INSTALLMENT: The Apple IIGS
++++++++++++++++++++++++++++++++++
NOTES
<1> Thyng, Mike. "Apple Source", PEEKING AT CALL-A.P.P.L.E., VOL. 1,
1978, pp. 7-8.
<2> -----. -----, APPLE ORCHARD, VOL. 1, NO. 1., Mar-Apr 1980, various.
<3> -----. "Tomorrow's Apples Today", CALL-A.P.P.L.E., May 1984, p. 78.
<4> -----. "The Marketplace", CALL-A.P.P.L.E., Jul 1985, p. 49.
<5> Baum, Peter and Allen. "Speaking Of Hardware", CALL-A.P.P.L.E.,
Oct 1987, pp. 30-34, 51.
<6> Weishaar, Tom. "Apple rediscovers the Apple II", OPEN-APPLE, Nov
198, p. 4.73.
<7> Weishaar, Tom. "Ask Uncle DOS", OPEN-APPLE, Jan 1989, p. 4.91.
<8> Weishaar, Tom. "Miscellanea", OPEN-APPLE, May 1989, p. 5.27.
<9> -----. "Ingenuity News", II AT WORK, Vol. 2, No. 1, Spring 1990,
p. 30.
<10> Hoover, Tom. (personal mail), GEnie, E-MAIL, Nov 1991.
<11> A+ Staff. "NewsPlus", A+ MAGAZINE, Oct 1989, p. 18.
APPLE II HISTORY
===== == =======
Compiled and written by Steven Weyhrich
(C) Copyright 1991, Zonker Software
(PART 10 -- THE APPLE IIGS)
[v1.0 :: 06 Dec 91]
THE APPLE II EVOLVES
While the capabilities of the Apple II slowly advanced as it changed
from the II up through the IIc, the one thing that remained essentially
unchanged was the 6502 microprocessor that controlled it. Even though the
65c02 had more commands than the 6502, as an 8-bit processor it was
inherently limited to directly addressing no more than 64K of memory at one
time. (As an 8-bit processor, the 6502 could handle only 8 bits, or one byte
at a time. However, its address bus was 16 bits wide, which made for a
maximum address of 1111 1111 1111 1111 in binary, $FFFF in hexadecimal, or
65535 in decimal. If you divide 65536 bytes by 1024 bytes per "K", you get
64K as the largest memory size). When Wozniak designed it, 64K was
considered to be a massive amount of memory, even for some mainframe
computers. (For example, the old mainframe on which I learned programming
during college back in 1975 was a ten-year-old IBM 1130 with 8K of memory;
this was used for both the operating system AND user programs!) Most hackers
of the time would not have known what to DO with four megabytes of memory,
even if it had been possible (or affordable) to install that much.
Consequently, programs of the day were compact, efficient, and primarily
text-based.
The non-Apple II computer world had developed and advanced, and Apple
grudgingly allowed the Apple II to make its small, incremental advances.
Occasionally, efforts were made within Apple to make a more powerful
Apple II, but the lure of "better" computers always turned the attention of
management away from allowing such a project to actually make any progress.
First the Apple III, then Lisa, and finally Macintosh swallowed the research
and development dollars that Apple's cash cow, the Apple II, continued to
produce. The latter two computers were based around the 16-bit Motorola
68000 microprocessor, which had the capability to address far more than 64K
of memory. The Apple II could make use of more memory only through
complicated switching schemes (switching between separate 64K banks).
Although "Mac-envy" hit many Apple II enthusiasts both inside and outside of
Apple, causing them to move away from the II, there were still many others
who continued to press for more power from the II.
Eventually, a company called Western Design Center revealed plans to
produce a new microprocessor called the 65816. This chip would have all of
the assembly language opcodes (commands) of the 65c02 through an "emulation"
mode. However, it would be a true 16-bit processor, with the ability handle
16 bits (two bytes) at a time and to address larger amounts of continuous
memory. The address bus was enlarged from 16 to 24 bits, making the 65816
capable of addressing 256 times more memory, or 16 megabytes. The power to
make a better Apple II was finally available.
THE RETURN OF WOZNIAK
Back in early 1981, Steve Wozniak was involved with several projects at
Apple. He had helped write some fast math routines for a spreadsheet product
that Apple had planned to release in competition with Visicalc. Also, Steve
Jobs had managed to convince Wozniak to participate with his fledgling
Macintosh project. Then, in early February, Wozniak's private plane crashed.
He was injured with a concussion that temporarily made it impossible to form
new memories. He could not recall that he had an accident; he did not
remember playing games with his computer in the hospital; he did not remember
who visited him earlier in the day. When he finally did recover from the
concussion, he decided it was time to take a leave of absence from Apple.
Wozniak married, and returned to college at Berkley under the name "Rocky
Clark" (a combination of his dog's name and his wife's maiden name). He
decided he wanted to finally graduate, and get his degree in electrical
engineering and computer science. When he was done with that, he formed a
corporation called "UNUSON" (which stood for "Unite Us In Song") to produce
educational computer materials, wanting to make computers easier for students
to use. He also decided use UNUSON to sponsor a couple of rock music events,
and called them the "US Festival".<1> Held on Labor Day weekend in 1982 and
1983, these music and technology extravaganzas were invigorating for Wozniak,
but he lost a bundle of money on both occasions. Though nowhere near drying
up the value of his Apple Computer stock, he decided that he was ready to
return to work. In June of 1983, Wozniak entered the building on the Apple
campus where the Apple II division was housed and asked for something to do.
THE APPLE IIX
When Wozniak returned, he discovered the latest of the Apple II
modernization projects, which was code-named "IIx". When he saw what the
65816 could do, he became excited about the potential of the new Apple II and
immediately got involved. It was a tremendous boost in morale for the
division to have their founder return to work. However, the IIx project was
plagued by several problems. Western Design Center was late in delivering
samples of the 65816 processor. First promised for November 1983, they
finally arrived in February 1984--and didn't work. The second set that came
three weeks later also failed.
Other problems came out of the engineering mindset that still existed
at Apple at the time. Recall that people there liked designing boxes that
would do neat things, but there was not enough of a unified focus from above
to pull things together. The marketing department wanted the IIx to have a
co-processor slot to allow it to run different microprocessors. The code
name of the project by this time was "Brooklyn" and "Golden Gate" (referring
to the ability to make it a bridge between the Apple II and Macintosh). The
co-processor slot could allow the IIx to easily do what third party companies
had done for the original Apple II with their Z-80 boards (which allowed them
to run CP/M software). Co-processor boards considered were ones for the
Motorola 68000 (the chip used in the Macintosh), and the Intel 8088 (used in
the IBM PC). The IIx project got so bogged down in trying to become other
computers, they forgot it was supposed to be an advanced Apple II.
Politically it also had problems at Apple, because it was being aimed as a
high-end business machine, which was where they wanted the Macintosh to
go.<2>,<3> Wozniak lost interest as things ran slower and slower, and
eventually the project was dropped.
THE 16-BIT APPLE II RETURNS
When the IIx project was cancelled in March 1983, some of the Apple II
engineers were assigned the task of reducing the cost of the Apple II.
Engineers Dan Hillman and Jay Rickard managed to put almost the entire
Apple II circuitry onto a single chip they called the Mega II. Meanwhile,
after the "Apple II Forever" event that introduced the IIc, interest in the
Apple II revived and sales were quite good. Management saw that sales of the
open IIe were better than the sales of the closed IIc, so they were agreeable
to the idea of another try at the 16-bit Apple II, possibly utilizing the
Mega II chip. By late summer 1984 it was revived with the code name
"Phoenix" (rising from the ashes of the IIx project).<3>
THE APPLE IIGS: GOALS OF THE DEVELOPMENT TEAM
The people involved in the Phoenix project were very knowledgeable
about the Apple II, from the days of the ][ through the //c. They knew what
THEY wanted in a new computer. It should primarily be an Apple II, not just
something NEW that tried to be all things to all people.<4> Dan Hillman, who
had also been involved as the engineering manager for the IIx project, stated
in an interview, "Our mission was very simple. First we wanted to preserve
the Apple II as it exists today. It had to work with Apple IIe software and
Apple IIc software. That was goal number 1. But we recognized that the
Apple II was an old computer. It had limitations. The new machine needed to
address those limitations, break through those barriers--and the barriers
were very obvious: We needed to increase the memory size. We had to make it
run faster. We needed better graphics. And we had to have better sound.
That was our mission." Since advanced graphics and sound were what would
make this new Apple really shine, the name eventually assigned to the final
product was "Apple IIGS".<3>
Having learned from their experience in building the Apple IIe and IIc,
they knew what would make the new 16-bit Apple II more powerful. The
Apple IIc was easy to use because the most commonly needed peripherals were
already built-in. The Apple IIe, however, excelled in its ability to be
easily expanded (via the slots) to do things that were NOT commonly needed or
built-in. Harvey Lehtman, system software manager for the project, stated,
"We ... wanted the Apple IIGS to be easy to set up, like the IIc, and easy to
expand, like the IIe."<3>
THE APPLE IIGS: ARCHITECTURE
Wozniak was quite involved in designing the general layout of the IIGS.
Insisting on keeping it simple, he recommended AGAINST a built-in
co-processor (as they tried to do with the IIx). He also wanted to keep the
8-bit part of the machine separate from the 16-bit part. To accomplish this,
he and the other engineers decided to design it so the memory in the lower
128K of the machine was "slow RAM", which made it possible for it to function
just as it did on the older Apple II's. This included the memory allocation
for the odd addressing schemes used in the text and graphics modes and (which
made sense in 1976, but not in 1986). The rest of the available memory space
would be fast, and could be expanded to as much as 16 megabytes. With a
faster microprocessor, it would also be possible to run programs more quickly
than on the older Apple II's.<3>
THE APPLE IIGS: GRAPHICS
One area they decided to focus on was bringing the quality of graphics
on the new Apple II up to modern standards. Rob Moore, the Phoenix project
hardware group manager, helped define the new graphics modes of the IIGS.
Because a change that increased the vertical resolution from 200 dots to 400
dots would make the computer too expensive (it would require a special
slow-phosphor monitor), they purposely decided not to go in that direction.
Instead, they increased the horizontal resolution, and created two new
graphics modes (called "super hi-res"); one was 320 x 200 and the other was
640 x 200. This decision also made it easier to keep compatibility with
older graphics modes.<3>
As mentioned above, the text and graphics addressing on the old
Apple II was odd, from a programming standpoint. When Wozniak originally
designed the II, he made the memory allocation for text and graphics to be
"non-linear", since this saved several hardware chips and made it less
expensive to build. This meant that calculating the memory address of a
specific dot on the hi-res graphics screen or a character on the text screen
was not as simple as most programmers wanted. The hi-res screen began at
$2000 in memory, and the first line on the hi-res screen (line 0) started at
that address. Each line on the hi-res screen was made up of 40 bytes of 8
bits each, and seven bits of each byte represented a dot or pixel on the
screen, giving a possible 280 dots horizontally. Since 40 bytes is $28 in
hex, line 0 then ran from $2000 to $2027 in memory. However, the second line
(line 1) of the hi-res screen did NOT start at $2028 as one would expect, but
at $2080. The hi-res screen line represented by memory locations $2028 to
$204F was line 8, and $2050 to $2077 was line 16. The last eight bytes of
this 128 byte section of memory was unused. The next 128 bytes were
allocated to screen lines 1, 9, and 17, and so on.
Because this complicated things considerably for programmers, the
design team for the IIGS wanted linear addressing, which would allow the
memory addresses of line 0 to be followed by the addresses for line 1, and so
on. Because the graphics resolution and range of available colors planned
was much greater than either of the older graphics modes (hi-res or double
hi-res), they needed 32K of continuous memory to use. Because they planned
on a minimum memory configuration of 256K for the IIGS as it would be
shipped, they could not come up with that much memory in one single block.
Engineer Larry Thompson designed a special Video Graphics Controller (VGC) to
solve the problem. The chip combined two separate 16K blocks of memory and
make it appear as a single continuous 32K block of memory, as far as the
graphics programmer was concerned.<3>
The new super hi-res graphics modes also gave far more color choices
than either the old hi-res mode (which had six unique colors) or even the
double hi-res mode (which had sixteen colors). In the 320 x 200 super hi-res
mode, each line could have sixteen colors out of a possible 4,096, and in the
640 x 200 mode, each line could have four colors out of 4,096. This gave
graphics power that was not even available on a Macintosh (which was still
black and white at the time).
