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From: rubywand@aol.com (RUBYWAND)
Newsgroups: comp.sys.apple2.programmer
Subject: Re: Mockingboard programming
Date: 14 Feb 1996 10:06:34 -0500
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In article <victort-1302961551230001@ts-h08-15-54.ucc.su.oz.au>,
victort@extro.ucc.su.oz.au (Victor Tan) writes:

>can anyone supply information about how to make a mockingboard produce
>sound/music? I don't have any technical info about this so as much info
as
>you can supply would be greatly appeciated. Specifically, how to use it
>from 6502 assembly.
>
>Also, does anyone have any info about the different mockingboards? I see
>that some Apple II programs ask which type the user has: but what's the
>difference between them?

MockingBoard Mini-manual (Part 1)

    The Sweet Micro Systems MockingBoard comes in four 'flavors':

A. Sound I--    produces music tones and a variety of sound effects (1
channel output)
B. Speech I--  produces speech and limited sound effects (1 channel
output)
C. Sound II--   2 x Sound I on a single board (2 channels output)
D. Sound/
     Speech I-- Sound I + Speech I on a single board (2 channels output)

    MockingBoards work on Apple II's with at least 48K RAM. MB can go into
any Slot. Most programs expect it to be in Slot 4; however, it is fairly
common for a program which supports MB to ask you to enter the Slot #. 
Most for-MB products use the board for music & sound effects and will work
with boards A, C, or D. Products that use MB include Ultima III, Sky Fox,
Wiley Byte', Under Fire, Guitar Master, and Music Star.

    MB's 0.5 Watt output(s) can directly drive an 8 Ohm speaker. You can
also run the output(s) to a hi-fi amplifier.

    MB "Sound" version boards use the General Instruments AY-3-8910
Programmable Sound Generator IC. The PSG has 3 on-chip tone oscillators
(via channels A, B ,C) and a Noise Generator (NG). So, for example, the
Sound II can play up to 6 notes with 2 noises at once. 

    MB "Speech" version boards use the Votrax SC-01 Speech Synthesizer IC.
The SC-01 uses 64 phoneme sounds to produce speech. MB software lets you
adjust duration of each phoneme in 4 steps, create "rules" for custom
sounds, and speak sentences from text in BASIC programs.

    All MB versions use the 6522 Versatile Interface IC to handle board
I/O. Except for the Sound I board, there are circuit board points to which
you can add cables to utilize I/O ports not needed for Sound or Speech.

       

Rubywand
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From: rubywand@aol.com (RUBYWAND)
Newsgroups: comp.sys.apple2.programmer
Subject: Re: Mockingboard programming
Date: 14 Feb 1996 10:06:40 -0500
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victort@extro.ucc.su.oz.au (Victor Tan) writes:
>.... supply information about how to make a mockingboard produc
sound/music? .... 

MockingBoard Mini-manual (Part 2): Sound Programming

    The user can set Tone Frequency (12 bits, 4 coarse & 8 fine)* and
Amplitude (4 bits) for each channel individually. A fifth Amplitude bit
lets
you decide if a channel's Level will be "fixed" (use the Level value)  or
"variable" (i.e. follow the current Envelope pattern). You can set NG
Frequency (4 bits)*  but not level.


 Noise Freq = A2 Clock Freq/ (16 x NG value) 

    The Envelope of the combined outputs of enabled sources can be
controlled
for Period (16 bits, 8 coarse & 8 fine)**  and, roughly, for Shape (4
bits).



    The registers of the PSG are described briefly below:

Reg.    Function & Bit(s) used

00       A Freq. fine (0-7)
01       A Freq. coarse (0-3)
02       B Freq. fine (0-7)
03       B Freq. coarse (0-3)
04       C Freq. fine (0-7)
05       C Freq. coarse (0-3)
06       NG Freq. (0-4)
07       Enable =0/ Disable =1

  NG on A (5)  on B (4)  on C (3)
  Tone on A (2)  on B (1)  on C (0)
  Ex: Writing $F0 to Reg 07 plays tones A, B, C plus noise on C

08      A Level (0-3) and
     Envelope Control (4):  1 = Use Env;  0 = Use Level value

09      B Level (0-3) and ...
0A     C Level (0-3) and ...
0B     Envelope Period Fine (0-7)
0C     Envelope Period Coarse (0-7)
0D     Envelope Shape (four bits) 

  Continue (3)  0= do 1 cycle and set Level to zero
  Attack (2) 1= count up  0= count down
  Alternate (1)  1= reverse count direction each cycle
  Hold (0)  1= do 1 cycle and hold count

   To program the MB you write to the board's 6522 I/O chip(s). All
addresses reference here are for a MB Sound II (2 Output channels) in Slot
4.

$C400  ORB1  function to perform, OUT 1
$C480  ORB2  function to perform, OUT 2
$C401  ORA1  data, OUT 1
$C481  ORA2  data, OUT 2
$C402  DDRB1 data direction, OUT 1
$C482  DDRB2 data direction, OUT 2
$C403  DDRA1 data direction, OUT 1
$C483  DDRA2 data direction, OUT 2

Before sending music, etc. data to the MB you must Initialize the board's
I/O. To Initialize the 6522's: Store $FF at $C402 and the other three
DDRxx addresses. This needs to be done by your program just once.

Your program gets access to a PSG via the 6522 by using a few basic
Function codes which set the PSG's I/O control lines:
  
  Set Inactive = $04  Set PSG Reg# = $07   Write Data = $06   Reset = $00


To Write to a PSG register: Tell the PSG which Register you wish to access
(i.e. Set the "current register" #) and Write the data. This is easiest to
do with subroutines to handle the basic Functions.   

Example Subroutines (for Output Channel 1):

Set Reg #     1000:  A9 07   8D 00 C4   A9 04   8D 00 C4   60
Write Data    100B:  A9 06   8D 00 C4   A9 04   8D 00 C4   60

Notice that each Function sub ends by setting the PSG control lines to
Inactive. 
Similarly, to do a Reset (set all PSG regs to zero) ...

Reset           1016:  A9 00   8D 00 C4   A9 04   8D 00 C4   60


To put the value $55 in PSG Register 02 (Channel B Freq. fine) ....

1080: A9 02         put Reg#  in A
1082: 8D 01 C4    store A at the Data address ORA1
1085: 20 00 10     JSR to Set Reg#  (sets "current register" to Register
2) 
1088: A9 55         put the value $55 in A
108A: 8D 01 C4    store A at the Data address ORA1
108D: 20 0B 10    JSR to Write Data  ($55 goes into PSG Register 2)
1090: 60              Exit from subroutine

    Good luck!


 

Rubywand