THE APPLE IIGS: SOUND
The second major area of focus for enhancements over the old Apple II
was sound reproduction. The original sound chip that had been proposed for
the IIGS would have given it the sound quality of a typical arcade game.
However, this was no better than what other computers in 1986 could do. Rob
Moore suggested using a sound chip made by Ensoniq, one that was used in the
Mirage music synthesizer. He had to push hard to get this included in the
final design, but was able to convince management of its importance because
he told them it would be "enabling technology" (borrowing a phrase from a
Macintosh marketing book). He told them "it would enable people to do things
they'd never dreamed of doing."<3>
The Ensoniq chip was capable of synthesizing FIFTEEN simultaneous
musical voices. To help it in doing such complex sound reproduction, they
gave the chip a separate 64K block of RAM memory dedicated specifically for
that purpose.
THE APPLE IIGS: MEMORY
The 65816 is designed to address up to 16 MB of memory. The IIGS,
however, was designed to support only 8 MB of RAM, and up to 1 MB of ROM (in
high memory). With cards specially designed by third-party companies, up to
12 MB of RAM could be added, but the memory manager in ROM was only aware of
the first 8 MB. A special patch was needed to allow the system to use memory
beyond that point.
Building on the traditional memory organization from 6502 days, memory
in the IIGS was usually referred to in banks, from $00 through $FF. Each
bank refers to a 64K chunk of memory. The lowest bank, $00, was identical to
the 64K memory space in the original Apple II. The next bank, $01, was the
same as the auxiliary memory bank used on the Apple IIe and IIc.
(Additionally, the super hi-res graphics display was found in 32K of the
memory in bank $00, from $2000 to $9FFF). The banks from $02-$7F were also
for RAM storage, and covered things up to the 8 MB limit. Banks $80-$DF
could be used for another 4.25 MB of RAM, but as mentioned above they were
unusable (without a patch) because the memory manager didn't know how to
access it.
The memory expansion slot designed for the IIGS only had two lines to
decode addresses. This allowed for direct access to each of four 256K RAM
chips, or four 1 MB RAM chips. In order to make use of the next 4 MB of RAM
some special logic was needed to find and use it. RAM cards with more than 4
MB were never directly supported by Apple.<5>
Banks $E0 and $E1 were a special part of RAM that was used to duplicate
("shadow") banks $00 and $01. This RAM was designed as "slow" RAM, and would
better be able to run some of the older 8-bit Apple II software. When
shadowing was active, anything a program did to addresses in banks $00 and
$01 was duplicated in banks $E0 and $E1. Although it appeared to a program
that it was running in the lower two banks, it was really running in the slow
RAM in banks $E0 and $E1.<6>
Banks $E2-$EF were undefined. The last one MB from $F0-$FF was
allocated to ROM. The lower 512K (banks $F0-$F7) were set aside for a
ROMdisk. (A ROMdisk is just like a RAMdisk, except it will not lose its
contents when power is turned off). For a ROMdisk to be installed, a device
driver for the disk had to be located at the beginning of bank $F0 (at
address $F0/0000), and the driver had to start with the phrase "ROMDISK".
The most common way this was used by third-party hardware providers was to
take some of the GS memory, protect it with a battery (so its contents didn't
disappear when the computer was turned off), and designate it properly to the
IIGS as a ROMdisk (even though it was simply protected RAM, and not true
ROM).<7>
The rest of the space from $F8-$FF was reserved for system ROM. The
original IIGS had ROM code only from $FE-$FF, while later versions expanded
this space to include $FC and $FD.
++++++++++++++++++++++++++++++++++++++++
NEXT INSTALLMENT: The Apple IIGS, cont.
++++++++++++++++++++++++++++++++++++++++
NOTES
<1> Miller, Jonathan. "The Life And Times Of Rocky Clark", SOFTALK,
June 1982, pp. 141-144.
<2> Pinella, Paul. "In The Beginning: An Interview With Harvey
Lehtman", APPLE IIGS: GRAPHICS AND SOUND, Fall/Winter 1986, pp.
38-44.
<3> Duprau, Jeanne, and Tyson, Molly. "The Making Of The Apple IIGS",
A+ MAGAZINE, Nov 1986, pp. 57-74.
<4> Hogan, Thom. "Apple: The First Ten Years", A+ MAGAZINE, Jan 1987,
p. 45.
<5> Regan, Joe. A2PRO ROUNDTABLE, Oct 1991, Category 16, Topic 2.
<6> Williams, Gregg. "The Apple IIGS", BYTE, Oct 1986, pp. 84-98.
<7> Nolan, Sean. "GS Memory Cards Compared", CALL-A.P.P.L.E., Aug
1987, pp. 10-17.
This is the ENTIRE series of articles that make up the Apple II
History. They are readable in either AppleWorks 2.x or 3.0, but will
require an expanded desktop for some segments.
Please feel free to make comments (on GEnie's A2 Roundtable, Category
2, Topic 16) or in E-mail (S.WEYHRICH) about the contents of these files.
PLEASE, if you detect any errors or have any corrections, let me know about
it. I would like to have as accurate a history as possible.
If you would like to print any of these files in a user group
newsletter, I only ask that you print any segment you use in its entirety,
and that you give me as the author credit for the work. Also, please send
me a copy of any newsletter in which it is printed. My address is:
Steven Weyhrich
Zonker Software
2715 N. 112th St.
Omaha, NE 68164-3666
(402) 498-0246
Enjoy!
APPLE II HISTORY
===== == =======
Compiled and written by Steven Weyhrich
(C) Copyright 1991, Zonker Software
(PART 11 -- THE APPLE IIGS, CONT.)
[v1.0 :: 06 Dec 91]
THE APPLE IIGS: MISCELLANEOUS HARDWARE
Other features Apple engineers added to make the Apple IIGS a next
generation computer included a built-in clock, slot space for internal
expansion cards, and the electronic equivalents of seven more expansion
cards.<1> Taking the cue from their experience with the Apple IIc, they
included as built-in features the peripherals that most users would want to
use. They allocated serial ports to slots 1 and 2, the classic 80-column
firmware to slot 3, the mouse controller to slot 4, a Smartport controller
to slot 5, a 5.25 inch disk controller to slot 6, and AppleTalk capability
to slot 7. (AppleTalk was Apple's network protocol that had been designed
originally for use with the Macintosh).
Because the engineers wanted to make the IIGS capable of connecting
to the AppleTalk network, the serial ports they planned were based on a
different communications controller chip than was used in the older Super
Serial Card and the Apple IIc serial controller. Although the new
controller chips were more capable than the older ones used on the 8-bit
Apple II's, telecommunications programs written for those older Apple's
wouldn't work. This was because most terminal programs, for the sake of
speed, were written to directly control the old Super Serial Card (rather
than going through the slower, built-in firmware commands). The
controlling commands necessary to manage the newer chip were very
different, and so caused such software to "break".<2>
The case and motherboard used in the Apple IIGS was made smaller than
that found in the IIe, both in order to make a smaller "footprint" on a
desktop, and also to make it easier to make an upgrade available for IIe
owners. They had wanted to make it possible even for Apple II and II Plus
owners to upgrade, but in the end it turned out to be just too expensive
and difficult to execute.<2>
The Macintosh engineering group was at this time designing a protocol
for interfacing standard input devices, such as keyboards, mice, and
graphics tablets. This protocol, called the "Apple Desktop Bus", was first
implemented on the Apple IIGS. It made possible the interchangability of
hardware devices between the Macintosh and Apple II lines, allowing Apple
to sell a common set of peripherals that both computers could use.<2>
THE APPLE IIGS: FIRMWARE
Firmware, you may recall, is that layer of controlling programs in
ROM on a computer that sits between an application program and the hardware
it is trying to control. On the IIGS, the firmware was designed after the
hardware was finalized. Unlike the older ROM that Wozniak included with
the original Apple II, the IIGS software engineers tried to make it more
than just a set of addresses to call to carry out a function (such as
clearing the screen). Rather, they wanted to make a more comprehensive
system (called a "toolbox") which could be more flexible for future
enhancements of the hardware and firmware. In particular, they didn't want
to have the addresses for carrying out certain functions to be fixed in a
single location as on the older Apples. This toolbox would have a single
address to call, and a specific command would be passed on through that
address. Set up like this, it would allow Apple's firmware programmers to
modify the ROM in the future without having to take trouble to make
multiple addresses in the ROM "line up" properly. Additionally, they made
it easy to "patch" the toolbox code in the ROM using code loaded from disk,
allowing programmers to fix errors that were later found without having to
replace the physical ROM chips.
At first, they were given 64K of space for the ROM, over four times
as much as was available on the original Apple II. Later, they had to go
back and ask for 128K of ROM, because of the many things that they needed
and wanted to do. Of course, Applesoft had to be present in ROM in order
to maintain compatibility with the older Apple II software. Additionally,
they also put all of the mouse-handling tools into the ROM (unlike the II,
II Plus, and IIe, which had to have the mouse firmware on a card in a
peripheral slot).<1>
A boost to the firmware design of the IIGS came, unexpectedly, as a
result of the merger between the Apple II and Macintosh divisions. This
merger came as part of the reorganization that coincided with the departure
of Steve Jobs from Apple. Since the Macintosh team was now working in the
same place as the IIGS designers, they were available to offer help and
ideas. Bill Atkinson, the programming wizard who wrote MacPaint and many
of the mouse tools for the Macintosh, helped in the creation of the mouse
tools and QuickDraw II for the IIGS. (This was the name given to the ROM
tools used to draw on the super hi-res screen, and was borrowed from the
older QuickDraw routines on the original Macintosh).<1>
To allow the user to easily configure certain features of the IIGS to
their own tastes, a "control panel" was designed (another idea borrowed
from the Macintosh). It was used to set the clock, the system speed
(between a "normal" 1 MHz and a "fast" 2.8 MHz), change the standard text
display from 40 to 80 columns, set colors for the text screen, set
sensitivity of the mouse and keyboard, and make the standard settings for
the printer and modem ports. These preferences were saved in a special
battery-powered RAM that would survive even when the system power was
turned off.<1>
THE APPLE IIGS: SYSTEM SOFTWARE
ProDOS needed to be updated to better take advantage of the
additional memory on the IIGS, as well as the larger storage devices that
were not very available when ProDOS was originally written. Back then,
five megabytes was felt to be quite a large disk size. By the time the
IIGS was designed, 40 megabytes was becoming a common standard. The new
IIGS-specific version, called "ProDOS 16", would also be able to handle any
number of open files at the same time (the older version of ProDOS was
limited to eight files open simultaneously).<1>
The first version of ProDOS 16 was more limited than Apple's
designers wanted it to be, but they didn't want to hold up the new IIGS
until a better version was ready. The version of ProDOS that would run
8-bit Apple II software (on the IIGS or older Apple II's) was renamed
"ProDOS 8". That version was modified to handle system interrupts better,
which was important on the IIGS because of the control panel feature and
the way in which the Apple Desktop Bus worked. (An interrupt refers to a
special signal that is sent to the microprocessor by a hardware device.
This signal "interrupts" what the processor is doing, redirects it to do
something else, and then returns the processor to what it was previously
doing. The mouse on the IIc and the mouse card for the other Apple II's
use interrupts to handle movements of the mouse).<2>
(Further details about ProDOS 16 and its later replacement system,
GS/OS, will be found in an upcoming part of the Apple II History).
IIGS PROJECT CODE NAMES AND TEAM MEMBERS
The earliest name used internally at Apple for the IIGS project was
Phoenix (as mentioned earlier). It was also known as "Rambo" (when the
design team was fighting for final approval from the executive staff),
"Gumby" (from an impersonation done at Apple's Halloween-day parade), and
"Cortland".<1>,<3>
Some of the members of the design team not yet mentioned here include
Nancy Stark (an early and energetic champion for the IIGS project); Curtis
Sasaki (IIGS product manager); Ed Colby (CPU product manager); Jim
Jatczynski (Operating System group manager); Fern Bachman (who worked to
ensure compatibility with existing Apple II software); Gus Andrate (who
developed the sound tools and the unified drive firmware); and Peter Baum,
Rich Williams, Eagle I. Berns, John Worthington, and Steven Glass, who each
developed part of the IIGS system software and firmware.<4>
THE APPLE IIGS: PRODUCT INTRODUCTION
In September of 1986, Apple introduced the new Apple IIGS, bundled
with an Apple 3.5 drive, for $999 (not including a monitor). Apple
management, somewhat surprised by the response that occurred in their
"Apple II Forever" event two years earlier, made the decision to heavily
promote this new Apple II. Why they came to this change of heart was
unclear. Although they showed no slowing in their plans for the Macintosh
(which was making steady progress in gaining acceptability in the business
world), a multi-million dollar marketing and media blitz was arranged to
promote the new IIGS as the ultimate home and recreational use computer.
Even employees at Apple who had worked on the IIGS project were startled
(but pleased) at the marketing intensity that was begun, and the order for
this came directly from the top. John Sculley himself had insisted that
the Apple IIGS be given highest priority. (Apple's CEO since 1983, he had
just a year earlier ousted founder Steve Jobs from day to day
responsibilities at Apple). Rumors flew, but were never confirmed, about a
shaken Sculley who had come to an executive staff meeting in July of 1986
with stories of strange things he had experienced. He had supposedly
received a frightening nighttime visit from a yellow-garbed alien who
called himself "Darth Vader" from the planet Vulcan. "He told me that he
would meld my brain if I didn't put all I could into marketing the
Apple IIGS! I have to do it!!", he was reported to have said, white-fisted
and pale, at that meeting. Despite the obvious references to
science-fiction movies and television of the 1960's and late 1970's, the
executive staff bowed to his requests (which were no less firm after
Sculley had taken a Valium and had a couple of Diet Pepsi's. After all, he
WAS the boss).
Of course, the IIGS was received by the Apple II community with
enthusiasm. After initial sales broke all previous records, including
those for the Macintosh, Apple re-doubled its efforts to promote this as
the computer for nearly everyone. After all, it had ties into the past
(compatible with Steve Wozniak's 4K Integer BASIC Apple II at its core),
and ties into the future (with the 16-bit technology and expanded memory).
Within a year it was outselling the Macintosh (which had also received a
boost in sales, thought to be benefiting from the wave of IIGS sales).
By 1988, a significantly enhanced Apple IIGS was released, with more
advanced system software (which worked more like the easy-to-use Macintosh
interface) and higher density graphics (the cost of better color monitors
had come down considerably since the initial design of the IIGS back in
1985). Apple even decided to take the unprecedented move of licensing the
Apple II technology to a couple of other companies, who worked on producing
IIGS emulators for other computers, including IBM and its clones! Software
and hardware sales hit a spiraling upward curve, which stimulated more
sales of computers from Apple, which increased software and hardware sales
further. Apple even produced a IIGS emulator of its own for the Macintosh
and Macintosh II series of computers. Eventually...
(Hold it. Something just doesn't seem right. I don't recall
things going NEARLY that well for the IIGS. Computer!
APPLE IIC: [ Tweedlesquirge ] State request, please.
AUTHOR: Compare time events just outlined in previous
section with known events in database notes.
APPLE IIC: Working... [ Blinkitydinkitydinkityzeerp ] Events
just described are from a parallel timeline, which
diverged from our own timeline in July 1986.
AUTHOR: Hmmm. Any way of moving into that timeline?
APPLE IIC: Negative. Insufficient energy available in my
power supply brick to actually make changes
necessary to alter the events in our timeline to
allow the above scenario to actually occur.
AUTHOR: Then HOW did we come across that information in
the first place?
APPLE IIC: Flux capacitor was affected by a momentary surge
in power lines due to a nearby thunderstorm.
AUTHOR: Interesting. Well, maybe someday I'll have to
beef up this power supply a bit and have a talk
with Mr. Sculley if I can find my yellow radiation
suit... So how do we get back to the correct
information?
APPLE IIC: You could effect a complete shutdown and memory
purge, then reload correct data from protected
archives.
AUTHOR: Very well. Make it so.
APPLE IIC: Working... [ Blinkitydinkitydinkityzeerpity... ]
PROOFREADER: Your Apple TALKS???
AUTHOR: What? Yes, well I had a CPU conversion done in
the early 24th century...
APPLE IIC: Data reload completed. You may proceed when ready.
AUTHOR: Now, let's see if we can get it right this time...)
THE APPLE IIGS: PRODUCT INTRODUCTION (Take 2)
In September of 1986, Apple introduced the new Apple IIGS, bundled
with an Apple 3.5 drive, for $999 (not including a monitor). The Apple II
community was excited about the new computer, and inCider magazine featured
a exuberant Steve Wozniak on the cover of its October 1986 issue with the
caption, "It's Amazing!"
Apple, for its part, did do some advertising for the new computer in
the pages of current Apple II publications of the time. However, there was
no major push for the new computer, and again it seemed destined to be
dwarfed by Apple's preoccupation with the Macintosh.
Though announced in September, the IIGS was not widely available
until November. Early production models of the IIGS had some problems; one
of the new chips did not work properly, and necessary changes to fix them
caused a delay. The upgrade that would turn an Apple IIe into a IIGS was
also delayed until early 1987.<5>
THE APPLE IIGS: ENHANCEMENTS
In September 1987 Apple made an incremental improvement to the IIGS
with the release of a new ROM. The ROM 01 revision made a few changes in
the original IIGS ROMs and included an improved video controller chip.
Bugs in the ROM code were fixed, and a problem with a "pink fringe" effect
with certain graphics displays was fixed. The new ROMs were not compatible
with any IIGS System Disks earlier than version 2.0. The new ROM was
identified by a message at the bottom of the screen when booting the IIGS
that said "ROM Version 01". The original IIGS had no message in this
location.<6>
The next change came with the release of the ROM 03 version of the
IIGS in August of 1989. This new IIGS computer came standard with 1 meg of
RAM on the motherboard, and twice as much ROM (256K versus 128K on the
older IIGS). This allowed more of the operating system to be in ROM,
rather than having to be loaded from disk when booting. Additionally,
fixes were made to known bugs in the ROM 01 firmware. (The latest version
of the IIGS system software made patches to ROM 01 to fix those bugs, but
these patches still had to be loaded from disk, which slowed startup time.
Having the latest new tools and fixed new ones already in ROM made booting
the version 03 IIGS a bit quicker). The new Apple IIGS also had the
capability of using both the internal slot firmware as well as using a
peripheral card plugged into a slot. The ROM 01 IIGS could, of course, use
cards plugged into the slots, but only at the expense of being unable to
use the internal firmware for that slot. With so much useful system
firmware built-in, a ROM 01 user who wanted, for example, to add a
controller card for a hard disk would have to give up either AppleTalk in
slot 7 or use of 5.25 disks in slot 6. Almost everything else had to be
set in the control panel to the internal firmware.
The ROM 03 IIGS also included enhancements for disabled users. A
feature called "sticky keys" made it possible to do multiple keypresses.
(To execute an "Option-Control-X" sequence, for example, required pressing
three keys at once. This was something that a paralyzed user with a
mouth-stick to press keys could not previously do). Also, more things that
had required a mouse now had keyboard equivalents (using the keypad). The
new IIGS also had somewhat "cleaner" sound and graphics. However, because
the improvements made were minimal compared to the cost of providing
upgrades to previous owners, no upgrade program was announced by Apple. In
any case, many of the new features could be obtained on older IIGS's by
upgrading the memory to at least one megabyte and using GS/OS System
Software 5.0.2 or greater.<7>
A feature that was added to the ROM 03 firmware that was entirely
fun, instead of functional, was accessed by a specific key-sequence. If
the computer was booted with no disk in the drive, a message that said
"Check startup device" appeared, with an apple symbol sliding back and
forth. At that point, if the user pressed the keys "Ctrl", "Open Apple",
"Option", and "N" simultaneously, the digitized voices of the Apple IIGS
design team could be heard shouting "Apple II!" Also, the names of those
people would be displayed on the screen. If running GS/OS System 5.0 or
greater, the user would have to hold down the "Option" and "Shift" keys,
then pull down the "About" menu in the Finder. It would then say "About
the System". Using the mouse to click on that title would cause the names
to be displayed and the audio message to be heard.
++++++++++++++++++++++++++++++++++++++++++++++++++++
NEXT INSTALLMENT: Peripherals & the Apple II Abroad
++++++++++++++++++++++++++++++++++++++++++++++++++++
NOTES
<1> Duprau, Jeanne, and Tyson, Molly. "The Making Of The Apple
IIGS", A+ MAGAZINE, Nov 1986, pp. 57-74.
<2> Pinella, Paul. "In The Beginning: An Interview With Harvey
Lehtman", APPLE IIGS: GRAPHICS AND SOUND, Fall/Winter 1986, pp.
38-44.
<3> Hogan, Thom. "Apple: The First Ten Years", A+ MAGAZINE, Jan
1987, p. 45.
<4> Szetela, David. "The New II", NIBBLE, Oct 1986, pp. 5-6.
<5> Weishaar, Tom. "Miscellanea", OPEN-APPLE, Nov 1986, p. 2.74.
<6> Platt, Robert, and Field, Bruce. "A.P.P.L.E. Doctor",
CALL-A.P.P.L.E., Nov 1987, p. 58.
<7> Doms, Dennis. "Apple upgrades IIGS hardware", OPEN-APPLE, Sep
1989, p. 5.57.
APPLE II HISTORY
===== == =======
Compiled and written by Steven Weyhrich
(C) Copyright 1992, Zonker Software
(PART 12 -- PERIPHERALS & THE APPLE II ABROAD)
[v1.1 :: 11 Jul 92]
THE APPLE II ABROAD
Early on, Apple got involved in selling the Apple II in Europe and
the Far East. To function in those parts of the world called for a change
to handle a different voltage (240V instead of the 120V we use in the
U.S.). Also, the language differences had to be overcome. It was easiest
in Europe where, for the most part, the standard Roman alphabet was used.
The primary differences were in symbols used together with letters for
certain specific uses. Apple's Europlus ][ had a modified ROM, and certain
ESC key sequences could generate the German umlaut symbol to go with
certain vowels.<1>
When the IIe was released there were some other differences. The
German version was built with a an external switch below the keyboard,
allowing the user to change between a standard U.S. layout and a German
layout. (American versions of the IIe lacked the switch, but had a place
on the motherboard that could be modified to allow a Dvorak keyboard layout
to be switched in instead of the standard keyboard). The IIe auxiliary
slot, which was placed in line with the old slot 0 on American versions
(but moved forward on the motherboard) was placed in front of slot 3 on
German versions. This was because the European Apple IIe's also had added
circuitry to follow the PAL protocol for video output used for televisions
and computer monitors in Europe (in the U.S. the NTSC protocol is
followed). Because of the extra space needed on the IIe motherboard for
the PAL circuits, the auxiliary slot had to be moved to be in line with
slot 3. Because the 80-column firmware was mapped to slot 3, if an
80-column card was installed in the auxiliary slot it was not possible to
use any other card in slot 3. Versions of the IIe made for other European
countries had similar modifications to account for regional
differences.<1>,<2>
When the Apple IIc came along, it was designed from the start to take
the foreign market into account. If you recall, the U.S. version of the
IIc had a standard layout when the keyboard switch was up, and a Dvorak
layout when the switch was down. European versions were similar to the
American layout with the switch up, and had regional versions that could be
swapped in with the switch down. The British version only substituted the
British pound sign for the American pound sign on the "3" key, but the
French, German, Italian, and Spanish versions had several different symbols
available. A Canadian version of the IIc was the same as the American with
the switch up, and had some other special symbols with the switch down.
This version was unique because each keycap had the symbols for both
switched versions. For example, the "3" key had the "3" and "#" symbols,
plus the British pound symbol, making it a bit more crowded than a typical
keycap.
The Apple IIGS continued the practice of making international
versions available, but improved on the design by making the various
keyboard layouts all built-in. On the IIGS it was selectable via the
control panel, as was the screen display of the special characters for each
type of keyboard.
APPLE II PERIPHERALS
Moving on, we will now take a look at hardware items that extend the
capability of the Apple II. The ability to add an external hardware device
to a computer has been there from the earliest days of the first Altair to
the present. In fact, the success of a computer has inevitably led to
hackers designing something to make it do things it couldn't do before.
The more popular the computer, the more variety you will find in hardware
add-ons. The Apple II, designed by a hacker to be as expandable as
possible, was once a leader as a platform for launching new and unique
hardware gadgets. Today, in 1991, the Apple II unfortunately no longer
holds the front position; it has been supplanted by the Macintosh and IBM
crowd. However, the Apple II still benefits from the "trickle-down" of
some of the best new devices from other computers (SCSI disk devices and
hand scanners, for example). This is due partly to emerging standards that
make it easier to design a single hardware device that will work on
multiple computers, and in the case of the Macintosh, because of Apple's
decision to make peripherals somewhat compatible between the two computer
lines.
Trying to sort out all the peripheral devices ever designed for the
Apple II series of computers into a sensible order is not easy. In this
segment of the Apple II History I'll try to give an overview of hardware
devices that were either significant in the advancement of the II, or
unique, one-of-a-kind devices. Obviously, this cannot be a comprehensive
list; I am limited to those peripherals about which I can find information
or have had personal experience.
WHAT IS A PERIPHERAL?
A basic definition of a peripheral would be, "Something attached to a
computer that makes it possible to do more than it could previously do."
It is called a "peripheral" because it usually is connected to the computer
after it leaves the factory. An argument could be made that something
built-in is not a peripheral, but as things have changed over time there
are some devices still called "peripherals" from force of habit, though
they are now built-in (hard disks come to mind). Quite probably, in time
manydevices that were once considered optional accessories will become so
essential that they will always be built-in.
Recall that the earliest computers came with almost nothing
built-in. They had a microprocessor, a little memory, some means of data
input and display of results, the ability to access some or all of the
signals from the microprocessor, and that was all. For those computers,
the first things that users added were keyboards and TV monitors to make it
easier to use them. Recognizing that the earliest hardware peripherals
were keyboards and monitors highlights one fact: Nearly everything that
is sold as a peripheral for a computer is either an input device, and
output device, or an interface to make it possible to connect input and
output devices. Exceptions are cards to add memory, co-processor cards to
allow it to run software from another computer, and accelerators to make
the computer run faster.
EARLY PERIPHERALS
When we come to the release of the first Apple II, two important
"peripherals" were built-in: A keyboard, and the circuitry to allow easy
connection of a TV monitor. It had, of course, the slots for inserting
expansion cards (none were available), a game port (for attaching the game
paddles that were included), a pin that could be used to connect an RF
modulator (so a standard television could be used instead of a computer
monitor), and a cassette interface. Since there were no cards available to
plug into the slots, you would imagine that the Apple II couldn't make use
of any other hardware. However, those early users who had a need usually
found a way around these limits.
To get a printed copy of a program listing, for example, was no
trivial matter. First, there were very few printers available. Those who
could, obtained old used teletypes salvaged from mainframe computers.
These noisy, massive clunkers often had no lowercase letters (not a big
problem, since the Apple II didn't have it either), and printed at the
blazing speed of 10 cps (characters per second). To use these printers
when there were yet no printer interface cards to make it easy to connect,
hackers used a teletype driver written by Wozniak and distributed in the
original Apple II Reference Manual (the "red book"). This driver sent
characters to the printer through a connection to the game paddle port.
One part of being a hacker, you can see, is improvising with what you
have.<3>
Another of the earliest devices designed for the Apple II came from
Apple Pugetsound Program Library Exchange (A.P.P.L.E.). They were involved
in distributing Integer BASIC programs on cassette to members of the group.
To make it easier to send those programs to the person responsible for
duplicating the cassette, Darrell Aldrich designed a means of sending the
programs over the telephone lines. There were no modems available at the
time, so his "Apple Box" was attached to the phone line with alligator
clips and then plugged into the cassette port on the Apple II. To send a
program, you first called up the person who was to receive it and got the
computers on each end connected to the Apple Box. The sender then used the
SAVE command in BASIC to tell the computer to save a program to tape. In
actuality, the program was being "saved" through the cassette "out" port to
the Apple Box, and onto the phone line connected. At the other end of that
phone line, the data went into the other Apple Box, which was connected to
the cassette "in" port on the other Apple II. That computer was executing
the LOAD command in BASIC to "load" the program from the Apple Box.
A.P.P.L.E. sold about twenty of these Apple Boxes at $10 apiece.<3>
INTERFACE CARDS
One of the first interface cards made for the Apple II was released,
naturally, by Apple. The Apple II Parallel Interface Card was released in
1977 and sold for $180.<4> Wozniak wrote the firmware ROM, and managed to
make it fit entirely in only 256 bytes. As a parallel device, it used
eight wires to connect the computer with a printer, one line for each data
bit in a byte. Various parallel devices also used one or more extra wires
as control lines, including a "busy" line (so the receiving device could
tell the sending device to stop until it was ready for more), and a "ready"
line (so the receiving device could tell the sending device to resume
transmission). Because each of the eight bits needed a separate wire, the
cables for parallel devices looked like ribbons and were not very compact.
Most of the early printers available required this type of interface.<5> A
problem noticed with Apple's card, however, was an inability to properly
handle these "busy" and "ready" signals (a process known as "handshaking").
One solution offered by a reader of Call-A.P.P.L.E. magazine in 1979 was to
add a couple of chips to the card. If that was not done, however, the only
way to do printouts that were very long was to either buy a 2K print buffer
that could be used with some early printers, or use the "SPEED=" statement
in Applesoft to slow down the speed at which data was sent to the
printer.<6>,<7>
Apple released the Centronics parallel printer card in 1978. Selling
for $225, it was specifically designed to work with Centronics brand
printers.<4> It was similar to the Parallel Printer Interface, but had
fewer control codes. The "Centronics standard" used seven data bits and
three handshaking bits.<8> It would automatically send certain control
codes to the printer when a program sent the proper command (such as a
change in line width). As such, it was limited to properly working only
with a Centronics printer, but many companies made printers that used the
same control codes and would work with it.<5>
In April 1978 the Apple II Communications Card came out, selling for
$225.<4> It was intended for use with a modem, and worked for speeds from
110 to 300 baud. The low speed (by today's standards) was for several
reasons. One was that most modems of the time were acoustic. With an
acoustic modem you dialed up the number yourself, and when you made a
connection you put the handset (that's the part you talk and listen with,
for you non-technical folks) into rubber sockets to seal out extraneous
sound. A tiny speaker and microphone in the modem were then used to send
and receive signals. This leads to a second reason for the low speeds of
the time, which was that greater than 300 baud communications was not
considered possible. In fact, the Phone Company was quite certain that
speeds over 300 baud were not possible with any modem, although they would
be glad to lease you a special data-quality phone line so you could get the
best possible connection at 300 baud.
The Apple II Serial Interface Card ($195) appeared in August of
1978.<4> Serial devices required fewer data transmission lines, and so
could work with more compact cables. Instead of sending each byte as eight
simultaneous bits as was done in parallel devices, serial interfaces send
each byte as a series of eight bits, which only took two wires; one to send
and one to receive data. Like the parallel cards, there were a couple of
other wires that went with the data lines to control handshaking. Also,
serial cards needed a means of letting the sending and receiving devices
identify when a byte began and ended, and the speed at which data was being
transmitted. This meant that some additional information, such as "start"
bits, "stop" bits, and "parity" bits, was needed.
The original version of the Serial Interface Card had a ROM that was
called the P8 ROM. It contained the on-card program that allowed a user to
print or otherwise communicate with the card without having to know much on
the hardware level. The P8 ROM didn't support handshaking that used two
ASCII control characters named ETX (Control-C) and ACK (Control-F), so a
later revision called the P8A ROM was released. (ASCII stands for American
Standard Code for Information Interchange). This worked better with some
printers, but unfortunately the P8A ROM was not compatible with some serial
printers that had worked with the earlier P8 ROM.
The Apple Super Serial Card firmware was finished in January 1981.
It was called "super" because it replaced both the older Serial Interface
Card and the Communications Card. To change from one type of mode to
another, however, called for switching a block on the card from one
position to another (from printer position to modem position). The Super
Serial Card was also able to emulate both the P8 and P8A Serial Cards,
making it compatible with most older software written specifically for
those cards.<9>
VIDEO CARDS
After getting a printer interface card (and printer), the next
variety of peripheral cards popular for the Apple II and II Plus were ones
that allowed display of 80 columns of text (which was rapidly becoming a
standard outside the Apple II world). An early entry into this market was
the Sup'R'Terminal card made by M&R Enterprises, the same company that made
the Sup'R'Mod RF modulator for the Apple II. One of the most popular of
the 80-column cards was the Videx Videoterm. Videx even made a display
card that would display 132 columns card for the Apple II, but it never
made much headway in the computer world (being supplanted by bit-mapped
graphics displays, ala Macintosh).<3>
Many other companies made 80-column cards, but for the most part they
were not very compatible with each other. One problem was deciding on a
method to place the characters on the 80-column screen. With the standard
Apple 40-column display, you could use either the standard routines in the
Monitor, or directly "poke" characters to the screen. With these 80-column
cards, they often used a standard from the non-Apple world, that of using
special character sequences to indicate a screen position or other
functions. For example, to put a character at row 12, column 2, a program
needed to send an ESC, followed by a letter, followed by 12 and 02.
Similar ESC sequences were used to clear the screen, scroll it up or down,
or do other things that Apple's built-in screen routines could do.
When the Apple IIe was released, with its RAM-based method of
displaying 80 columns of text, nearly all the older 80-column cards
disappeared from the market. As of 1991, only Applied Engineering still
makes one for those remaining II and II Plus users that don't yet have an
80-column display.
One unique video product was made by Synetix, Inc. around 1983.
Their SuperSprite board plugged into slot 7 (which had access to some video
signals not available on other slots), and was promoted as a graphics
enhancement system. It worked by overlaying the hi-res screen with
animated "sprite" graphics (programmable characters that moved
independently on any screen background). Since each sprite was on its own
"plane" on the screen, they didn't interfere with each other. Also, it
didn't take extra effort bythe 6502 microprocessor to manipulate the
sprites; once the programmer placed the sprite on the screen and started it
moving, it would continue until told to change. This was much easier than
trying to program a hi-res game using standard Apple graphics.
Unfortunately, at the price of $395 it never took off. (It was hard for
developers to justify writing programs for only a few users that might have
this card). Another company later made a similar card called the
StarSprite, but it suffered the same fate. Even Apple's own double hi-res
graphics, introduced on the IIe, had the same problem with a small supply
of supporting software until the IIc and IIGS market got large enough to
guarantee that enough owners had the capability of displaying double
hi-res.<10>
ROM/RAM EXPANSION CARDS
All peripheral cards released for the Apple II up to the time of the
Apple II Plus were usable only in slots 1 through 7. Slot 0 was designed
differently, and until the release of the Applesoft Firmware Card ($200) in
1979 nothing had been built to make use of it. The Firmware Card contained
ROM that paralleled the upper 12K of Apple II memory. If you recall from
the discussion in Part 3 of this History, Integer BASIC and the ROM version
of Applesoft covered the same space in memory, and so could not co-exist.
When it was clear that a floating-point BASIC (Applesoft) was what many
people wanted, the II Plus came out with Applesoft in ROM. To make sure
that the previous Apple II owners were not left out, Apple released the
Applesoft Firmware Card to plug into slot 0. It had a switch that allowed
the user to select which BASIC should be active. In one position, the
motherboard ROM would be selected, and in the other position the Applesoft
and Autostart ROM was selected. Because there were quite a few Integer
BASIC programs that Apple II Plus users wanted to run, the Firmware Card
also came out in an Integer BASIC version with the old Monitor ROM, that
allowed II Plus users to simulate owning a standard II.<4>
One of the benefits of the Integer BASIC ROM was the lack of
something known as a "RESET vector" in the Autostart ROM. The Autostart
Monitor was called that because it would automatically try to boot the
Disk II drive when the power was turned on, and jumped to a known memory
location when the RESET key was pressed. This allowed the disk operating
system to reconnect itself, but more importantly made it possible to create
copy-protected software. Since the Autostart ROM made it possible for a
programmer to do something on RESET that prevented a user from examining
his program, it was popular with companies producing programs that they
didn't want copied and freely given away. Usually, a RESET on a protected
program would restart the program, erase the program from memory, or
re-boot the disk. The Integer BASIC and Old Monitor ROM lacked this
feature; a RESET would just drop the user into the Monitor. This, of
course, was just what hackers and those who liked to break copy-protection
wanted. The users with non-Plus Apple II's or with the Integer BASIC
Firmware Card on a II Plus could prevent a RESET from restarting
anything, allowing them to hack a program as much as they wanted.
The next card Apple released for slot 0 was called the Language Card.
It was released in 1979 with Pascal, and expanded a 48K Apple II into a
full 64K memory computer. It did not remove the upper 16K of ROM, but the
card contained 16K of RAM that was electronically parallel to the ROM.
Using "soft switches" (recall that these are memory locations that, when
read or written to, caused something internally to change) one could switch
out the ROM and switch in RAM memory. This extra memory was used to load
the Pascal disk system, and under DOS 3.2 and 3.3, to load into RAM the
version of BASIC that was not in the ROM. This was a more flexible
alternative to the Firmware Card, and opened the way to other languages
beyond BASIC for Apple II users.
Since the only way to get Apple's Language Card was to buy the entire
Pascal system ($495), it was too expensive for many users. Other companies
eventually came out with similar cards that did not require purchasing
Pascal, and some of them designed the cards with more "banks" of memory,
making 256K or more of extra memory available. Saturn Systems was one
early suppliers of the large RAM cards. Typically, each 16K bank on the
card would be switched in to the same memory space occupied by the Language
Card RAM through the use of a special softswitch.<11>
CO-PROCESSORS
Although it did not go into slot 0, another significant card for the
Apple II was the Microsoft Z-80 Softcard, which sold for around $300. It
was a co-processor card, allowing the Apple II to run software written for
the Z-80 microprocessor. The most popular operating system for the
Z-80/8080 processors was the CP/M (Control Program for Microcomputers)
system. Although the Disk II use a different method of recording data than
was used by Z-80 computers, Apple II users managed to get programs such as
the WordStar word processor transferred to the Apple CP/M system.
Microsoft worked to make it compatible with the 80-column cards that were
coming out at the time, since most CP/M software expected a screen of that
size.<3>,<12>
After the arrival of the IBM Personal Computer and its wide
acceptance by the business world, there was interest in a co-processor for
the Apple II that would run IBM software. A company called Rana, which had
been producing disk drives for the Apple II for several years, came out
with the Rana 8086/2 sometime in 1984. This was a system that plugged into
slots on a II Plus or IIe, and would allow the user to run programs written
for the IBM PC. It would also read disks formatted for that computer
(which also used a completely different data recording system than the one
used by the Apple II). One Rana owner, John Russ, wrote to A2-Central
(then called Open-Apple) to tell of his experience with it: "We also
have one of the Rana 8086/2 boxes, with two [Rana] Elite II compatible
drives and a more-or-less (mostly less) IBM-PC compatible computer inside
it. Nice idea. Terrible execution. The drives are half-high instead of
the full height drives used in the normal Elite II, and are very unreliable
for reading or writing in either the Apple or IBM format ... And this
product again shows that Rana has no knowledgeable technical folks (or they
lock them up very well). We have identified several fatal
incompatibilities with IBM programs, such as the system crashing totally if
any attempt to generate any sound (even a beep) occurs in a program, or if
inverse characters are sent to the display ... The response from Rana has
been no response at all, except that we can return the system if we want
to. Curious attitude for a company, isn't it?"<13> By August 1985 Rana
was trying to reorganize under Chapter 11, and the product was never
upgraded or fixed.
A co-processor called the ALF 8088 had limited distribution. It
worked with the CPM86 operating system (a predecessor to MS-DOS) was used
by some newer computers just before the release of the IBM PC.<14>
Even the Motorola 68000 processor used in the Macintosh came as a
co-processor for the Apple II. The Gnome Card worked on the II Plus and
IIe, but like other 68000 cards for the II, it didn't make a major impact,
with the exception of those who wanted to do cross development (create
programs for a computer using a microprocessor other than the one you are
using).
The most successful device in this category was the PC Transporter,
produced by Applied Engineering. It was originally designed by a company
in the San Jose area called The Engineering Department (TED). The founder
was Wendell Sanders, a hardware engineer who formerly had worked at Apple
and was involved in the design of the Apple III and parts of the SWIM chip
(Super Wozniak Integrated Machine) used in the IIc and IIGS. Around 1986
Applied Engineering began discussions with TED about buying the PC
Transporter to sell and market it. At that time, the board was about four
times the size it eventually became. AE's people were able to shrink a lot
of the components down to just a few custom ASIC chips. The software that
helped manage the board originally came from TED also.<15> It was finally
released in November 1987, and included a card that plugged into any of the
motherboard slots (except slot 3) and one or more IBM-style disk drives.
The PC Transporter used an 8086 processor and ran about three times as fast
as the original IBM PC. It used its own RAM memory, up to a maximum of
768K, which could be used as a RAMdisk by ProDOS (when not in PC-mode). It
used some of the main Apple memory for the interface code that lets the PC
Transporter communicate with the hardware.
The PC Transporter has undergone some minor hardware changes and
several sets of software changes (mostly bug fixes but a few new features).
The major reasons for hardware changes came about because of the
availability of cheaper RAM (the original RAM was quite expensive and
difficult to obtain). Additionally, changes were made to make the onboard
"ROM" software-based, which made it easier to distribute system upgrades
that enhanced hardware performance.<16>,<17>,<18> The major limitation for
this product has been a reluctance by Applied Engineering to match the
changes that have happened in the MS-DOS world and come out with a version
of the Transporter that used a more advanced microprocessor (80286, 386, or
486). As of 1991 this is slowly beginning to become more of a limitation
for those who wish to use both MS-DOS and Apple II software on the same
Apple II computer, since advanced software needing those more powerful
processors is beginning to be released for MS-DOS.
ACCELERATORS
The two things that all computer users eventually need (or at least
want) are more storage and faster speed. The 1 MHz speed of the 6502 and
65c02 chips is somewhat deceiving, when compared with computers that have
processors running at a speed of 20 to 40 MHz. To put things into
perspective: Since the 6502 does more than one thing with a single cycle
of the clock on the microprocessor, a 1 MHz 6502 is equivalent to a 4 MHz
8086 chip. Therefore, an Apple II with an accelerator board or chip
running at 8 MHz is equivalent to an MS-DOS computer running at 32 MHz.
One of the first accelerators for the Apple II was the SpeedDemon,
made by MCT. This board used a faster 65c02 chip, with some high-speed
internal memory that was used to actually execute the programs (since the
internal Apple II memory chips were not fast enough). In essence, it put a
second Apple II inside the one you could see, using the original one for
input and output. Another speedup board was the Accelerator IIe by Titan
Technologies (formerly Saturn Systems; they had to change their name
because it was already in use by someone else). This board worked in a
similar fashion to the SpeedDemon. Some users felt this product ran faster
than the SpeedDemon, but it depended on the application being tested. Both
boards were attached to the computer by plugging them into a slot other
than slot 0 on the motherboard.
In 1986 Applied Engineering introduced the TransWarp accelerator
board. This product has lasted in the marketplace longer than any of the
other ones, possibly because AE did far more advertising than the companies
producing the older boards. The TransWarp did the acceleration using a
different method. Instead of trying to duplicate all of the Apple II RAM
within the accelerator, they used a cache. (If you recall from the segment
on hard disk drives, a cache is a piece of memory holding frequently
accessed information). Because they used the cache, the TransWarp did not
require any high-speed RAM on the motherboard. Instead, any memory access
was also stored in the cache RAM, which was high-speed RAM. The next
time a byte was requested from RAM, the accelerator looked first into the
cache memory to see if it was there. If so, it took it (far more quickly)
from there; if not, it got it from motherboard RAM and put it into the
cache. Early TransWarp boards ran at 2.5 MHz; later versions pushed this
speed to 7 MHz (this was the top speed used by the TransWarp GS, released
in November 1988 for the Apple IIGS).
The next step in accelerator technology was to put all the components
of an accelerator board into a single chip. This happened when two rivals,
the Zip Chip and the Rocket Chip, were released. The Zip Chip was
introduced at AppleFest in May 1988, and the Rocket Chip soon after.
Running at 4 MHz, the Zip Chip was a direct replacement for the 6502 or
65c02 on the Apple II motherboard. It contained its caching RAM within the
housing for the processor, the difference being mostly in height (or
thickness) of the integrated circuit. Installing it was a bit more tricky
than simply putting a board into a slot; the 6502 had to be removed from
the motherboard with a chip puller, and the Zip Chip installed (in the
correct orientation) in its place. Software to control the speed of the
chip was included, and allowed about ten different speeds, including the
standard 1 MHz speed (some games simply were too fast to play at 4 MHz, and
software that depended on timing loops to produce music had to be slowed
down to sound right). The controlling software also let the user determine
which (if any) of the peripheral cards should be accelerated. Disk
controller cards, since they used tight timing loops to read and write
data, usually could not be accelerated, where many serial and parallel
printer and modem cards would work at the faster speed. The Zip Chip even
allowed the user to decide whether to run all sound at standard speed or at
the fast speed.
The Rocket Chip, made by Bits And Pieces Technologies, was almost
exactly the same as the Zip Chip, with a few minor exceptions. It was sold
with the ability to run programs at 5 MHz, and could be slowed down below
the 1 MHz speed (down to 0.05 MHz). Later, when Zip came out with an 8 MHz
version of their Zip chip, a 10 MHz Rocket Chip was introduced.
The rivalry between Zip Technologies and Bits And Pieces Technologies
came from a mutual blaming of theft of technical information. The Bits &
Pieces people insisted that they had done the original work on a single
chip accelerator with the Zip people, but had all the plans and
specifications taken away without their permission. Consequently, they had
to form their own company and start from scratch to design their own chip.
Zip, on the other hand, insisted that Bits & Pieces had stolen the
technology from them. The problem eventually came to court, and it was
decided that Zip Technologies was the originator of the technique and the
Rocket Chip had to stop production.
+++++++++++++++++++++++++++++++++++++
NEXT INSTALLMENT: Peripherals, cont.
+++++++++++++++++++++++++++++++++++++
NOTES
<1> Huth, Udo. (personal mail), GEnie, E-mail, Mar 1991.
<2> Spring, Michael. "Write-A.P.P.L.E.", Call-A.P.P.L.E., Apr
1984, pp. 49-50.
<3> -----. "A.P.P.L.E. Co-op Celebrates A Decade of Service",
Call-A.P.P.L.E., Feb 1988, pp. 12-27.
<4> Peterson, Craig. The Computer Store, Santa Monica, CA, Store
Information And Prices, Aug 10, 1979, p. 1.
<5> Bernsten, Jeff. GEnie, A2 Roundtable, Apr 1991, Category 2,
Topic 16.
<6> Lewellen, Tom. "Integral Data/Parallel Card Fix", PEEKing At
Call-A.P.P.L.E., Vol 2, 1979, p. 113.
<7> Golding, Val J. "Integral Data IP 225 Printer - A Review",
PEEKing At Call-A.P.P.L.E., Vol 2, 1979, p. 151.
<8> Wright, Loren. "On Buying A Printer", Micro, Aug 1981, pp.
33-35.
<9> Weishaar, Tom. "Control-I(nterface) S(tandards)", Open-Apple,
Oct 1987, pp. 3.65.
<10> -----. "Tomorrow's Apples Today", Call-A.P.P.L.E., Oct 1983,
p. 71.
<11> Weishaar, Tom. "A Concise Look At Apple II RAM", Open-Apple,
Dec 1986, p. 2.81.
<12> -----. (ads), Call-A.P.P.L.E. In Depth #1, 1981, p. 106.
<13> Weishaar, Tom. "Ask Uncle DOS", Open-Apple, Apr 1985, p. 1.32.
<14> Davidson, Keith. "The ALF 8088 Co-Processor",
Call-A.P.P.L.E., Feb 1984, p. 54.
<15> Holcomb, Jeff. GEnie, A2 Roundtable, Mar 1992, Category 11,
Topic 7.
<16> Utter, Gary. GEnie, A2 Roundtable, Dec 1991, Category 14,
Topic 12.
<17> McKay, Hugh. GEnie, A2 Roundtable, Dec 1991, Category 14,
Topic 12.
<18> Jones, Jay. GEnie, A2 Roundtable, Dec 1991, Category 14,
Topic 12.
APPLE II HISTORY
===== == =======
Compiled and written by Steven Weyhrich
(C) Copyright 1991, Zonker Software
(PART 13 -- PERIPHERALS, CONT.)
[v1.0 :: 31 Dec 91]
MODEMS
A modem is a unique peripheral device, because it
makes use of two-way communication (both sending and
receiving data to and from the computer). After the Apple
Box sold by A.P.P.L.E., one of the first commercial modems
available for the Apple II was the Micromodem II, made by
D.C. Hayes in 1979. It sold for $379, and worked at the
standard transmission speeds of the day, 110 and 300 baud.
The Micromodem was also available for the S-100 (Altair)
series of computers. Hayes' product was so popular that
their command set has become a standard for modems as they
have advanced over the years.
By the mid-1980's Apple released two modems with their
own name on them: The Apple Personal Modem 300 and Personal
Modem 1200. Both were external modems, using a direct
connection to the phone line (instead of the older acoustic
coupler), but were more expensive than similar products of
the time. By the later 1980's they were no longer in
production.
INPUT DEVICES
The number one input device for the Apple II was, of
course, the keyboard. There were expanded keyboards
available for the II and II Plus, bypassing the
uppercase-only limit. There was once even a keyboard that
had plug-in modules that would redefine specialized function
keys to make them specific for different programs. Another
company sold pressure sensitive pads that were attached to
the Apple II keyboard above the top row and could be
programmed to generate series of keypresses. The original
IIe had a socket for the addition of an external numeric
keypad, and the IIGS and later versions of the IIe had this
keypad built-in. Because of the detached keyboard in the
IIGS it was possible to select between a couple of different
versions of keyboards offered by Apple |as well as from some
third party companies.
The next most commonly used input device after the
keyboard was the set of game paddles included with every II
and II Plus. But some users needed more specialized ways to
input data to the computer. A large number of interesting
input devices were made available through the years; here
follows a brief description of some of them.
Creating pictures on the hi-res graphics screen has
always been a challenge, from 1977 until today. Using the
game paddles or a joystick is one method that could be used,
but there is some difficulty in getting accurate lines and
curves. Apple addressed this problem when they released the
Apple Graphics Tablet in the late 1970's, which sold for
about $650. This was a large flat surface, about thirty
inches square, with a grid printed on the surface. Using a
stylus attached to a wire leading to the tablet, and
appropriate software, this could be used to draw pictures on
the Apple II hi-res screen. There were two different
releases of the Apple Graphics Tablet. The original one,
which was released when the II Plus was the latest machine,
was discontinued by FCC order because of RFI (radio
frequency interference) problems. The second version, to
correct that problem, was released after the IIe was in
production. It used two DB-9 connectors to install on the
backplate of the computer, leading to the peripheral card
plugged into a slot inside. (These DB-9 connectors are the
same type used on the back of the IIc and IIGS for
connection of a joystick). Currently the Apple Graphics
Tablet is not in production.<1>
Koala Technologies has made several input devices over
the years. Their first product was the Koala Pad. Released
in 1983 and selling originally for $125, this was a small
graphics pad (about 8x6 inches) that plugged into the game
I/O socket. It was compatible with any software that used a
joystick. Using a finger or the supplied stylus, a user
could draw on the pad and produce pictures on the hi-res
screen with the supplied software or with some other
software packages.
In November 1984 Koala released Muppet Learning Keys
for $79.95. This was a device to aid preschoolers in using
a computer. It was intended to help children ages three and
over to learn letters, numbers, and colors, using the
Muppets from Sesame Street as a learning aid. The unit used
various contact surfaces to send user responses to the
computer, and it attached to the Apple II via the game I/O
port.<2>
The Gipson Light Pen System was also sold by Koala
Technologies in 1985 for $350. Using a card in slot 7, this
device used a special pen that allowed drawing directly on
the computer's monitor screen.
Other devices have been released to aid in graphics
manipulation on the Apple II. The Computer Colorworks
released the Digital Paintbrush System in 1984 for $299. It
worked on either the II Plus or IIe, and used a stylus
attached by two thin dacron lines to potentiometers within
the tablet, which tracked the position of the stylus.
Movements of the stylus (tracing over a picture) were
translated into drawings on the hi-res screen. The software
included allowed creation of curves and lines, and used
Fontrix fonts for lettering. (Fontrix was a program that
could produce detailed hi-res graphics pictures, and had
many characters styles, or fonts, available to label those
pictures). A unique feature of the Digital Paintbrush was
the ability to connect two computers using the system via a
modem and phone line and allow both users to draw pictures
that would appear on both computers simultaneously.<3>
The input device that made the most inroads in the
Apple II world was the one that was so unique to the
Macintosh: The AppleMouse II. It was released in May 1984
with a program called MousePaint (similar to the MacPaint
program that came with the original Macintosh). The
AppleMouse came with a peripheral card to plug into a slot
on the IIe or II Plus; on the IIc it just plugged into the
joystick port and the built-in hardware and firmware could
handle control of the mouse. MousePaint used the standard
hi-res graphics screen and worked only under the ProDOS
operating system, but generallygave Apple II users the
capability of doing graphics in the same way as Macintosh
users had been enjoying, as well as making it possible to
design programs that used the mouse as a pointing and input
control device.
ComputerEyes was a video acquisition system that came
out in July 1984. It allowed use of a video camera to
capture images and store them on the hi-res graphics page.
It was a slow-scan device that attached to the Apple game
I/O socket, and produced black-and-white images in about
five seconds. It worked on any Apple II with 48K,
Applesoft, and DOS 3.3. Made by Digital Vision, Inc., it
originally sold for $129.95 ($349.95 including the video
camera).<4>
MUSIC AND VOICE SYNTHESIS
Apple II's have been involved in sound from the
beginning, with the inclusion by Steve Wozniak of a speaker
so he could make sounds for an Apple II version of
"Breakout". As simple as it was, some enterprising
programmers have even managed to make this single-voice
speaker sound like two and even three different voices
(tones) simultaneously ("Electronic Duet" comes to mind).
But that was not enough for those who wanted to have better
quality music production, and so production of synthesizer
cards was in full swing by the early 1980's. Some of those
cards included the following:
ALF Music Card (ALF Products, Inc.) was strictly a
music synthesizer, with some included software to aid in
producing the music. The Mountain Music System (Mountain
Computer, Inc.) was a more advanced sixteen oscillator
(voice) digital synthesizer, also with software to control
it. Soundchaser System (Passport Designs, Inc.) was a
package that included the Mountain Music System (using slots
4 and 5), plus the Soundchaser, which was a piano-style
keyboard for music input, whose card went in slot 7. It
allowed four track recording and sound manipulation, using
the Apple II primarily as a controller. This was probably
the most advanced music hardware system available in the
days before the release of the IIGS.
The Drum-Key (made by PVI) was specifically a
percussion synthesizer. It required an external amplifier
and used included software to produce a wide variety of drum
and other percussion sounds.<5>
Beginning in the late 1970's there were several speech
synthesizers available for the Apple and other home
computers. One brand was the TextTalker, and another (made
by Mountain Hardware for $279) was the Supertalker. In the
1980's two other popular brands were the Echo II
(slot-based) and Cricket (for the modem port on the IIc)
synthesizers, made by Street Electronics. These latter
also included the ability to product other sound effects,
and some games released at the time had enhanced sound
output when the presence of those two devices was detected.
For speech reproduction, these devices usually used a method
of accepting ASCII text from the computer in the form of
"phonemes" to describe and produce voice through a built-in
speaker. The phonemes were needed because English words
have a variety of pronunciation depending on the context in
which they are used. Properly programmed, the voice
synthesizers could pronounce the word "root" to rhyme with
either "boot" or "foot". It wasn't until the IIGS came out
with the built-in capability of speech reproduction (via the
Ensoniq chip) that software making use of that feature
became available in any quantity.
ROBOTS AND DEVICE CONTROL
Although used primarily for education purposes, there
were at least two robotic devices made to work with the
Apple II. TOPO (made by Androbot, Inc.), and the Tasman
Turtle ($1000, with a smaller version called the Tot for
$300) were in use during the mid-1980's. Both used the Logo
language to control movement of the robot on the floor.
Logo has a graphics command set called "turtle" graphics to
simplify the concept for children. A small triangle on the
hi-res screen was called a "turtle", and it could be given
software commands to move forward, turn, draw, or move
without drawing. When TOPO or the Tasman Turtle were
connected to an Apple II, the Logo language could be
configured to send the same turtle graphics commands to the
physical "turtle" robot on the floor. This gave students a
concrete example of what their logo programs would do in
"drawing" a graphics picture.
Education is not the only place where robotics has
been used in an Apple II. Because of peripheral boards
called "A/D Converters" (analog/digital converters), it is
possible to take information from (for example) a wind speed
sensor and convert it into digital information. A computer
program can then take this information and send a command
signal back to another device (perhaps to activate a motor
that raises and lowers a cloth deck cover, depending on how
windy it is). Although not a "robot" in the sense that
people usually view robots, a computer-controlled device of
any kind is, strictly speaking, a robot. This is the
concept used in the popular X-10 system used in home
control. (The Introl/X-10 made by Mountain Hardware for
$279 was one of the first available for the Apple II). This
protocol for controlling electric devices in a home has been
used for years, and programs exist for the Apple II series
(including the IIc) that allow easier programming of the
X-10 devices, ranging from security systems to light timers
to lawn sprinkler systems.
MISCELLANEOUS HARDWARE
Here follows a short list of some other items that
could be found for sale in a typical issue of an Apple
computer magazine in the early 1980's:
Larger capacity disk drives were made by Lobo
Drives, including an 8 inch floppy drive and other various
higher density floppy disks.<6>
Hard disks, such as those made by Corvus Systems.
You could get a massive 10 MB for only $5,350 (well, it was
massive compared to the 143K DOS 3.3 floppy disks).
Clocks, such as the Apple Clock made by Mountain
Hardware, for $199. A clock made it possible to time and
date stamp files, and identify which version of a file was
the most recent.
RESET Key Protector, which prevented accidental
RESET on early Apple II's, was available for only $3.25 from
Special Systems Design.
DoubleDOS Plus was a Disk II interface card
modification that had a switch to allow the user to easily
switch between DOS 3.2 and DOS 3.3. It sold for $39, by
Tymac.<6>,<7>
PRINTERS
By the late 1970's and early 1980's many printers were
available for use with home computers. However, the cost
was often over $1,000, which limited the number of people
who could afford to buy one. Most printers offered 96
characters in the standard ASCII set, including both upper
and lowercase characters. The cheaper printers could only
print uppercase characters, while some of the more expensive
ones were capable of accepting programmable characters or
had built-in graphics characters.
There were two main types of printers available. One
type operated like a typewriter by striking a piece of metal
type against a ribbon and onto the paper. This type of
printer was often called an "impact" or "letter quality"
printer. It used either a type ball like IBM's Selectric
typewriters, or a wheel with spokes that radiated out from
the center, with the type characters at the end of the
spokes. This latter type of letter quality printer was also
called a "daisy wheel" printer, because the changeable print
wheels looked something like a daisy. These printers were
most commonly used by computers in businesses, as they often
cost more than $2,000 and were beyond the reach of the
average home hobbyist.
The other type of printer in common use was dot
matrix. These less expensive printers formed characters
with a series of pins in a vertical row that struck the
ribbon and produced dots on the paper. As the print head
moved across the paper, the dots were printed in patterns
that resembled (sometimes vaguely) letters and numbers. The
matrix used to form a character was usually referred to as
the number of horizontal dots by the number of vertical
dots. A 5x7 matrix, for example, used up to five dots
across and up to seven dots down. Some printers (like some
computers of the time) did not use "descenders" on the
lowercase letters that drop below the baseline ("g", "j",
"p", "q", and "y"). To print lowercase letters with
descenders often required nine or more vertical pins.
The Centronics 730 may well have been the first
"standard" printer for the Apple II (as well as for many
other microcomputers). It used a parallel cable whose pin
layout went on to also become a standard for use with
personal computers. That pin layout on parallel cable plugs
is still in use today in 1991.<8> Centronics also had
several other models, including the 737 and 739. A less
expensive printer made by Centronics, the 779, used 5x7 dot
matrix characters, and could print in sizes from 10 to 16.5
cpi (characters per inch), ranging from 60 cps (characters
per second) at 10 cpi to 100 cps at 16.5 cpi. It also had a
one-line buffer (which held up to 132 characters), but
printed a limited 64 character ASCII set, all uppercase plus
some special characters. As mentioned before, most personal
computers of the time didn't have lowercase anyway, so this
limitation wasn't necessarily a drawback. The better
printers made by Centronics had a larger matrix and could
produce true descenders on lowercase characters.<9>,<10>
A company named Trendcom made two printers that were
significant in the history of the Apple II. They had two
models, the 100 and the 200. Instead of using the mechanics
solenoids that drove pins in a print head, these were
thermal printers that needed a special heat-sensitive paper.
Their operation was very quiet, about as loud as sliding
your finger across a piece of paper. They were inexpensive
compared to other printers of the day (most of which cost
over $1,000), although the printing looked very much like
that produced by a dot-matrix printer. The Trendcom Model
100 printed 40 characters per line on paper that was about 4
1/2 inches wide. The Model 200 could print 80 columns per
line on paper 8 1/2 inches wide. Compared to the first
printer offered by Radio Shack for their TRS-80 computer
(which was also a thermal printer but used an ugly silver
paper), the Trendcom printers were very nice.
The significance of the Trendcom printer was that
Apple chose it as the first printer they released under the
Apple name. It could be programmed to control printing of
each dot in a column, and so was ideal as an inexpensive
means of printing Apple II hi-res graphics. Apple included
a special interface card and released the printer as the
"Apple Silentype" in June 1979 for $599. It was identical
to Trendcom's Model 200 except for the Apple logo in the
lower left corner of the front cover.<11> One legend
suggests that part of the popularity of this printer at
Apple stemmed from the fact that its small size allowed it
to fit under the seat of Steve Wozniak's private
airplane.<7>,<12>,<13>
Epson was another company that began early in the
business of supplying printers for personal computers, and
is one of the few that survives to this day. It got its
start in the printer business with the Epson MX-80, one of
the first dot matrix printers that sold for less than
$1,000. Popular with computer hobbyists of the time, it was
capable of printing Apple II hi-res graphics with the
optional Graphtrax ROMs. A later version of this printer,
the Epson MX-100, became available in early 1982. The
MX-100 was a wide carriage model, and could print hi-res
graphics without the need to add any special hardware.
Epson printers were unique because they had a special
feature called a "double print" mode where a line was
printed normally, then the paper was advanced 1/216 of an
inch and the same line printed again. This filled in some
gaps between dots on individual letters, and made printouts
more pleasing to the eye. Another feature used in these
printers was a "print enhancement" mode, in which the pins
hit the ribbon harder and made it possible to make multiple
copies using carbons.<10>,<14>
Integral Data Systems was also an early manufacturer
of printers. Their IDS 125 and IDS 225 printers came out in
1979 (the 225 sold for around $900).<15> These printers
used a 7x7 matrix for creating characters. The IDS 125 used
a pressure feed method (similar to the method used by
typewriters to hold paper in place), while the IDS 225 used
a tractor feed mechanism. The IDS printers had the
flexibility of being useable with either parallel or serial
interfaces (with serial speeds up to 1200 baud). It could
do plotting of dot graphics, and also had an optional
graphics character set built-in.<16>
By the late 1970's Integral Data Systems upgraded
their printers, giving them more capabilities and flashier
names. Their Paper Tiger line of printers (models 440 and
460) had an attractive typeface, and used two vertical rows
of pins in the print head, slightly offset from each other.
This produced overlapping dots to achieve a more solid
appearance. Some models could print up to 160 cps, and of
course upper and lowercase characters were supported. They
were also capable of reproducing Apple II hi-res graphics
(with the appropriate software). IDS also sold a printer
called the Prism, which could print in color using a special
multicolored ribbon.<17>
Other early printers were made by Anadex, MPI, and
Microtek.
APPLE'S PRINTERS
After the Silentype printer was released in 1979,
Apple looked for another printer that would produce better,
more permanent output than could be achieved with a thermal
printer. One of the main problems with thermal paper was
that with time the printing could fade, especially if
cellophane tape was used on the paper. The Apple Dot Matrix
Printer was released in October 1982 for $699. Made from a
modified C. Itoh printer, it was one of the first few
dot-matrix printers that sold for under $1,000. Apple
needed it as a better quality printer than the Silentype to
help promote the Apple III as a business computer. More
importantly, it was chosen by Apple because it was capable
of doing heavy-duty graphics reproduction (such as output
from the Apple Lisa computer, still in development at that
time). Known also as the Apple DMP, it used a custom ROM
programmed by Apple to control the printer's features.<18>
Because Apple was looking for as many business
solutions for its customers as it could find, they also
announced at the same time as the DMP a daisy wheel printer
called the Apple Letter Quality Printer. Costing a hefty
$2,195, and made from a modified Qume brand printer, this
printer could print at a blazing 40 cps, but did produce
very good quality output. It was released with the Lisa and
IIe in January 1983.<18>,<19>
The Apple ImageWriter was released in December 1983 as
the successor to the Apple DMP. Also made by C. Itoh, it
had a faster print speed (120 cps), and could print in eight
different pitches (character widths). It was a very
reliable, sturdy printer, and sold originally for $675.
Later, a wide carriage version whose abilities were
otherwise identical was made available. It was replaced by
the ImageWriter II in September 1985. The original
Apple DMP and the ImageWriter I came in the same beige color
as the Apple II, II Plus, and IIe. The ImageWriter II was
the same platinum color as the Apple IIGS and the newer
Macintosh computers. Styled a little differently, the
ImageWriter II could do everything the original ImageWriter
could do, plus it was capable of printing MouseText
characters and could print in color (using a special
multicolored ribbon).<19>,<20>
As part of its promotion of the Apple IIc, a new
printer was released. The Apple Scribe came in the same
"Snow White" color as the IIc and was low in cost at $299.
It was a thermal printer, but was a significant advancement
over the old Silentype. It could print on regular paper
(instead of special heat sensitive paper), and could print
in four colors. It could do this using a unique
heat-transfer method and a wax-impregnated ribbon. It could
print in a "near letter quality" mode (with overlapping
dots) at 50 cps, and a draft and graphics mode (80 cps).
Its major limitation, however, was a print quality that
overall was often not as good as some dot-matrix printers,
and a ribbon that was expensive and needed to be replaced
too often. The Scribe was eventually discontinued due to
these problems and low sales.<19>
In 1984 Hewlett-Packard introduced the LaserJet laser
printer. This was a significant breakthrough in printer
quality, and was capable of producing documents that looked
professionally typeset. Apple decided to develop its own
laser printer, and in January of 1985 released the
LaserWriter. Although not speedy printers (with best output
at four pages a minute by 1991), and very expensive (over
$2,000), they were popular with those who wanted high
quality printing. At Apple, the new LaserWriter was
supported only on the Macintosh, but since the printer did
its work through a page description language called
"PostScript", it was entirely possible for an Apple II to
print on a laser printer. It was only necessary to learn
the PostScript language, create a file that gave the
necessary commands, and send that file to the printer
through a serial interface card. Don Lancaster, long-time
Apple II supporter and hacker, wrote a series of articles
called "Ask The Guru" in the magazine Computer Shopper,
and he gave many examples of using a laser printer with an
Apple II.
Unfortunately, to this day the perception still exists
that a laser printer will not work with an Apple II, even if
it is a IIGS. This is partly because there are few software
packages for the Apple II that will produce output as
PostScript files that can be properly interpreted on a laser
printer. However, programs such as "Publish-It!" will print
to a PostScript-capable laser printer even on an Apple IIc.
All that needs to be done is to have the right cable to
connect the two devices.
One of the newest types of print technology to come to
personal computers is known as the ink-jet printer. This
type of printer works with a dot-matrix, but does not use
pins impacting a ribbon. Rather, it uses a print head that
sprays ink through as many as 64 holes in patterns to form
characters as moves across the paper. The advantage over
dot-matrix impact printers is its ability to form more solid
characters. In fact, the quality of printout with an
ink-jet printer can be almost as good as that obtained with
a laser printer. The advantage over laser printers is cost.
Where the best price for a laser printer in 1991 is still
well over $1,500, the cost of ink-jet printers is getting as
low as $500, and for some brands down to $300. The
disadvantage for Apple II users? Although it is easy to get
the printers to reproduce text, printing graphics to work
may be difficult until Apple II software packages directly
support those printers. Fortunately, most of these printers
will emulate some brands of dot-matrix printers, and if that
brand is supported by a software program, then graphics
reproduction may be possible.
Apple entered the ink-jet printer market in May 1991
when it released the Apple StyleWriter. A modification of
Canon's BubbleJet printer, this printer does excellent
reproduction of text and graphics--on a Macintosh.
Unfortunately, Apple didn't see fit to release drivers
(programs to control hardware) to make it possible to use
this printer on the IIGS or IIe. It does make use of a new
font (typeface) technology called TrueType, which makes it
possible to have a single font that can be made any size
under software control (instead of having a separate font
for each size that you might want to print). It was not
until early 1992 when a program called Pointless was made
available for the IIGS (not from Apple) that TrueType could
be used on that computer.
Although not quite a printer, the Apple Color Plotter
was released in June of 1984. It had an advantage over
printers, in that it could draw smooth lines and curves.
Using four colored pens in a rotating pen head, and
selecting them at the computer's command, the Color Plotter
worked by moving the paper up and down to draw vertical
lines, and the pen left and right to draw horizontal lines.
Control of the plotter was accomplished by sending text
commands through a serial card, and consisted of two letter
commands (DA = Draw Absolute, DR = Draw Relative, etc.)
followed by parameters. It could move the pen without
drawing, plot points, draw lines, arcs, and circles, and
print text at any location, tilt, rotation, or scale. Lines
could be drawn as solid or as patterns of dots.
Presumably this product did not take off because of
the limited need for this type of graphics, and the price.
Today, although the quality of screen and printer graphics
is greatly improved over what was available in 1984, a
plotter can still be useful in some situations. Usually,
however, the right software can reproduce drawings with a
dot matrix or laser printer in as good or better detail than
a plotter can.<21>
++++++++++++++++++++++
NEXT INSTALLMENT: DOS
++++++++++++++++++++++
NOTES
<1> Weisman, Tyler. (personal mail), GEnie, E-mail,
Aug 1991.
<2> -----. "The Marketplace", Call-A.P.P.L.E., Nov
1984, p. 41.
<3> Neibauer, Larry. "Reviews: Digital Paintbrush",
Call-A.P.P.L.E., Nov 1984, p. 36.
<4> -----. "The Marketplace", Call-A.P.P.L.E., Jul
1984, p. 61.
<5> (various). "Reviews: Music Systems For The Apple
II". Call-A.P.P.L.E., Jun 1984, pp. 17-31.
<6> -----. -----, Apple Orchard, Vol. 1, No. 1.,
Mar-Apr 1980, various.
<7> -----. (ads), Call-A.P.P.L.E. In Depth #1, 198,
p. 106.
<8> Zuchowski, Tom. GEnie, A2 Roundtable, Mar 1991,
Category 2, Topic 16.
<9> Ulm, Dennis. GEnie, A2 Roundtable, Apr 1991,
Category 2, Topic 16.
<10> Wright, Loren. "On Buying A Printer", Micro,
Aug 1981, pp. 33-35.
<11> Bernsten, Jeff. GEnie, A2 Roundtable, Apr
1991, Category 2, Topic 16
<12> -----. "A.P.P.L.E. Co-op Celebrates A Decade of
Service". Call-A.P.P.L.E., Feb 1988, pp. 12-27.
<13> Felty, Wes. GEnie, A2 Roundtable, Apr 1991,
Category 2, Topic 16.
<14> Kindall, Jerry. GEnie, A2 Roundtable, Mar
1991, Category 2, Topic 16.
<15> Peterson, Craig. The Computer Store, Santa
Monica, CA, Store Information And Prices, Aug 10,
1979, p. 1.
<16> Golding, Val. "Integral Data IP 225 Printer - A
Review", PEEKing At Call-A.P.P.L.E., Vol. 2,
1979, p. 151.
<17> Vanderpool, Tom. GEnie, A2 Roundtable, Mar &
Aug 1991, Category 2, Topic 16.
<18> Williams, Gregg. "The Lisa Computer System",
Byte, Feb 1983, p. 43.
<19> Baum, Peter. "Expanding The Unexpandable IIc",
Softalk, Jun 1984, pp. 95-97.
<20> -----. "The Marketplace", Call-A.P.P.L.E., Nov
1985, p. 50.
<21> Durkee, David. "Marketalk Reviews", Softalk,
Jun 1984, p. 120.
APPLE II HISTORY
===== == =======
Compiled and written by Steven Weyhrich
(C) Copyright 1991, Zonker Software
(PART 14 -- DOS)
[v1.0 :: 12 Jan 92]
APPLE DOS
For a computer to be useful, it must have a means of
easy storage and retrieval of data. That storage medium
must be both convenient and affordable. In the early days
of the Apple II computer, the best that they could achieve
was "affordable". The built-in cassette port was the
state of the art for personal computers back in 1977; the
Apple I computer had a cassette interface available only
as an add-on item. But, although a cassette storage system
may be inexpensive, it is not very convenient. The
simplistic cassette operating system on the Apple II (visual
examination of the mechanical index counter on the cassette
recorder to know the location of the next program) was
downright frustrating to use for many early Apple II owners.
Something better was desperately needed.
As you may recall from Part 5 of the History, in
December of 1977 Steve Wozniak began a crash effort to
develop a floppy disk drive for the Apple II computer. To
get it ready for the Consumer Electronics Show in January
1978, Wozniak and Randy Wigginton made a very simple disk
operating system that would only load files from fixed
locations off the disk in response to one-letter commands.
But it was not a true disk operating system (DOS); their
rudimentary control program would not be flexible enough for
efficient and simple use of the disk drive.
DISK SYSTEM BASICS
To create an operating system that would be both
simple to use and yet powerful enough for advanced file
manipulations, Apple had much work to do, building on the
device driver that Wozniak had written. Among other things,
it had to interface well with the BASICs in ROM on the
Apple II, and be no more complicated to use than the
cassette system. Although Woz's driver routines were
efficient in writing and reading data to and from the disk,
they could only be used from 6502 assembly language.
Designing a disk operating system from scratch is no
trivial matter. On one side is the RAM memory in the
Apple II, waiting patiently for a useful program to be
loaded and executed. On the other side of an electronic
bridge (interface card and connecting cable) is the floppy
disk and disk drive hardware itself. The control program
the Woz wrote could be compared to a narrow rope bridge
crossing a chasm; it works, but you can't carry much with
you, and it is easy to slip and fall (lose data). A
complete DOS is more like a concrete and steel bridge,
capable of carrying autos and trucks in both directions over
the chasm. Woz's "rope bridge" was a foundation, but there
was much work yet to do.
A disk drive consists of a recording head that is
mechanically moved across the surface of the floppy disk,
tracing the radius of the disk from the center to the edge.
The disk itself is spinning under the head. This is similar
to the stylus on a turntable that plays 33 RPM records
(remember those?), but the head on a disk drive can be given
a command to move to a different "track" on the spinning
disk. Also unlike the turntable, which is a "read-only"
device, the head on the disk drive can either reads bits off
or write bits onto the disk. To be able to find where data
has been stored on a disk, it is "formatted" into a known
configuration. A blank disk could be compared to empty land
that will be filled with new houses, but currently has no
streets, street signs, or house numbers. The initial
formatting (called "hard" formatting) of a blank disk is,
then, like building the streets and assigning lots for
future building. The second part of disk formatting (called
"soft" formatting), involves naming the streets, designating
addresses, and building houses.
In the case of Apple's Disk II, it was designed with
35 concentric circles ("streets") called tracks. Each track
is subdivided into 16 segments ("houses") called sectors.
Each sector can hold 256 bytes of information. In the
hardware system that Wozniak designed, the timing hole near
the center of the floppy disk was not used by the hardware
to keep track of which sector was passing the head at any
particular time. Because of that, it was necessary for the
software to identify in a different way where one sector
ended and the next sector began. A complicated method was
used of specially encoding each of the 256 bytes so they
have a standard, recognizable appearance to a program that
is controlling the disk drive, plus some other specialized
bytes that identify the start and end of a sector. Although
it did decrease somewhat the storage capacity of the disk,
the cost savings in less complicated hardware compensated
for it.
DOS 3.1 - STRUCTURE & FUNCTION WITH BASIC
With this background, let's get back to tracing the
gap between Woz's demo DOS and Apple's first official
release, DOS 3.1. Worth and Lechner in their book, "Beneath
Apple DOS", divided DOS up into four parts according to
function and location in memory. When a computer needs an
operating system, it's because there is a need to insulate
the user from the complexity of trying to control the
hardware. Consider the four parts of DOS as layers; as you
get closer to the bottom layer, you are closer to the
hardware (the raw data on the disk and direct control of the
disk drive), but you also increase greatly the difficulty of
managing it. The farther up you go, the easier it is to
manage things on the disk, but the less direct is the
control of the disk data and hardware.<1>,<2> When Wozniak
wrote his disk controller (driver) routines, he worked at
the deepest layer, directly manipulating the disk hardware
and raw data. This involved some complex timing and error
checking for reading and writing data to the disk. This
section is also where the program lies that erases the disk
and creates the sectors and their addresses. In memory,
this layer of DOS started at $B800 on a 48K Apple II.<2>,<3>
Randy Wigginton wrote a "front end" for Wozniak's
controller routines. His part could be considered a thin
layer that is part of the lowest layer of disk routines.
Together, the two layers made up what came to be known as
"RWTS", or "Read/Write Track/Sector". It could do four
things only: SEEK (to move the disk arm to the desired
track), READ (load a sector from disk into memory), WRITE
(save a sector to disk from memory), and FORMAT (discussed
above). This layer of DOS, the Disk II driver, started at
$B600.<2>,<3>
Apple contracted with an outside consultant, Bob
Shepardson, to write much of the rest of DOS (though
modifications were made Apple programmers Dick Huston and
Rick Auricchio).<4>,<5>,<6> Shepardson's group wrote the
layers (parts) of DOS that later became known as the "File
Manager" and the "Main DOS routines". The File Manager was
the next layer in memory above RWTS. It started at $AAC9 in
memory, and was responsible for twelve higher level
functions that dealt with files and the disk in general.
These functions were OPEN, CLOSE, READ, WRITE, DELETE,
CATALOG, LOCK, UNLOCK, RENAME, POSITION, INIT (format a disk
and create an empty catalog track), and VERIFY. This set of
routines, along with RWTS, would be similar to the file
PRODOS in the current 8-bit disk operating system. It
handled the disk at the file level, but knew nothing about
BASIC.<2>,<3>
The next layer of code above the File Manager
contained the Main DOS Routines. These routines started at
$9D00 in memory, and were responsible for interfacing BASIC
with the disk. This layer would be similar to the file
called BASIC.SYSTEM used today in the ProDOS system. Since
neither Integer BASIC nor Applesoft were specifically
modified to handle disk commands, this part of DOS kept a
constant look at any output PRINTed by BASIC. When a BASIC
program was running, DOS looked to see if the character
Ctrl-D (hex $04) was printed immediately after a Ctrl-M
(carriage return). If that sequence was detected, DOS
assumed that the next text printed was a command for it. If
a BASIC program was not running, then DOS examined anything
typed directly from the keyboard. If it decided that a DOS
command had been entered, it would execute that command. If
the user typed a command that DOS recognized (such as "RUN
PROGRAM" or "SAVE PROGRAM") but which resulted in a disk
error, DOS 3.1 would generate an error message. On the
other hand, if DOS did not recognize the command, it passed
it on to the active BASIC for processing.
The final, uppermost layer of DOS was not a program
code area but a set of memory areas called "buffers". One
buffer was used by DOS for each open file. These buffers
ordinarily started at $9600 in memory.
Here is an example of how the layers of DOS
interacted: When a user typed the command "LOAD PROGRAM" at
the keyboard, DOS intercepted the statement. The Main DOS
Routines determined that it was a legal DOS command. The
File Manager was called to 1) OPEN a file named "PROGRAM",
2) READ all the bytes associated with that file into memory
starting at a specific location, and then 3) CLOSE the file.
The File Manager's OPEN command in turn instructed RWTS
where to move the disk read/write head, and in what order to
read the correct tracks and sectors to find the contents of
the entire file, wherever it happened to be on the disk.
Complicated, perhaps, but the only thing the user had to
know was how to type "LOAD PROGRAM".
Finally, one piece of trivia: Why was the first DOS
released for the Apple II called "DOS 3.1" rather than "DOS
1.0"? According to Steve Wozniak, it was Bob Shepardson's
group that decided on calling it "DOS 3". It is unclear why
Shepardson decided on "3"; possibly it referred to internal
revisions done by Shepardson, or perhaps it was a
modification of some DOS routines done for another computer
that had used earlier version numbers.<2> (Note: DOS 3 was
never actually released to the public; that version
apparently had a few bugs left to fix, so "DOS 3.1" came
with the first Disk II drives shipped by Apple to their
dealers).
DOS 3.1 - MANUAL
When originally introduced with the new Disk II drive
in 1978, DOS 3.1 had very little documentation. Because the
demand for the disk drive was so great, the engineers at
Apple had worked feverishly to produce enough working drives
to begin shipping. They went out, although there was not
time to complete a real manual on how to use the disk
operating system. They did include a leaflet about some of
the commands, but there were still, obviously, complaints.
One letter to Apple president Mike Markkula made these blunt
comments: "You [expletive deleted]. I bought an Apple with
floppy and nobody, I mean nobody, in L.A. or San Diego knows
how to use the [thing] for random access files. I really
feel 'ripped off.' Everybody talks about this great manual
in the sky that is coming out soon??? ... [more expletives]!
I need this computer now in my business not next year.
[Expletive]. I hope your dog dies."<7>
It was not until the release of DOS 3.2 in February
1979 that a true reference manual was made available. It
was given the unwieldy title, "Disk II Floppy Disk Subsystem
Installation and Operating Manual", and subtitled "Apple
Intelligent Subsystems (part #030-0011-00)". It was all of
38 pages long, with weak jokes and typos, but not much else
of substance. Instruction on how to READ and WRITE text
files was given in a mere ten lines, with no programming
examples. The EXEC command was given a little more
description, but was still unclear to many users. The
manual also talked about " *3D0G ". What it didn't say
was that this meant that the user was supposed to type
"3D0G" from the Monitor prompt (to allow a return to the
active BASIC with DOS connected).<8>,<9>
DOS 3.1 - FEATURES
A catalog of the DOS 3.1 System Master disk would
produce this output:
I 007 HELLO
*I 043 APPLESOFT
I 016 ANIMALS
I 009 COLOR DEMOS
*I 004 MASTER.CREATE
*B 039 RAWDOS
*I 007 COPY
*B 007 COPY.OBJ
"HELLO" was the startup file executed when the disk
was booted. It just displayed the following:
DISK II MASTER DISKETTE VERSION 3.1
20-JUL-78
COPYRIGHT 1978 APPLE COMPUTER INC.
>_
stopping at the Integer BASIC prompt. "ANIMALS" was an
Integer program that gave an example of the use of disk
files, and "COLOR DEMOS" was a disk version of a program
that had earlier come on cassette. "MASTER CREATE" was a
program that could be used to initialize a "master" disk.
Using the binary file "RAWDOS", it executed the DOS "INIT"
command, but put a version of DOS on the newly formatted
disk that was relocatable.<10> When DOS from a "master"
disk was booted on an Apple II, it first determined what was
size of the memory, and then loaded itself into memory as
high as possible. The INIT command properly formatted a new
disk, but created what Apple called a "slave" disk; that is,
the DOS loaded from a slave disk was fixed in memory to the
same size as the computer on which DOS had been booted. In
most cases this would not be a problem. However, the
problem would surface if someone whose Apple II had only 16K
of RAM shared a disk with a friend whose computer had, say,
32K of memory. Booting that borrowed disk would make the
32K computer appear to have only 16K of RAM (since it forced
DOS to load at the highest location available to a 16K
machine). A "master" disk was more versatile, being
"intelligent" enough to adapt itself to differing memory
sizes.
The Integer BASIC file "APPLESOFT" was interesting.
It was a 43 sector file that appeared in a catalog as an
Integer BASIC program (with the "I" filetype code). If you
loaded the file and listed lines 10 through 80, there were
lines that would produce the following text: