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FORTH-83 STANDARD
A PUBLICATION OF THE FORTH STANDARDS TEAM
AUGUST 1983
FORTH-83 STANDARD
COPYRIGHT c. 1983 FORTH STANDARDS TEAM
Permission is hereby granted to reproduce this document in whole
or in part provided that such reproductions refer to the fact
that the copied material is subject to copyright by the FORTH
Standards Team. No changes or modifications may be made to the
copied material unless it is clearly indicated that such changes
were not incorporated in the original copyrighted work.
The existence of a FORTH Standard does not in any respect
preclude anyone, whether the individual has approved this
Standard or not, from implementing, marketing, purchasing or
using products, processes, or procedures not conforming to the
Standard. FORTH Standards are subject to periodic review and
users are cautioned to obtain the latest editions.
ISBN 0-914699-03-2
FORTH STANDARDS TEAM
P.O. BOX 4545
MOUNTAIN VIEW, CA 94040
USA
ii
FORTH-83 STANDARD
TABLE OF CONTENTS
1. FOREWORD ............................................... 1
2. PURPOSE ................................................ 2
3. SCOPE .................................................. 2
4. TRADEOFFS .............................................. 3
5. DEFINITIONS OF TERMS ................................... 4
6. REFERENCES ............................................. 12
7. REQUIREMENTS ........................................... 13
8. COMPLIANCE AND LABELING ................................ 15
9. USAGE .................................................. 17
10. ERROR CONDITIONS ....................................... 20
11. GLOSSARY NOTATION ...................................... 22
12. REQUIRED WORD SET ...................................... 25
13. DOUBLE NUMBER EXTENSION WORD SET ....................... 41
14. ASSEMBLER EXTENSION WORD SET ........................... 44
15. SYSTEM EXTENSION WORD SET .............................. 46
16. CONTROLLED REFERENCE WORDS ............................. 48
APPENDICES
A. FORTH STANDARDS TEAM MEMBERSHIP ................... 51
B. UNCONTROLLED REFERENCE WORDS ...................... 54
C. EXPERIMENTAL PROPOSALS ............................ 60
C.1 SEARCH ORDER SPECIFICATION AND CONTROL ....... 61
C.2 DEFINITION FIELD ADDRESS CONVERSION OPERATORS . 66
D. STANDARDS TEAM CHARTER ............................ 69
E. PROPOSAL/COMMENT FORM AND INSTRUCTIONS ............ 78
iii
FORTH-83 STANDARD
iv
1. FOREWORD
1. FOREWORD
FORTH is an integrated programming approach and computer
language. FORTH was invented by Mr. Charles Moore specifically
to increase programmer productivity in the development of
computer related applications without sacrificing machine
efficiency. FORTH is a layered environment containing the
elements of a computer language as well as those of an operating
system and a machine monitor. This extensible, layered
environment provides for highly interactive program development
and testing.
In the interests of transportability of application software
written in FORTH, standardization efforts began in the mid-1970s
by the European FORTH User's Group (EFUG). This effort resulted
in the FORTH-77 Standard. As the language continued to evolve,
an interim FORTH-78 Standard was published by the FORTH Standards
Team. Following FORTH Standards Team meetings in 1979 the FORTH-
79 Standard was published in 1980.
The FORTH Standards Team is comprised of individuals who have a
great variety of experience and technical expertise with FORTH.
The FORTH Standards Team consists of both users and implementers.
Comments, proposals, and correspondence should be mailed to:
FORTH Standards Team, P.O. Box 4545, Mountain View, CA 94040 USA.
FORTH's extensibility allows the language to be expanded and
adapted to special needs and different hardware systems. A
programmer or vendor may choose to strictly adhere with the
standard, but the choice to deviate is acknowledged as beneficial
and sometimes necessary. If the standard does not explicitly
specify a requirement or restriction, a system or application may
utilize any choice without sacrificing compliance to the standard
provided that the system or application remains transportable and
obeys the other requirements of the standard.
1
2. PURPOSE
2. PURPOSE
The purpose of this standard is to allow transportability of
FORTH-83 Standard Programs in source form among FORTH-83 Standard
Systems. A standard program shall execute equivalently on all
standard systems.
3. SCOPE
This standard shall apply to any FORTH-83 Standard Program
executing on any FORTH-83 Standard System, provided sufficient
computer resources (memory, mass storage) are available.
2
4. TRADEOFFS
4. TRADEOFFS
When conflicting choices are made, the following order guides the
Standards Team:
1) Functional correctness - known bounds, non-ambiguous;
2) Portability - repeatable results when programs are
transported among Standard Systems;
3) Simplicity;
4) Naming clarity - uniformity of expression using descriptive
rather than procedure names, i.e., [COMPILE] rather than 'C,
and ALLOT rather than DP+! ;
5) Generality;
6) Execution speed;
7) Memory compactness;
8) Compilation speed;
9) Historical continuity;
10) Pronounceability;
11) Teachability.
3
5. DEFINITIONS OF TERMS
5. DEFINITIONS OF TERMS
These are the definitions of the terms used within this Standard.
address, byte
An unsigned 16-bit number that locates an 8-bit byte in a
standard FORTH address space over the range {0..65,535}. It
may be a native machine address or a representation on a
virtual machine, locating the addr-th byte within the
virtual byte address space. Addresses are treated as
unsigned numbers. See: "arithmetic, two's complement"
address, compilation
The numerical value compiled for a FORTH word definition
which identifies that definition. The address interpreter
uses this value to locate the machine code corresponding to
each definition.
address, native machine
The natural address representation of the host computer.
address, parameter field
The address of the first byte of memory associated with a
word definition for the storage of compilation addresses (in
a colon definition), numeric data, text characters, etc.
arithmetic, two's complement
Arithmetic is performed using two's complement integers
within a field of either 16 or 32 bits as indicated by the
operation. Addition and subtraction of two's complement
integers ignore any overflow condition. This allows numbers
treated as unsigned to produce the same results as if the
numbers had been treated as signed.
block
The 1024 bytes of data from mass storage which are
referenced by block numbers in the range {0..the number of
blocks available -1}. The actual amount of data transferred
and the translation from block number to device and physical
record is a function of the implementation. See: "block
buffer" "mass storage"
block buffer
A 1024-byte memory area where a block is made temporarily
available for use. Block buffers are uniquely assigned to
blocks. See: "9.7 Multiprogramming Impact"
byte
An assembly of 8 bits. In reference to memory, it is the
storage capacity for 8 bits.
4
5. DEFINITIONS OF TERMS
character
A 7-bit number the significance of which is given by the
ASCII standard. When contained in a larger field, the
higher order bits are zero. See: "6. REFERENCES"
compilation
The action of converting text words from the input stream
into an internal form suitable for later execution. When in
the compile state, the compilation addresses of FORTH words
are compiled into the dictionary for later execution by the
address interpreter. Numbers are compiled to be placed on
the data stack when later executed. Numbers are accepted
from the input stream unsigned or negatively signed and
converted using the value of BASE . See: "number" "number
conversion" "interpreter, text"
defining word
A word that, when executed, creates a new dictionary entry
in the compilation vocabulary. The new word name is taken
from the input stream. If the input stream is exhausted
before the new name is available, an error condition exists.
Example of defining words are: : CONSTANT CREATE
definition
See: "word definition"
dictionary
A structure of word definitions in computer memory which is
extensible and grows toward higher memory addresses.
Entries are organized in vocabularies to aid location by
name. See: "search order"
display
The process of sending one or more characters to the current
output device. These characters are typically displayed or
printed on a terminal. The selection of the current output
device is system dependent.
division, floored
Integer division in which the remainder carries the sign of
the divisor or is zero, and the quotient is rounded to its
arithmetic floor. Note that, except for error conditions,
n1 n2 SWAP OVER /MOD ROT * + is identical to n1. See:
"floor, arithmetic"
Examples:
dividend divisor remainder quotient
10 7 3 1
-10 7 4 -2
10 -7 -4 -2
-10 -7 -3 1
equivalent execution
5
5. DEFINITIONS OF TERMS
A standard program will produce the same results, exclusive
of timing dependencies, when given the same inputs on any
Standard System which has sufficient resources to execute
the program. Only standard source programs are
transportable.
error condition
An exceptional condition which requires action by the system
which may be other than the expected function. Refer to the
section "10. Error Conditions".
false
A zero number represents the false state of a flag.
flag
A number that may have one of two logical states, false or
true. See: "false" "true"
floor, arithmetic
If z is any real number, then the floor of z is the greatest
integer less than or equal to z.
The floor of +.6 is 0
The floor of -.4 is -1
free field format
Numbers are converted using the value of BASE and then
displayed with no leading zeros. A trailing space is
displayed. The number of characters displayed is the
minimum number of characters, at least one, to uniquely
represent the number. See: "number conversion"
glossary
A set of explanations in natural language to describe the
corresponding computer execution of word definitions.
immediate word
A word which executes when encountered during compilation or
interpretation. Immediate words handle special cases during
compilation. See, for example, IF LITERAL ." etc.
input stream
A sequence of characters available to the system, for
processing by the text interpreter. The input stream
conventionally may be taken from the current input device
(via the text input buffer) and mass storage (via a block
buffer). BLK , >IN , TIB and #TIB specify the input stream.
Words using or altering BLK , >IN , TIB and #TIB are
responsible for maintaining and restoring control of the
input stream.
6
5. DEFINITIONS OF TERMS
The input stream extends from the offset value of >IN to the
size of the input stream. If BLK is zero the input stream
is contained within the area addressed by TIB and is #TIB
bytes long. If BLK is non-zero the input stream is
contained within the block buffer specified by BLK and is
1024 bytes long. See: "11.8 Input Text"
interpreter, address
The machine code instructions, routine or other facilities
that execute compiled word definitions containing
compilation addresses.
interpreter, text
The word definitions(s) that repeatedly accepts a word name
from the input stream, locates the corresponding compilation
address and starts the address interpreter to execute it.
Text from the input stream interpreted as a number leaves
the corresponding value on the data stack. Numbers are
accepted from the input stream unsigned or negatively signed
and converted using the value of BASE . See: "number"
"number conversion"
layers
The grouping of word names of each Standard word set to show
like characteristics. No implementation requirements are
implied by this grouping.
layer, compiler
Word definitions which add new procedures to the dictionary
or which aid compilation by adding compilation addresses or
data structures to the dictionary.
layer, devices
Word definitions which allow access to mass storage and
computer peripheral devices.
layer, interpreter
Word definitions which support vocabularies, terminal
output, and the interpretation of text from the text input
buffer or a mass storage device by executing the
corresponding word definitions.
layer, nucleus
Word definitions generally defined in machine code that
control the execution of the fundamental operations of a
virtual FORTH machine. This includes the address
interpreter.
load
Redirection of the text interpreter's input stream to be
from mass storage. This is the general method for
compilation of new definitions into the dictionary.
mass storage
7
5. DEFINITIONS OF TERMS
Storage which might reside outside FORTH's address space.
Mass storage data is made available in the form of 1024-byte
blocks. A block is accessible within the FORTH address
space in a block buffer. When a block has been indicated as
UPDATEed (modified) the block will ultimately be transferred
to mass storage.
number
When values exist within a larger field, the most-
significant bits are zero. 16-bit numbers are represented
in memory by addressing the first of two bytes at
consecutive addresses. The byte order is unspecified by
this Standard. Double numbers are represented on the stack
with the most-significant 16 bits (with sign) most
accessible. Double numbers are represented in memory by two
consecutive 16-bit numbers. The address of the least
significant 16 bits is two greater than the address of the
most significant 16 bits. The byte order within each 16-bit
field is unspecified. See: "arithmetic, two's complement"
"number types" "9.8 Numbers" "11.7 Stack Parameters"
number conversion
Numbers are maintained internally in binary and represented
externally by using graphic characters within the ASCII
character set. Conversion between the internal and external
forms is performed using the current value of BASE to
determine the digits of a number. A digit has a value
ranging from zero to the value of BASE-1. The digit with
the value zero is represented by the ASCII character "0"
(position 3/0 with the decimal equivalent of 48). This
representation of digits proceeds through the ASCII
character set to the character "(" corresponding to the
decimal value 9. For digits with a value exceeding 9, the
ASCII graphic characters beginning with the character "A"
(position 4/1 with the decimal equivalent 65) corresponding
to the decimal value 10 are used. This sequence then
continues up to and including the digit with the decimal
value 71 which is represented by the ASCII character "~"
(position 7/14 with a decimal equivalent 126). A negative
number may be represented by preceding the digits with a
single leading minus sign, the character "-".
number types
All number types consist of some number of bits. These bits
are either arbitrary or are weighted.
8
5. DEFINITIONS OF TERMS
Signed and unsigned numbers use weighted bits. Weighted
bits within a number have a value of a power of two
beginning with the rightmost (least-significant) bit having
the value of two to the zero power. This weighting
continues to the leftmost bit increasing the power by one
for each bit. For an unsigned number this weighting pattern
includes the leftmost bit; thus, for an unsigned 16-bit
number the weight of the leftmost bit is 32,768. For a
signed number this weighting pattern includes the leftmost
bit but the weight of the leftmost bit is negated; thus, for
a signed 16-bit number the weight of the leftmost bit is
-32,768. This weighting pattern for signed numbers is
called two's complement notation.
Unspecified weighted numbers are either unsigned numbers or
signed numbers; program context determines whether the
number is signed or unsigned. See: "11.7 Stack Parameters"
pictured numeric output
The use of numeric output definitions which convert
numerical values into text strings. These definitions are
used in a sequence which resembles a symbolic 'picture' of
the desired text format. Conversion proceeds from least-
significant digit to most-significant digit, and converted
characters are stored from higher memory addresses to lower.
program
A complete specification of execution to achieve a specific
function (application task) expressed in FORTH source code
form.
receive
The process of obtaining one character from the current
input device. The selection of the current input device is
system dependent.
recursion
The process of self-reference, either directly or
indirectly.
return
The means of indicating the end of text by striking a key on
an input device. The key used is system dependent. This
key is typically called "RETURN", "CARRIAGE RETURN", or
"ENTER".
screen
Textual data arranged for editing. By convention, a screen
consists of 16 lines (numbered 0 through 15) of 64
characters each. Screens usually contain program source
text, but may be used to view mass storage data. The first
byte of a screen occupies the first byte of a mass storage
block, which is the beginning point for text interpretation
during a load.
9
5. DEFINITIONS OF TERMS
search order
A specification of the order in which selected vocabularies
in the dictionary are searched. Execution of a vocabulary
makes it the first vocabulary in the search order. The
dictionary is searched whenever a word is to be located by
its name. This order applies to all dictionary searches
unless otherwise noted. The search order begins with the
last vocabulary executed and ends with FORTH , unless
altered in a system dependent manner.
source definition
Text consisting of word names suitable for compilation or
execution by the text interpreter. Such text is usually
arranged in screens and maintained on a mass storage device.
stack, data
A last in, first out list consisting of 16-bit binary
values. This stack is primarily used to hold intermediate
values during execution of word definitions. Stack values
may represent numbers, characters, addresses, boolean
values, etc.
When the name 'stack' is used alone, it implies the data
stack.
stack, return
A last in, first out list which contains the addresses of
word definitions whose execution has not been completed by
the address interpreter. As a word definition passes
control to another definition, the return point is placed on
the return stack.
The return stack may cautiously be used for other values.
string, counted
A sequence of consecutive 8-bit bytes located in memory by
their low memory address. The byte at this address contains
a count {0..255} of the number of bytes following which are
part of the string. The count does not include the count
byte itself. Counted strings usually contain ASCII
characters.
string, text
A sequence of consecutive 8-bit bytes located in memory by
their low memory address and length in bytes. Strings
usually, but not exclusively, contain ASCII characters.
When the term 'string' is used alone or in conjunction with
other words it refers to text strings.
structure, control
10
5. DEFINITIONS OF TERMS
A group of FORTH words which when executed alter the
execution sequence. The group starts and terminates with
compiler words. Examples of control structures: DO ...
LOOP DO ... +LOOP BEGIN ... WHILE ... REPEAT BEGIN ...
UNTIL IF ... THEN IF ... ELSE ... THEN See: "9.9 Control
Structures"
transportability
This term indicates that equivalent execution results when a
program is executed on other than the system on which it was
created. See: "equivalent execution"
true
A non-zero value represents the true state of a flag. Any
non-zero value will be accepted by a standard word as
'true'; all standard words return a 16-bit value with all
bits set to one when returning a 'true' flag.
user area
An area in memory which contains the storage for user
variable.
variable, user
A variable whose data storage area is usually located in the
user area. Some system variables are maintained in the user
area so that the words may be re-entrant to different users.
vocabulary
An ordered list of word definitions. Vocabularies are an
advantage in separating different word definitions that may
have the same name. More than one definition with the same
name can exist in one vocabulary. The latter is called a
redefinition. The most recently created redefinition will
be found when the vocabulary is searched.
vocabulary, compilation
The vocabulary into which new word definitions are appended.
word
A sequence of characters terminated by one blank or the end
of the input stream. Leading blanks are ignored. Words are
usually obtained via the input stream.
word definition
A named FORTH execution procedure compiled into the
dictionary. Its execution may be defined in terms of
machine code, as a sequence of compilation address, or other
compiled words.
word name
11
5. DEFINITIONS OF TERMS
The name of a word definition. Word names are limited to 31
characters and may not contain an ASCII space. If two
definitions have different word names in the same vocabulary
they must be uniquely findable when this vocabulary is
searched. See: "vocabulary" "9.5.3 EXPECT"
word set
A named group of FORTH word definitions in the Standard.
word set, assembler extension
Additional words which facilitate programming in the native
machine language of the computer which are by nature system
dependent.
word set, double number extension
Additional words which facilitate manipulation of 32-bit
numbers.
word set, required
The minimum words needed to compile and execute Standard
Programs.
word set, system extension
Additional words which facilitate the access to internal
system characteristics.
word, standard
A named FORTH procedure definition, in the Required word set
or any extension word sets, formally reviewed and accepted
by the Standards Team.
12
6. REFERENCES
6. REFERENCES
The following document is considered to be a portion of this
Standard:
American National Standard Code for Information Interchange,
___________________________________________________________
X3.4-1977 (ASCII), American National Standards Institute,
1430 Broadway, New York, NY 10018, USA.
The following documents are noted as pertinent to the FORTH-83
Standard, but are not part of this Standard.
FORTH-77, FORTH Users Group, FST-780314
FORTH-78, FORTH International Standards Team
FORTH-79, FORTH Standards Team
FORTH-83 STANDARD, Appendices, FORTH Standards Team
Webster's Collegiate Dictionary shall be used to resolve
_______________________________
conflicts in spelling and English word usage.
13
7. REQUIREMENTS
7. REQUIREMENTS
7.1 Documentation Requirements
7.1.1 Each Standard System shall be accompanied by a
statement of:
1. System dictionary space used in bytes;
2. Application dictionary space available in bytes;
3. Data space in bytes;
4. Return stack space in bytes;
5. Mass storage block ranges used by the system;
6. Mass storage block ranges available to applications;
7. Operator's terminal facilities available;
8. System action taken upon each of the general or specified
error conditions as identified in this standard.
7.1.2 Each standard program shall be accompanied by a
statement of the minimum requirements for:
1. Dictionary space in bytes;
2. Data stack space in bytes;
3. Return stack space in bytes;
4. Mass storage block ranges;
5. Operator's terminal facilities
7.2 Testing Requirements
The following host computer configuration is specified as a
minimum environment for testing against this Standard.
Applications may require different capacities.
1. 2000 bytes of memory for application dictionary;
2. Data stack of 64 bytes;
14
7. REQUIREMENTS
3. Return stack of 48 bytes;
4. Mass storage capacity of 32 blocks, numbered 0 through 31;
5. One ASCII input/output device acting as an operator's
terminal.
15
8. COMPLIANCE AND LABELING
8. COMPLIANCE AND LABELING
The FORTH Standards Team hereby specifies the requirements for
labeling of systems and applications so that the conditions for
program portability may be established.
A Standard System may use the specified labeling if it complies
with the terms of this Standard and meets the particular Word Set
definitions.
A Standard Program (application) may use the specified labeling
if it utilizes the specified Standard System according to this
Standard and executes equivalently on any such system.
In a system or application, a standard word may not be redefined
to perform a different function within the vocabulary FORTH.
FORTH Standard
A system may be labeled:
FORTH-83 Standard
if it includes all of the Required Word Set in either source or
object form and complies with the text of this Standard. After
executing "FORTH-83" the dictionary must contain all of the
Required Word Set in the vocabulary FORTH, as specified in this
Standard.
Standard Sub-set
A system may be labeled:
FORTH-83 Standard Sub-set
if it includes a portion of the Required Word Set and complies
with the remaining text of this Standard. However, no Required
Word may be present with a non-standard definition.
Standard with Extensions
A system may be labeled:
FORTH-83 Standard with <name> Standard Extension(s)
if it comprises a FORTH-83 Standard System and one or more
Standard Extension Word Set(s). For example, a designation would
be in the form:
16
8. COMPLIANCE AND LABELING
FORTH-83 Standard with Double-Number Standard Extension
Standard Program
A FORTH source program which executes equivalently on any
Standard System may be labeled:
FORTH-83 Standard Program
See: "equivalent execution" "7. REQUIREMENTS"
Standard Program with Environmental Dependencies
A program which is standard in all ways except for specific
environmentally dependent words may be labeled:
FORTH-83 Standard Program with Environmental Dependencies
if the following additional requirements are met:
1) Environmental dependencies (including hardware
dependencies) shall be factored into an isolated set of
application word definitions.
2) Each environmentally dependent word definition must be
fully documented, including all dependencies in a manner at
least as detailed as the standard words.
17
9. USAGE
9. USAGE
9.1 Words Names and Word Definitions
A Standard Program may reference only the definitions of the
Required Word Set and Standard Extensions and definitions which
are subsequently defined in terms of these words. Furthermore, A
Standard Program must use the standard words as required by any
conventions of this Standard. Equivalent execution must result
from Standard Programs.
The implementation of a Standard System may use words and
techniques outside the scope of the Standard, provided that no
program running on that system is required to use words outside
the Standard for normal operation.
If a Standard System or Standard Program redefines Standard
definitions within the FORTH vocabulary, these definitions must
comply with the Standard.
9.2 Addressable Memory
The FORTH system may share the dictionary space with the user's
application. The native addressing protocol of the host computer
is beyond the scope of this Standard.
Therefore, in a Standard Program, the user may only operate on
data which was stored by the application. No exceptions!
A Standard Program may address:
1. parameter fields of words created with CREATE , VARIABLE ,
and user defined words which execute CREATE ;
2. dictionary space ALLOTted;
3. data in a valid mass storage block buffer.
See: "9.7 Multiprogramming Impact";
4. data area of user variables;
5. text input buffer and PAD up to the amount specified as the
minimum for each area.
A Standard Program may NOT address:
1. directly into the data or return stacks;
2. into a definition's name field, link field, or code field;
18
9. USAGE
3. into a definition's parameter field if not stored by the
application.
9.3 Return Stack
A Standard Program may cautiously use the return stack with the
following restrictions:
The return stack may not be accessed inside a do-loop for values
placed on the return stack before the loop was entered. Further,
neither I nor J may be used to obtain the index of a loop if
values are placed and remain on the return stack within the loop.
When the do-loop is executed all values placed on the return
stack within that loop must be removed before LOOP , +LOOP , or
LEAVE is executed. Similarly, all values placed on the return
stack within a colon definition must be removed before the colon
definition is terminated at ; or before EXIT is executed.
9.4 Compilation
The system uses the return stack and the dictionary in a system
dependent manner during the compilation of colon definitions.
Some words use the data stack in a system dependent manner during
compilation. See: "sys (11.7)"
9.5 Terminal Input and Output
9.5.1 KEY
A Standard System must receive all valid ASCII characters. Each
KEY receives one ASCII character, with more-significant bits
environmentally dependent and might be zero. KEY must receive as
many bits as are obtainable. A Standard Program without
environmental dependencies may only use the least significant 7-
bit ASCII character received by KEY . For example: KEY 127 AND
9.5.2 EXPECT
Control characters may be processed to allow system dependent
editing of the characters prior to receipt. Therefore, a
Standard Program may not anticipated that control characters can
be received.
19
9. USAGE
9.5.3 EMIT
Because of the potential non-transportable action by terminal
devices of control characters, the use of ASCII control
characters is an environmental dependency. Each EMIT deals with
only one ASCII character. The ASCII character occupies the
least-significant 7 bits; the more-significant bits may be
environmentally dependent. Using the more-significant bits when
other than zero is an environmentally dependent usage. EMIT must
display as many bits as can be sent.
9.5.4 TYPE
Because of the potential non-transportable action by terminal
devices of control characters, the use of ASCII control
characters is an environmental dependency.
9.6 Transporting Programs Between Standard Systems
Further usage requirements are expected to be added for
transporting programs between Standard Systems.
9.7 Multiprogramming Impact
In a multiprogrammed system, Device Layer words and those words
which implicitly reference the Device Layer words may relinquish
control of the processor to other tasks. Although there is
insufficient experience to specify a standard for
multiprogramming, historical usage dictates that a programmer be
aware of the potential impact with regard to resources shared
between tasks. The only shared resources specified within the
Standard are block buffers. Therefore the address of a block
buffer returned by BLOCK or BUFFER becomes invalid during and
after the execution of any word marked by the attribute M in the
glossary or any words executing them. A block buffer is valid
only if its address is valid. See: "11.4 Attributes"
9.8 Numbers
Interpreted or compiled numbers are in the range
{-32,768..65,535}. See: "number conversion"
9.9 Control Structures
Control structures are compiled inside colon definitions.
Control structures can be nested but cannot overlap. For
additional limitations see DO .
20
10. ERROR CONDITIONS
10. ERROR CONDITIONS
10.1 Possible Actions on an Error
When an error condition occurs, a Standard System may take one or
more of the following actions:
1. ignore and continue;
2. display a message;
3. execute a particular word;
4. set interpret state and interpret a block;
5. set interpret state and begin interpretation;
6. other system dependent actions.
See: "7.1 Documentation Requirements"
10.2 General Error Conditions
The following error conditions apply in many situations. These
error conditions are listed below, but may occur at various times
and with various words.
1. input stream exhausted before encountering a required <name>
____
or delimiting character;
2. insufficient stack space or insufficient number of stack
entries during text interpretation or compilation;
3. a word not found and not a valid number, during text
interpretation or compilation;
4. compilation of incorrectly nested control structures;
5. execution of words restricted to compilation only, when not
in the compile state and while not compiling a colon
definition;
6. FORGETting within the system to a point that removes a word
required for correct execution;
7. insufficient space remaining in the dictionary;
8. a stack parameter out of range, e.g., a negative number when
a +n was specified in the glossary;
21
10. ERROR CONDITIONS
9. correct mass storage read or write was not possible.
22
11. GLOSSARY NOTATION
11. GLOSSARY NOTATION
11.1 Order
The glossary definitions are listed in ASCII alphabetical order.
11.2 Capitalization
Word names are capitalized throughout this Standard.
11.3 Stack Notation
The stack parameters input to and output from a definition are
described using the notation:
before -- after
before stack parameters before execution
after stack parameters after execution
In this notation, the top of the stack is to the right. Words
may also be shown in context when appropriate.
Unless otherwise noted, all stack notation describes exectution
time. If it applies at compile time, the line is followed by:
(compiling) .
11.4 Attributes
Capitalized symbols indicate attributes of the defined words:
C The word may only be used during compilation of a colon
definition.
I Indicates that the word is IMMEDIATE and will execute during
compilation, unless special action is taken.
M This word has a potential multiprogramming impact.
See: "9.7 Multiprogramming Impact"
U A user variable.
23
11. GLOSSARY NOTATION
11.5 Serial Numbers
When a substantive alteration to a word's definition is made or
when a new word is added, the serial number will be the last two
digits of the year of the Standard in which such change was made
(i.e., "83"). When such change is made within a Working Draft,
the number will be suffixed with the character identifying the
draft (i.e., "83A").
11.6 Pronunciation
The natural language pronunciation of word names is given in
double quotes (") where it differs from English pronunciation.
11.7 Stack Parameters
Unless otherwise stated, all references to numbers apply to 16-
bit signed integers. The implied range of values is shown as
{from..to}. The contents of an address is shown by double
braces, particularly for the contents of variables, i.e., BASE
{{2..72}}.
The following are the stack parameter abbreviations and types of
numbers used throughout the glossary. These abbreviations may be
suffixed with a digit to differentiate multiple parameters of the
same type.
24
11. GLOSSARY NOTATION
Stack Number Range in Minimum
Abbrv. Type Decimal Field
flag boolean 0=false, else=true 16
true boolean -1 (as a result) 16
false boolean 0 0
b bit {0..1} 1
char character {0..127} 7
8b 8 arbitrary bits (byte) not applicable 8
16b 16 arbitrary bits not applicable 16
n number (weighted bits) {-32,768..32,767} 16
+n positive number {0..32,767} 16
u unsigned number {0..65,535} 16
w unspecified weighted number
(n or u) {-32,768..65,535} 16
addr address (same as u) {0..65,535} 16
32b 32 arbitrary bits not applicable 32
d double number {-2,147,483,648..
2,147,483,647} 32
+d positive double number {0..2,147,483,647} 32
ud unsigned double number {0..4,294,967,265} 32
wd unspecified weighted double
number (d or ud) {-2,147,483,648..
4,294,967,295} 32
sys 0, 1, or more system
dependent stack entries not applicable na
Any other symbol refers to an arbitrary signed 16-bit integer in
the range {-32,768..32,767}, unless otherwise noted.
Because of the use of two's complement arithmetic, the signed 16-
bit number (n) -1 has the same bit representation as the unsigned
number (u) 65,535. Both of these numbers are within the set of
unspecified weighted numbers (w). See: "arithmetic, two's
complement" "number" "number types" "stack, data"
11.8 Input Text
<name>
____
An arbitrary FORTH word accepted from the input stream.
This notation refers to text from the input stream, not to
values on the data stack. See: "10.2 General Error
Conditions"
ccc
___
25
11. GLOSSARY NOTATION
A sequence of arbitrary characters accepted from the input
stream until the first occurrence of the specified
delimiting character. The delimiter is accepted from the
input stream, but is not one of the characters ccc and is
___
therefore not otherwise processed. This notation refers to
text from the input stream, not to values on the data stack.
Unless noted otherwise, the number of characters accepted
may be from 0 to 255. See: "10.2 General Error Conditions"
11.9 References to other words and definitions
Glossary definitions may refer to other glossary definitions or
to definitions of terms. Such references are made using the
expression "See:". These references provide additional
information which apply as if the information is a portion of the
glossary entry using "See:".
26
12. REQUIRED WORD SET
12. REQUIRED WORD SET
12.1 The Required Word Set Layers
The words of the Required Word Set are grouped to show like
characteristics. No implementation requirements should be
inferred from this grouping.
Nucleus layer
! * */ */MOD + +! - / /MOD 0< 0= 0> 1+ 1- 2+
2- 2/ < = > >R ?DUP @ ABS AND C! C@ CMOVE
CMOVE> COUNT D+ D< DEPTH DNEGATE DROP DUP EXECUTE
EXIT FILL I J MAX MIN MOD NEGATE NOT OR OVER PICK
R> R@ ROLL ROT SWAP U< UM* UM/MOD XOR
Device layer
BLOCK BUFFER CR EMIT EXPECT FLUSH KEY SAVE-BUFFERS
SPACE SPACES TYPE UPDATE
Interpreter layer
# #> #S #TIB ' ( -TRAILING . .( <# >BODY >IN
ABORT BASE BLK CONVERT DECIMAL DEFINITIONS FIND
FORGET FORTH FORTH-83 HERE HOLD LOAD PAD QUIT SIGN
SPAN TIB U. WORD
Compiler layer
+LOOP , ." : ; ABORT" ALLOT BEGIN COMPILE CONSTANT
CREATE DO DOES> ELSE IF IMMEDIATE LEAVE LITERAL LOOP
REPEAT STATE THEN UNTIL VARIABLE VOCABULARY WHILE [
['] [COMPILE] ]
27
12. REQUIRED WORD SET
12.2 The Required Word Set Glossary
! 16b addr -- 79 "store"
16b is stored at addr.
# +d1 -- +d2 79 "sharp"
The remainder of +d1 divided by the value of BASE is
converted to an ASCII character and appended to the output
string toward lower memory addresses. +d2 is the quotient
and is maintained for further processing. Typically used
between <# and #> .
#> 32b -- addr +n 79 "sharp-greater"
Pictured numeric output conversion is ended dropping 32b.
addr is the address of the resulting output string. +n is
the number of characters in the output string. addr and +n
together are suitable for TYPE .
#S +d -- 0 0 29 "sharp-s"
+d is converted appending each resultant character into the
pictured numeric output string until the quotient (see: # )
is zero. A single zero is added to the output string if the
number was initially zero. Typically used between <# and
#> .
#TIB -- addr U,83 "number-t-i-b"
The address of a variable containing the number of bytes in
the text input buffer. #TIB is accessed by WORD when BLK is
zero. {{0..capacity of TIB}} See: "input stream"
' -- addr M,83 "tick"
Used in the form:
' <name>
____
addr is the compilation address of <name>. An error
____
condition exists if <name> is not found in the currently
____
active search order.
( -- I,M,83 "paren"
-- (compiling)
Used in the form:
( ccc)
___
The characters ccc, delimited by ) (closing parenthesis),
___
are considered comments. Comments are not otherwise
processed. The blank following ( is not part of ccc. ( may
___
be freely used while interpreting or compiling. The number
of characters in ccc may be zero to the number of characters
___
remaining in the input stream up to the closing parenthesis.
* w1 w2 -- w3 79 "times"
w3 is the least-significant 16 bits of the arithmetic
product of w1 times w2.
28
12. REQUIRED WORD SET
*/ n1 n2 n3 -- n4 83 "times-divide"
n1 is first multiplied by n2 producing an intermediate 32-
bit result. n4 is the floor of the quotient of the
intermediate 32-bit result divided by the divisor n3. The
product of n1 times n2 is maintained as an intermediate 32-
bit result for greater precision than the otherwise
equivalent sequence: n1 n2 * n3 / . An error condition
results if the divisor is zero or if the quotient falls
outside of the range {-32,768..32,767}. See: "division,
floored"
*/MOD n1 n2 n3 -- n4 n5 83 "times-divide-mod"
n1 is first multiplied by n2 producing an intermediate 32-
bit result. n4 is the remainder and n5 is the floor of the
quotient of the intermediate 32-bit result divided by the
divisor n3. A 32-bit intermediate product is used as for
*/ . n4 has the same sign as n3 or is zero. An error
condition results if the divisor is zero or if the quotient
falls outside of the range {-32,768..32,767}. See:
"division, floored"
+ w1 w2 -- w3 79 "plus"
w3 is the arithmetic sum of w1 plus w2.
+! w1 addr -- 79 "plus-store"
w1 is added to the w value at addr using the convention for
+ . This sum replaces the original value at addr.
+LOOP n -- C,I,83 "plus-loop"
sys -- (compiling)
n is added to the loop index. If the new index was
incremented across the boundary between limit-1 and limit
then the loop is terminated and loop control parameters are
discarded. When the loop is not terminated, execution
continues to just after the corresponding DO . sys is
balanced with its corresponding DO . See: DO
, 16b -- 79 "comma"
ALLOT space for 16b then store 16b at HERE 2- .
- w1 w2 -- w3 79 "minus"
w3 is the result of subtracting w2 from w1.
-TRAILING addr +n1 -- addr +n2 79 "dash-trailing"
The character count +n1 of a text string beginning at addr
is adjusted to exclude trailing spaces. If +n1 is zero,
then +n2 is also zero. If the entire string consists of
spaces, then +n2 is zero.
. n -- M,79 "dot"
The absolute value of n is displayed in a free field format
with a leading minus sign if n is negative.
29
12. REQUIRED WORD SET
." -- C,I,83 "dot-quote"
-- (compiling)
Used in the form:
." ccc"
___
Later execution will display the characters ccc up to but
___
not including the delimiting " (close-quote). The blank
following ." is not part of ccc.
___
.( -- I,M,83 "dos-paren"
-- (compiling)
Used in the form:
.( ccc)
___
The characters ccc up to but not including the delimiting )
___
(closing parenthesis) are displayed. The blank following .(
is not part of ccc.
___
/ n1 n2 -- n3 83 "divide"
n3 is the floor of the quotient of n1 divided by the divisor
n2. An error condition results if the divisor is zero or if
the quotient falls outside of the range {-32,768..32,767}.
See: "division, floored"
/MOD n1 n2 -- n3 n4 83 "divide-mod"
n3 is the remainder and n4 the floor of the quotient of n1
divided by the divisor n2. n3 has the same sign as n2 or is
zero. An error condition results if the divisor is zero or
if the quotient falls outside of the range
{-32,768..32,767}. See: "division, floored"
0< n -- flag 83 "zero-less"
flag is true if n is less than zero (negative).
0= w -- flag 83 "zero-equals"
flag is true if w is zero.
0> n -- flag 83 "zero-greater"
flag is true if n is greater than zero.
1+ w1 -- w2 79 "one-plus"
w2 is the result of adding one to w1 according to the
operations of + .
1- w1 -- w2 79 "one-minus"
w2 is the result of subtracting one from w1 according to the
operation of - .
2+ w1 -- w2 79 "two-plus"
w2 is the result of adding two to w1 according to the
operation of + .
2- w1 -- w2 79 "two-minus"
w2 is the result of subtracting two from w1 according to the
operation of - .
30
12. REQUIRED WORD SET
2/ n1 -- n2 83 "two-divide"
n2 is the result of arithmetically shifting n1 right one
bit. The sign is included in the shift and remains
unchanged.
: -- sys M,79 "colon"
A defining word executed in the form:
: <name> ... ;
____
Create a word definition for <name> in the compilation
____
vocabulary and set compilation state. The search order is
changed so that the first vocabulary in the search order is
changed so that the first vocabulary in the search order is
replaced by the compilation vocabulary. The compilation
vocabulary is unchanged. The text from the input stream is
subsequently compiled. <name> is called a "colon
____
definition". The newly created word definition for <name>
____
cannot be found in the dictionary until the corresponding ;
or ;CODE is successfully processed.
An error condition exists if a word is not found and cannot
be converted to a number or if, during compilation from mass
storage, the input stream is exhausted before encountering ;
or ;CODE . sys is balanced with its corresponding ; . See:
"compilation" "9.4 Compilation"
; -- C,I,79 "semi-colon"
sys -- (compiling)
Stops compilation of a colon definition, allows the <name>
____
of this colon definition to be found in the dictionary, sets
interpret state and compiles EXIT (or a system dependent
word which performs an equivalent function). sys is
balanced with its corresponding : . See: EXIT : "stack,
return" "9.4 Compilation"
< n1 n2 -- flag 83 "less-than"
flag is true if n1 is less than n2.
-32678 32767 < must return true.
-32768 0 < must return true.
<# -- 79 "less-sharp"
Initialize pictured numeric output conversion. The words:
# #> #S <# HOLD SIGN
can be used to specify the conversion of a double number
into an ASCII text string stored in right-to-left order.
= w1 w2 -- flag 83 "equals"
flag is true if w1 is equal to w2.
> n1 n2 -- flag 83 "greater-than"
flag is true if n1 is greater than n2.
-32768 32767 > must return false.
-32768 0 > must return false.
31
12. REQUIRED WORD SET
>BODY addr1 -- addr2 83 "to-body"
addr2 is the parameter field address corresponding to the
compilation address addr1. See: "9.2 Addressable Memory"
>IN -- addr U,79 "to-in"
The address of a variable which contains the present
character offset within the input stream {{0..the number of
characters in the input stream}}. See: WORD
>R 16b -- C,79 "to-r"
Transfers 16b to the return stack. See "9.3 Return Stack"
?DUP 16b -- 16b 16b 79 "question-dupe"
or 0 -- 0
Duplicate 16b if it is non-zero.
@ addr -- 16b 79 "fetch"
16b is the value at addr.
ABORT 79
Clears the data stack and performs the function of QUIT .
No message is displayed.
ABORT" flag -- C,I,83 "abort-quote"
-- (compiling)
Used in the form:
flag ABORT" ccc"
___
When later executed, if flag is true the characters ccc,
___
delimited by " (close-quote), are displayed and then a
system dependent error abort sequence, including the
function of ABORT , is performed. If flag is false, the
flag is dropped and execution continues. The blank
following ABORT" is not part of ccc.
___
ABS n -- u 79 "absolute"
u is the absolute value of n. If n is -32,768 then u is the
same value. See: "arithmetic, two's complement"
ALLOT w -- 79
Allocates w bytes in the dictionary. The address of the
next available dictionary entry is updated accordingly.
AND 16b1 16b2 -- 16b3 79
16b3 is the bit-by-bit logical 'and' of 16b1 with 16b2.
BASE -- addr U,83
The address of a variable containing the current numeric
conversion radix. {{2..72}}
32
12. REQUIRED WORD SET
BEGIN -- C,I,79
-- sys (compiling)
Used in the form:
BEGIN ... flag UNTIL
or
BEGIN ... flag WHILE ... REPEAT
BEGIN marks the start of a word sequence for repetitive
execution. A BEGIN-UNTIL loop will be repeated until flag
is true. A BEGIN-WHILE-REPEAT will be repeated until flag
is false. The words after UNTIL or REPEAT will be executed
when either loop is finished. sys is balanced with its
corresponding UNTIL or WHILE . See: "9.9 Control
Structures"
BLK -- addr U,79 "b-l-k"
The address of a variable containing the number of the mass
storage block being interpreted as the input stream. If the
value of BLK is zero the input stream is taken from the text
input buffer. {{0..the number of blocks available -1}}
See: TIB "input stream"
BLOCK u -- addr M,83
addr is the address of the assigned buffer of the first byte
of block u. If the block occupying that buffer is not block
u and has been UPDATEed it is transferred to mass storage
before assigning the buffer. If block u is not already in
memory, it is transferred from mass storage into an assigned
block buffer. A block may not be assigned to more than one
buffer. If u is not an available block number, an error
condition exists. Only data within the last buffer
referenced by BLOCK or BUFFER is valid. The contents of a
block buffer must not be changed unless the change may be
transferred to mass storage.
BUFFER u -- addr M,83
Assigns a block buffer to block u. addr is the address of
the first byte of the block within its buffer. This
function is fully specified by the definition for BLOCK
except that if the block is not already in memory it might
not be transferred from mass storage. The contents of the
block buffer assigned to block u by BUFFER are unspecified.
C! 16b addr -- 79 "c-store"
The least-significant 8 bits of 16b are stored into the byte
at addr.
C@ addr -- 8b 79 "c-fetch"
8b is the contents of the byte at addr.
CMOVE addr1 addr2 u -- 83 "c-move"
Move u bytes beginning at address addr1 to addr2. The byte
at addr1 is moved first, proceeding toward high memory. If
u is zero nothing is moved.
33
12. REQUIRED WORD SET
CMOVE> addr1 addr2 u -- 83 "c-move-up"
Move the u bytes at address addr1 to addr2. The move begins
by moving the byte at (addr1 plus u minus 1) to (addr2 plus
u minus 1) and proceeds to successively lower addresses for
u bytes. If u is zero nothing is moved. (Useful for
sliding a string towards higher addresses).
COMPILE -- C,83
Typically used in the form:
: <name> ... COMPILE <namex> ... ;
When <name> is executed, the compilation address compiled
for <namex> is compiled and not executed. <name> is
typically immediate and <namex> is typically not immediate.
See: "compilation"
CONSTANT 16b -- M,83
A defining word executed in the form:
16b CONSTANT <name>
____
Creates a dictionary entry for <name> so that when <name> is
____ ____
later executed, 16b will be left on the stack.
CONVERT +d1 addr1 -- +d2 addr2 79
+d2 is the result of converting the characters within the
text beginning at addr1+2 into digits, using the value of
BASE , and accumulating each into +d1 after multiplying +d1
by the value of BASE . Conversion continues until an
unconvertible character is encounter. addr2 is the location
of the first unconvertible character.
COUNT addr1 -- addr2 +n 79
addr2 is addr1+1 and +n is the length of the counted string
at addr1. The byte at addr1 contains the byte count +n.
Range of +n is {0.255} See: "string, counted"
CR -- M,79 "c-r"
Displays a carriage-return and line-feed or equivalent
operation.
CREATE -- M,79
A defining word executed in the form:
CREATE <name>
____
Creates a dictionary entry for <name>. After <name> is
____ ____
created, the next available dictionary location is the first
byte of <name>'s parameter field. When <name> is
____ ____
subsequently executed, the address of the first byte of
<name>'s parameter field is left on the stack. CREATE does
____
not allocate space in <name>'s parameter field.
____
D+ wd1 wd2 -- wd3 79 "d-plus"
wd3 is the arithmetic sum of wd1 plus wd2.
D< d1 d2 -- flag 83 "d-less-than"
flag is true if d1 is less than d2 according to the
operation of < except extended to 32 bits.
34
12. REQUIRED WORD SET
DECIMAL -- 79
Set the input-output numeric conversion base to ten.
DEFINITIONS -- 79
The compilation vocabulary is changed to be the same as the
first vocabulary in the search order. See: "vocabulary,
compilation"
DEPTH -- +n 79
+n is the number of 16-bit values contained in the data
stack before +n was placed on the stack.
DNEGATE d1 -- d2 79 "d-negate"
d2 is the two's complement of d1.
DO w1 w2 -- C,I,83
-- sys (compiling)
Used in the form:
DO ... LOOP
or
DO ... +LOOP
Begins a loop which terminates based on control parameters.
The loop index begins at w2, and terminates based on the
limit w1. See LOOP and +LOOP for details on how the loop is
terminated. The loop is always executed at least once. For
example: w DUP DO ... LOOP executes 65,536 times. sys is
balanced with its corresponding LOOP or +LOOP . See: "9.9
Control Structures"
An error condition exists if insufficient space is available
for at least three nesting levels.
DOES> -- addr C,I,83 "does"
-- (compiling)
Defines the execution-time action of a word created by a
high-level defining word. Used in the form:
: <namex> ... <create> ... DOES> ... ;
and then
<namex> <name>
____
where <create> is CREATE or any user defined word which
executes CREATE .
Marks the termination of the defining part of the defining
word <namex> and then begins the definition of the
execution-time action for words that will later be defined
by <namex>. When <name> is later executed, the address of
____
<name>'s parameter field is placed on the stack and then the
____
sequence of words between DOES> and ; are executed.
DROP 16b -- 79
16b is removed from the stack.
DUP 16b -- 16b 16b 79 "dupe"
Duplicate 16b.
35
12. REQUIRED WORD SET
ELSE -- C,I,79
sys1 -- sys2 (compiling)
Used in the form:
flag IF ... ELSE ... THEN
ELSE executes after the true part following IF . ELSE
forces execution to continue at just after THEN . sys1 is
balanced with its corresponding IF . sys2 is balanced with
its corresponding THEN . See: IF THEN
EMIT 16b -- M,83
The least-significant 7-bit ASCII character is displayed.
SEE: "9.5.3 EMIT"
EXECUTE addr -- 79
The word definition indicated by addr is executed. An error
condition exists if addr is not a compilation address
EXIT -- C,79
Compiled within a colon definition such that when executed,
that colon definition returns control to the definition that
passed control to it by returning control to the return
point on the top of the return stack. An error condition
exists if the top of the return stack does not contain a
valid return point. May not be used within a do-loop. See:
; "stack, return" "9.3 Return Stack"
EXPECT addr +n -- M,83
Receive characters and store each into memory. The transfer
begins at addr proceeding towards higher addresses one byte
per character until either a "return" is received or until
+n characters have been transferred. No more than +n
characters will be stored. The "return" is not stored into
memory. No characters are received or transferred if +n is
zero. All characters actually received and stored into
memory will be displayed, with the "return" displaying as a
space. See: SPAN "9.5.2 EXPECT"
FILL addr u 8b -- 83
u bytes of memory beginning at addr are set to 8b. No
action is taken if u is zero.
FIND addr1 -- addr2 n 83
addr1 is the address of a counted string. The string
contains a word name to be located in the currently active
search order. If the word is not found, addr2 is the string
address addr1, and n is zero. If the word is found, addr2
is the compilation address and n is set to one of two non-
zero values. If the word found has the immediate attribute,
n is set to one. If the word is non-immediate, n is set to
minus one (true).
36
12. REQUIRED WORD SET
FLUSH -- M,83
Performs the function of SAVE-BUFFERS then unassigns all
block buffers. (This may be useful for mounting or changing
mass storage media).
FORGET -- M,83
Used in the form:
FORGET <name>
____
If <name> is found in the compilation vocabulary, delete
____
<name> from the dictionary and all words added to the
____
dictionary after <name> regardless of their vocabulary.
____
Failure to find <name> is an error condition. An error
____
condition also exists if the compilation vocabulary is
deleted. See: "10.2 General Error Conditions"
FORTH -- 83
The name of the primary vocabulary. Execution replaces the
first vocabulary in the search order with FORTH . FORTH is
initially the compilation vocabulary and the first
vocabulary in the search order. New definitions become part
of the FORTH vocabulary until a different compilation
vocabulary is established. See: VOCABULARY
FORTH-83 -- 83
Assures that a FORTH-83 Standard System is available,
otherwise an error condition exists.
HERE -- addr 79
The address of the next available dictionary location.
HOLD char -- 79
char is inserted into a pictured numeric output string.
Typically used between <# and #>.
I -- w C,79
w is a copy of the loop index. May only be used in the
form:
DO ... I ... LOOP
or
DO ... I ... +LOOP
37
12. REQUIRED WORD SET
IF flag -- C,I,79
-- sys (compiling)
Used in the form:
flag IF ... ELSE ... THEN
or
flag IF ... THEN
If flag is true, the words following IF are executed and the
words following ELSE until just after THEN are skipped. The
ELSE part is optional.
If flag is false, the words from IF through ELSE , or from
IF through THEN (when no ELSE is used), are skipped. sys is
balanced with its corresponding ELSE or THEN . See: "9.9
Control Structures"
IMMEDIATE -- 79
Marks the most recently created dictionary entry as a word
which will be executed when encountered during compilation
rather than compiled.
J -- w C,79
w is a copy of the index of the next outer loop. May only
be used within a nested DO-LOOP or DO-+LOOP in the form, for
example:
DO ... DO ... J ... LOOP ... +LOOP
KEY -- 16b M,83
The least-significant 7 bits of 16b is the next ASCII
character received. All valid ASCII characters can be
received. Control characters are not processed by the
system for any editing purpose. Characters received by KEY
will not be displayed. See: "9.5.1 KEY"
LEAVE -- C,I,83
-- (compiling)
Transfers execution to just beyond the next LOOP or +LOOP .
The loop is terminated and loop control parameters are
discarded. May only be used in the form:
DO ... LEAVE ... LOOP
or
DO ... LEAVE ... +LOOP
LEAVE may appear within other control structures which are
nested within the do-loop structure. More than one LEAVE
may appear within a do-loop. See: "9.3 Return Stack"
LITERAL -- 16b C,I,79
16b -- (compiling)
Typically used in the form:
[ 16b ] LITERAL
Compiles a system dependent operation so that when later
executed, 16b will be left on the stack.
38
12. REQUIRED WORD SET
LOAD u -- M,79
The contents of >IN and BLK , which locate the current input
stream, are saved. The input stream is then redirected to
the beginning of screen u by setting >IN to zero and BLK to
u. The screen is then interpreted. If interpretation from
screen u is not terminated explicitly it will be terminated
when the input stream is exhausted and then the contents of
>IN and BLK will be restored. An error condition exists if
u is zero. See: >IN BLK BLOCK
LOOP -- C,I,83
sys -- (compiling)
Increments the DO-LOOP index by one. If the new index was
incremented across the boundary between limit-1 and limit
the loop is terminated and loop control parameters are
discarded. When the loop is not terminated, execution
continues to just after the corresponding DO . sys is
balanced with its corresponding DO . See: DO
MAX n1 n2 -- n3 79 "max"
n3 is the greater of n1 and n2 according to the operation of
> .
MIN n1 n2 -- n3 79 "min"
n3 is the lesser of n1 and n2 according to the operation of
< .
MOD n1 n2 -- n3 83
n3 is the remainder after dividing n1 by the divisor n2. n3
has the same sign as n2 or is zero. An error condition
results if the divisor is zero or if the quotient falls
outside of the range {-32,768..32,767}. See: "division,
floored"
NEGATE n1 -- n2 79
n2 is the two's complement of n1, i.e, the difference of
zero less n1.
NOT 16b1 -- 16b2 83
16b2 is the one's complement of 16b1.
OR 16b1 16b2 -- 16b3 79
16b3 is the bit-by-bit inclusive-or of 16b1 with 16b2.
OVER 16b1 16b2 -- 16b1 16b2 16b3 79
16b3 is a copy of 16b1.
PAD -- addr 83
The lower address of a scratch area used to hold data for
intermediate processing. The address or contents of PAD may
change and the data lost if the address of the next
available dictionary location is changed. The minimum
capacity of PAD is 84 characters.
39
12. REQUIRED WORD SET
PICK +n -- 16b 83
16b is a copy of the +nth stack value, not counting +n
itself. {0..the number of elements on stack-1}
0 PICK is equivalent to DUP
1 PICK is equivalent to OVER
QUIT -- 79
Clears the return stack, sets interpret state, accepts new
input from the current input device, and begins text
interpretation. No message is displayed.
R> -- 16b C,79 "r-from"
16b is removed from the return stack and transferred to the
data stack. See: "9.3 Return Stack"
R@ -- 16b C,79 "r-fetch"
16b is a copy of the top of the return stack.
REPEAT -- C,I,79
sys -- (compiling)
Used in the form:
BEGIN ... flag WHILE ... REPEAT
At execution time, REPEAT continues execution to just after
the corresponding BEGIN . sys is balanced with its
corresponding WHILE . See: BEGIN
ROLL +n -- 83
The +nth stack value, not counting +n itself is first
removed and then transferred to the top of the stack, moving
the remaining values into the vacated position. {0..the
number of elements on the stack-1}
2 ROLL is equivalent to ROT
0 ROLL is a null operation
ROT 16b1 16b2 16b3 -- 16b2 16b3 16b1 79 "rote"
The top three stack entries are rotated, bringing the
deepest to the top.
SAVE-BUFFERS -- M,79 "save-buffers"
The contents of all block buffers marked as UPDATEed are
written to their corresponding mass storage blocks. All
buffers are marked as no longer being modified, but may
remain assigned.
SIGN n -- 83
If n is negative, an ASCII "-" (minus sign) is appended to
the pictured numeric output string. Typically used between
<# and #> .
SPACE -- M,79
Displays an ASCII space.
40
12. REQUIRED WORD SET
SPACES +n -- M,79
Displays +n ASCII spaces. Nothing is displayed if +n is
zero.
SPAN -- addr U,83
The address of a variable containing the count of characters
actually received and stored by the last execution of
EXPECT . See: EXPECT
STATE -- addr U,79
The address of a variable containing the compilation state.
A non-zero content indicates compilation is occurring, but
the value itself is system dependent. A Standard Program
may not modify this variable.
SWAP 16b1 16b2 -- 16b2 16b1 79
The top two stack entries are exchanged.
THEN -- C,I,79
sys -- (compiling)
Used in the form:
flag IF ... ELSE ... THEN
or
flag IF ... THEN
THEN is the point where execution continues after ELSE , or
IF when no ELSE is present. sys is balanced with its
corresponding IF or ELSE . See: IF ELSE
TIB -- addr 83 "t-i-b"
The address of the text input buffer. This buffer is used
to hold characters when the input stream is coming from the
current input device. The minimum capacity of TIB is 80
characters.
TYPE addr +n -- M,79
+n characters are displayed from memory beginning with the
character at addr and continuing through consecutive
addresses. Nothing is displayed if +n is zero. See:
"9.5.4 TYPE"
U. u -- M,79 "u-dot"
u is displayed as an unsigned number in a free-field format.
U< u1 u2 -- flag 83 "u-less-than"
flag is true if u1 is less than u2.
UM* u1 u2 -- ud 83 "u-m-times"
ud is the unsigned product of u1 times u2. All values and
arithmetic are unsigned.
41
12. REQUIRED WORD SET
UM/MOD ud u1 -- u2 u3 83 "u-m-divide-mod"
u2 is the remainder and u3 is the floor of the quotient
after dividing ud by the divisor u1. All values and
arithmetic are unsigned. An error condition results if the
divisor is zero or if the quotient lies outside the range
{0..65,535}. See: "floor, arithmetic"
UNTIL flag -- C,I,79
sys -- (compiling)
Used in the form:
BEGIN ... flag UNTIL
Marks the end of a BEGIN-UNTIL loop which will terminate
based on flag. If flag is true, the loop is terminated. If
flag is false, execution continues to just after the
corresponding BEGIN . sys is balanced with its
corresponding BEGIN . See: BEGIN
UPDATE -- 79
The currently valid block buffer is marked as modified.
Blocks marked as modified will subsequently be automatically
transferred to mass storage should its memory buffer be
needed for storage of a different block or upon execution of
FLUSH or SAVE-BUFFERS .
VARIABLE -- M,79
A defining word executed in the form:
VARIABLE <name>
____
A dictionary entry for <name> is created and two bytes are
____
ALLOTted in its parameter field. This parameter field is to
be used for contents of the variable. The application is
responsible for initializing the contents of the variable
which it creates. When <name> is later executed, the
____
address of its parameter field is placed on the stack.
VOCABULARY -- M,83
A defining word executed in the form:
VOCABULARY <name>
____
A dictionary entry for <name> is created which specifies a
____
new ordered list of word definitions. Subsequent execution
of <name> replaces the first vocabulary in the search order
____
with <name>. When <name> becomes the compilation vocabulary
____ ____
new definitions will be appended to <name>'s list. See:
____
DEFINITIONS "search order"
42
12. REQUIRED WORD SET
WHILE flag -- C,I,79
sys1 -- sys2 (compiling)
Used in the form:
BEGIN ... flag WHILE ... REPEAT
Selects conditional execution based on flag. When flag is
true, execution continues to just after the WHILE through to
the REPEAT which then continues execution back to just after
the BEGIN . When flag is false, execution continues to just
after the REPEAT , exiting the control structure. sys1 is
balanced with its corresponding BEGIN . sys2 is balanced
with its corresponding REPEAT . See: BEGIN
WORD char -- addr M,83
Generates a counted string by non-destructively accepting
characters from the input stream until the delimiting
character char is encountered or the input stream is
exhausted. Leading delimiters are ignored. The entire
character string is stored in memory beginning at addr as a
sequence of bytes. The string is followed by a blank which
is not included in the count. The first byte of the string
is the number of characters {0..255}. If the string is
longer than 255 characters, the count is unspecified. If
the input stream is already exhausted as WORD is called,
then a zero length character string will result.
If the delimiter is not found the value of >IN is the size
of the input stream. If the delimiter is found >IN is
adjusted to indicate the offset to the character following
the delimiter. #TIB is unmodified.
The counted string returned by WORD may reside in the "free"
dictionary area at HERE or above. Note that the text
interpreter may also use this area. See: "input stream"
XOR 16b1 16b2 -- 16b3 79 "x-or"
16b3 is the bit-by-bit exclusive-or of 16b1 with 16b2.
[ -- I,79 "left-bracket"
-- (compiling)
Sets interpret state. The text from the input stream is
subsequently interpreted. For typical usage see LITERAL .
See: ]
['] -- addr C,I,M,83 "bracket-
-- (compiling) tick"
Used in the form:
['] <name>
____
Compiles the compilation address addr of <name> as a
____
literal. When the colon definition is later executed addr
is left on the stack. An error condition exists if <name>
____
is not found in the currently active search order. See:
LITERAL
43
12. REQUIRED WORD SET
[COMPILE] -- C,I,M,79 "bracket-
-- (compiling) compile"
Used in the form:
[COMPILE] <name>
____
Forces compilation of the following word <name>. This
____
allows compilation of an immediate word when it would
otherwise have been executed.
] -- 79 "right-bracket"
Sets compilation state. The text from the input stream is
subsequently compiled. For typical usage see LITERAL .
See: [
44
13. DOUBLE NUMBER EXTENSION WORD SET
13. DOUBLE NUMBER EXTENSION WORD SET
13.1 The Double Number Extension Word Set Layers
Nucleus layer
2! 2@ 2DROP 2DUP 2OVER 2ROT 2SWAP D+ D- D0= D2/
D< D= DABS DMAX DMIN DNEGATE DU<
Device layer
none
Interpreter layer
D. D.R
Compiler layer
2CONSTANT 2VARIABLE
45
13. DOUBLE NUMBER EXTENSION WORD SET
13.2 The Double Number Extension Word Set Glossary
2! 32b addr -- 79 "two-store"
32b is stored at addr. See: "number"
2@ addr -- 32b 79 "two-fetch"
32b is the value at addr. See: "number"
2CONSTANT 32b -- M,83 "two-constant"
A defining word executed in the form:
32b 2CONSTANT <name>
____
Creates a dictionary entry for <name> so that when <name> is
____ ____
later executed, 32b will be left on the stack.
2DROP 32b -- 79 "two-drop"
32b is removed from the stack.
2DUP 32b -- 32b 32b 79 "two-dupe"
Duplicate 32b.
2OVER 32b1 32b2 -- 32b1 32b2 32b3 79 "two-over"
32b3 is a copy of 32b1.
2ROT 32b1 32b2 32b3 -- 32b2 32b3 32b1 79 "two-rote"
The top three double numbers on the stack are rotated,
bringing the third double number number to the top of the
stack.
2SWAP 32b1 32b2 -- 32b2 32b1 79 "two-swap"
The top two double numbers are exchanged.
2VARIABLE -- M,79 "two-variable"
A defining word executed in the form:
2VARIABLE <name>
____
A dictionary entry for <name> is created and four bytes are
____
ALLOTted in its parameter field. This parameter field is to
be used for contents of the variable. The application is
responsible for initializing the contents of the variable
which it creates. When <name> is later executed, the
____
address of its parameter field is placed on the stack. See:
VARIABLE
D+ wd1 wd2 -- wd3 79
See the complete definition in the Required Word Set.
D- wd1 wd2 -- wd3 79 "d-minus"
wd3 is the result of subtracting wd2 from wd1.
D. d -- M,79 "d-dot"
The absolute value of d is displayed in a free field format.
A leading negative sign is displayed if d is negative.
46
13. DOUBLE NUMBER EXTENSION WORD SET
D.R d +n -- M,83 "d-dot-r"
d is converted using the value of BASE and then displayed
right aligned in a field +n characters wide. A leading
minus sign is displayed if d is negative. If the number of
characters required to display d is greater than +n, an
error condition exists. See: "number conversion"
D0= wd -- flag 83 "d-zero-equals"
flag is true if wd is zero.
D2/ d1 -- d2 83 "d-two-divide"
d2 is the result of d1 arithmetically shifted right one bit.
The sign is included in the shift and remains unchanged.
D< d1 d2 -- flag 83
See the complete definition in the Required Word Set.
D= wd1 wd2 -- flag 83 "d-equal"
flag is true if wd1 equals wd2.
DABS d -- ud 79 "d-absolute"
ud is the absolute value of d. If d is -2,147,483,648 then
ud is the same value. See: "arithmetic, two's complement"
DMAX d1 d2 -- d3 79 "d-max"
d3 is the greater of d1 and d2.
DMIN d1 d2 -- d3 79 "d-min"
d3 is the lesser of d1 and d2.
DNEGATE d1 -- d2 79
See the complete definition in the Required Word Set.
DU< ud1 ud2 -- flag 83 "d-u-less"
flag is true if ud1 is less than ud2. Both numbers are
unsigned.
47
14. ASSEMBLER EXTENSION WORD SET
14. ASSEMBLER EXTENSION WORD SET
14.1 The Assembler Extension Word Set Layers
Nucleus layer
none
Device layer
none
Interpreter layer
ASSEMBLER
Compiler layer
;CODE CODE END-CODE
14.2 Assembler Extension Word Set Usage
Because of the system dependent nature of machine language
programming, a Standard Program cannot use CODE or ;CODE .
48
14. ASSEMBLER EXTENSION WORD SET
14.3 The Assembler Extension Word Set Glossary
;CODE -- C,I,79 "semi-colon-
sys1 -- sys2 (compiling) code"
Used in the form:
: <namex> ... <create> ... ;CODE ... END-CODE
_____ ______
Stops compilation, terminates the defining word <namex> and
_____
executes ASSEMBLER. When <namex> is executed in the form:
_____
<namex> <name>
_____ ____
to define the new <name>, the execution address of <name>
____ ____
will contain the address of the code sequence following the
;CODE in <namex>. Execution of any <name> will cause this
_____ ____
machine code sequence to be executed. sys1 is balanced with
its corresponding : . sys2 is balanced with its
corresponding END-CODE . See: CODE DOES>
ASSEMBLER -- 83
Execution replaces the first vocabulary in the search order
with the ASSEMBLER vocabulary. See: VOCABULARY
CODE -- sys M,83
A defining word executed in the form:
CODE <name> ... END-CODE
____
Creates a dictionary entry for <name> to be defined by a
____
following sequence of assembly language words. Words thus
defined are called code definitions. This newly created
word definition for <name> cannot be found in the dictionary
____
until the corresponding END-CODE is successfully processed
(see: END-CODE ). Executes ASSEMBLER . sys is balanced
with its corresponding END-CODE .
END-CODE sys -- 79 "end-code"
Terminates a code definition and allows the <name> of the
____
corresponding code definition to be found in the dictionary.
sys is balanced with its corresponding CODE or ;CODE . See:
CODE
49
15. THE SYSTEM EXTENSION WORD SET
15. THE SYSTEM EXTENSION WORD SET
15.1 The System Extension Word Set Layers
Nucleus layer
BRANCH ?BRANCH
Device layer
none
Interpreter layer
CONTEXT CURRENT
Compiler layer
<MARK <RESOLVE >MARK >RESOLVE
15.2 System Extension Word Set Usage
After BRANCH or ?BRANCH is compiled, >MARK or <RESOLVE is
executed. The addr left by >MARK is passed to >RESOLVE . The
addr left by <MARK is passed to <RESOLVE . For example:
: IF COMPILE ?BRANCH >MARK ; IMMEDIATE
: THEN >RESOLVE ; IMMEDIATE
50
15. THE SYSTEM EXTENSION WORD SET
15.3 The System Extension Word Set Glossary
<MARK -- addr C,83 "backward-mark"
Used at the destination of a backward branch. addr is
typically only used by <RESOLVE to compile a branch address.
<RESOLVE addr -- C,83"backward-resolve"
Used at the source of a backward branch after either BRANCH
or ?BRANCH . Compiles a branch address using addr as the
destination address.
>MARK -- addr C,83 "forward-mark"
Used at the source of a forward branch. Typically used
after either BRANCH or ?BRANCH . Compiles space in the
dictionary for a branch address which will later be resolved
by >RESOLVE .
>RESOLVE addr -- C,83"forward-resolve"
Used at the destination of a forward branch. Calculates the
branch address (to the current location in the dictionary)
using addr and places this branch address into the space
left by >MARK .
?BRANCH flag -- C,83"question-branch"
When used in the form: COMPILE ?BRANCH a conditional
branch operation is compiled. See BRANCH for further
details. When executed, if flag is false the branch is
performed as with BRANCH . When flag is true execution
continues at the compilation address immediately following
the branch address.
BRANCH -- C,83
When used in the form: COMPILE BRANCH an unconditional
branch operation is compiled. A branch address must be
compiled immediately following this compilation address.
The branch address is typically generated by following
BRANCH with <RESOLVE or >MARK .
CONTEXT -- addr U,79
The address of a variable which determines the dictionary
search order.
CURRENT -- addr U,79
The address of a variable specifying the vocabulary in which
new word definitions are appended.
51
16. CONTROLLED REFERENCE WORDS
16. CONTROLLED REFERENCE WORDS
The Controlled Reference Words are word definitions which,
although not required, cannot be present with a non-standard
definition in the vocabulary FORTH of a Standard System. These
words have present usage and/or are candidates for future
standardization.
--> -- I,M,79 "next-block"
-- (compilation)
Continue interpretation on the next sequential block. May
be used within a colon definition that crosses a block
boundary.
.R n +n -- M,83 "dot-r"
n is converted using BASE and then displayed right aligned
in a field +n characters wide. A leading minus sign is
displayed if n is negative. If the number of characters
required to display n is greater than +n, an error condition
exists. See: "number conversion"
2* w1 -- w2 83 "two-times"
w2 is the result of shifting w1 left one bit. A zero is
shifted into the vacated bit position.
BL -- 32 79 "b-l"
Leave the ASCII character value for space (decimal 32).
BLANK addr u -- 83
u bytes of memory beginning at addr are set to the ASCII
character value for space. No action is taken if u is zero.
C, 16b -- 83 "c-comma"
ALLOT one byte then store the least-significant 8 bits of
16b at HERE 1- .
DUMP addr u -- M,79
List the contents of u addresses starting at addr. Each
line of values may be preceded by the address of the first
value.
EDITOR -- 83
Execution replaces the first vocabulary in the search order
with the EDITOR vocabulary. See: VOCABULARY
EMPTY-BUFFERS -- M,79 "empty-buffers"
Unassign all block buffers. UPDATEed blocks are not written
to mass storage. See: BLOCK
52
16. CONTROLLED REFERENCE WORDS
END flag -- C,I,79
sys -- (compiling)
A synonym for UNTIL .
ERASE addr u -- 79
u bytes of memory beginning at addr are set to zero. No
action is taken if u is zero.
HEX -- 29
Set the numeric input-output conversion base to sixteen.
INTERPRET -- M,83
Begin text interpretation at the character indexed by the
contents of >IN relative to the block number contained in
BLK , continuing until the input stream is exhausted. If
BLK contains zero, interpret characters from the text input
buffer. See: "input stream"
K -- w C,83
w is a copy of the index of the second outer loop. May only
be used within a nested DO-LOOP or DO-+LOOP in the form, for
example:
DO ... DO ... DO ... K ... LOOP ... +LOOP ... LOOP
LIST u -- M,79
The contents of screen u are displayed. SCR is set to u.
See: BLOCK
OCTAL -- 83
Set the numeric input-output conversion base to eight.
OFFSET -- addr U,83
The address of a variable that contains the offset added to
the block number on the stack by BLOCK or BUFFER to
determine the actual physical block number.
QUERY -- M,83
Characters are received and transferred into the memory area
addressed by TIB . The transfer terminates when either a
"return" is received or the number of characters transferred
reaches the size of the area addressed by TIB . The values
of >IN and BLK are set to zero and the value of #TIB is set
to the value of SPAN . WORD may be used to accept text from
this buffer. See: EXPECT "input stream"
RECURSE -- C,I,83
-- (compiling)
Compile the compilation address of the definition being
compiled to cause the definition to later be executed
recursively.
SCR -- addr U,79 "s-c-r"
The address of a variable containing the number of the
screen most recently LISTed.
53
16. CONTROLLED REFERENCE WORDS
SP@ -- addr 79 "s-p-fetch"
addr is the address of the top of the stack just before SP@
was executed.
THRU u1 u2 -- M,83
Load consecutively the blocks from u1 through u2.
U.R u +n -- M,83 "u-dot-r"
u is converted using the value of BASE and then displayed as
an unsigned number right aligned in a field +n characters
wide. If the number of characters required to display u is
greater than +n, an error condition exists. See: "number
conversion"
54
A. STANDARDS TEAM MEMBERSHIP
APPENDIX A. STANDARDS TEAM MEMBERSHIP
A.1 Standard Team Membership: Members
The following is a list in alphabetical order of the people who
are FORTH Standards Team Members. These names are provided to
indicate the texture and make-up of the team itself. Where
appropriate, the official capacity of individuals is also
indicated.
Paul Bartholdi, Sauverny, Switzerland
Robert Berkey, Palo Alto, California USA Treasurer
David Boulton, Redwood City, California USA
John Bumgarner, Morgan Hill, California USA
Don Colburn, Rockville, Maryland USA
James T. Currie, Jr., Blacksburg, Virginia USA
Thomas B. Dowling, Lowell, Massachusetts USA
William S. Emery, Malibu, California USA
Lawrence P. Forsley, Rochester, New York USA
Kim R. Harris, Palo Alto, California USA Referee
John S. James, Los Gatos, California USA
Guy M. Kelly, La Jolla, California USA Chair
Thea Martin, Rochester, New York USA
Michael McNeil, Scotts Valley, California USA
Robert E. Patten, Modesto, California USA
Michael Perry, Berkeley, California USA
David C. Petty, Cambridge, Massachusetts USA
William F. Ragsdale, Hayward, California USA
Elizabeth D. Rather, Hermosa Beach, California USA
Dean Sanderson, Hermosa Beach, California USA Referee
Klaus Schleisiek, Hamburg, W-Germany
George W. Shaw II, Hayward, California USA Referee
Robert L. Smith, Palo Alto, California USA Secretary
Michael K. Starling, Elkview, West Virginia USA
John K. Stevenson, Portland, Oregon USA
Glenn S. Tenney, San Mateo, California USA Referee
55
A. STANDARDS TEAM MEMBERSHIP
A.2 FORTH Standards Team Sponsors
The following is a list in alphabetical order of individuals and
organizations who have contributed funds and other assistance to
aid the word of the FST and deserve recognition for their
involvement. FST sponsors have no duties or responsibilities in
the FST, but they receive copies of proposals and comments
considered at a formal meeting, and drafts and adopted standards
prepared as a result of that meeting.
Creative Solutions Inc., 4801 Randolph Rd., Rockville, MD 20852
USA
Fantasia Systems Inc., 1059 Alameda de las Pulgas, Belmont, CA
94002 USA
FORTH, Inc., 2309 Pacific Coast Highway, Hermosa Beach, CA 90254
USA
FORTH Interest Group Inc., P.O. Box 1105, San Carlos, CA 94070
USA
Forthright Enterprises, P.O. Box 50911, Palo Alto, CA 94020 USA
Glen Haydon Enterprises, Box 439 Rt. 2, La Honda, CA 94020 USA
John K. Gotwals, W. Lafayette, IN USA
John D. Hall, Oakland, CA USA
Hartronix, Inc., 1201 N. Stadem, Tempe, AZ 85281 USA
Hewlett-Packard Corvallis Div., 1000 NE Circle Blvd., Corvallis,
OR 97330 USA
Information Unlimited Software, Inc., 2401 Marinship, Sausalito,
CA 94965 USA
Henry H. Laxen, 1259 Cornell Avenue, Berkeley, CA 94705 USA
Laxen & Harris, Inc.
George B. Lyons, 280 Henderson Street, Jersey Cit, NJ 07302 USA
C. Kevin McCabe, Chicago, IL USA
MicroMotion, 12077 Wilshire Blvd #506, Los Angeles, CA 90025 USA
Bruce R. Montague, Monterey, CA USA
Mountain View Press, P.O. Box 4659, Mountain View, CA 94040 USA
56
A. STANDARDS TEAM MEMBERSHIP
Michael A. Perry, Berkeley, CA USA
Robert Berkey Services, 2334 Dumbarton Ave., Palo Alto, CA 94303
USA
Royal Greenwich Observatory, Herstmonsioux Castle, Eastbourne,
England
Shaw Laboratories, Ltd., 24301 Southland Drive #216, Hayward, CA
94545 USA
Sygnetron Protection Systems, Inc., 2103 Greenspring, Timonium,
MD 21093 USA
Telelogic Inc., 196 Broadway, Cambridge, MA 02139 USA
UNISOFT, P.O. Box 2644, New Carrollton, MD 20784 USA
57
B. UNCONTROLLED REFERENCE WORDS
APPENDIX B. UNCONTROLLED REFERENCE WORDS
The Uncontrolled Reference Word Set contains glossary definitions
which are included for public reference of words that have past
or present usage and/or are candidates for future
standardization. No recommendation is made that these words be
included in a system.
No restrictions are placed on the definition or usage of
uncontrolled words. However, use of these names for procedures
differing from the given definitions is discouraged.
!BITS 16b1 addr 16b2 -- "store-bits"
Store the value of 16b1 masked by 16b2 into the equivalent
masked part of the contents of addr, without affecting bits
outside the mask.
** n1 n2 -- n3 "power"
n3 is the value of n1 to the power n2.
+BLOCK w -- u "plus-block"
u is the sum of w plus the number of the block being
interpreted.
-' -- addr false "dash-tick"
-- true
Used in the form:
-' <name>
____
Leave the parameter field of <name> beneath zero (false) if
____
<name> can be found in the search order; leave only true if
____
not found.
-MATCH addr1 +n1 addr2 +n2 -- addr3 flag "dash-match"
Attempt to find the +n2-length text string beginning at
addr2 somewhere in the +n1-length text string beginning at
addr1. Return the last+1 address addr3 of the match point
and a flag which is zero if a match exists.
-TEXT addr1 +n1 addr2 -- n2 "dash-text"
Compare two strings over the length +n1 beginning at addr1
and addr2. Return zero if the strings are equal. If
unequal, return n2, the difference between the last
characters compared: addr1(i) - addr2(i).
58
B. UNCONTROLLED REFERENCE WORDS
/LOOP +n -- C,I "up-loop"
sys -- (compiling)
A do-loop terminating word. The loop index is incremented
by the positive value +n. If the unsigned magnitude of the
resultant index is greater than the limit, then the loop is
terminated, otherwise execution returns to the corresponding
DO . The comparison is unsigned magnitude. sys is balanced
with its corresponding DO . See: DO
1+! addr -- "one-plus-store"
Add one to the 16-bit contents at addr.
1-! addr -- "one-minus-store"
Subtract one from the 16-bit contents at addr.
;: -- addr C,I"semi-colon-colon"
Used to specify a new defining word:
: <namex> <name>
____
When <namex> is executed, it creates an entry for the new
word <name>. Later execution of <name> will execute the
____ ____
sequence of words between ;: and ; , with the address of the
first (if any) parameters associated with <name> on the
____
stack.
;S -- Interpret only"semi-s"
Stop interpretation of a block.
<> w1 w2 -- flag "not-equal"
flag is true if w1 is not equal to w2.
<BUILDS -- "builds"
Used in conjunction with DOES> in defining words, in the
form:
: <namex> ... <BUILDS ... DOES> ... ;
and then:
<namex> <name>
____
When <namex> executes, <BUILDS creates a dictionary entry
for the new <name>. The sequence of words between <BUILDS
____
and DOES> established a parameter field for <name>. When
____
<name> is later executed, the sequence of words following
____
DOES> will be executed, with the parameter field address of
<name> on the data stack.
____
<CMOVE addr1 addr2 u -- "reverse-c-move"
A synonym for CMOVE> .
>< 16b1 -- 16b2 "byte-swap"
Swap the high and low bytes within 16b1.
>MOVE< addr1 addr2 u -- "byte-swap-move"
Move u bytes beginning at addr1 to the memory beginning at
addr2. During this move, the order of each byte pair is
reversed.
59
B. UNCONTROLLED REFERENCE WORDS
@BITS addr 16b1 -- 16b2 "fetch-bits"
Return the 16-bits at addr masked by 16b1.
AGAIN -- C,I
sys -- (compiling)
Effect an unconditional jump back to the start of a BEGIN-
AGAIN loop. sys is balanced with its corresponding BEGIN .
See: BEGIN
ASCII -- char I,M "as-key"
-- (compiling)
Used in the form:
ASCII ccc
___
where the delimiter of ccc is a space. char is the ASCII
___
character value of the first character in ccc. If
___
interpreting, char is left on the stack. If compiling,
compile char as a literal so that when the colon definition
is later executed, char is left on the stack.
ASHIFT 16b1 n -- 16b2 "a-shift"
Shift the value 16b1 arithmetically n bits left if n is
positive, shifting zeros into the least significant bit
positions. If n is negative, 16b1 is shifted right; the
sign is included in the shift and remains unchanged.
B/BUF -- 1024 "bytes-per-buffer"
A constant leaving 1024, the number of bytes per block
buffer.
BELL --
Activate a terminal bell or noise-maker as appropriate to
the device in use.
CHAIN -- M
Used in the form:
CHAIN <name>
____
Connect the CURRENT vocabulary to all definitions that might
be entered into the vocabulary <name> in the future. The
____
CURRENT vocabulary may not be FORTH or ASSEMBLER . Any
given vocabulary may only be chained once, but may be the
object of any number of chainings. For example, every user-
defined vocabulary may include the sequence:
CHAIN FORTH
CONTINUED u -- M
Continue interpretation at block u.
CUR -- addr
A variable pointing to the physical record number before
which the tape is currently positioned. REWIND sets CUR=1.
DBLOCK ud -- addr M "d-block"
Identical to BLOCK but with a 32-bit block unsigned number.
60
B. UNCONTROLLED REFERENCE WORDS
DPL -- addr U "d-p-l"
A variable containing the number of places after the
fractional point for input conversion.
FLD -- addr U "f-l-d"
A variable pointing to the field length reserved for a
number during output conversion.
H. u -- M "h-dot"
Output u as a hexadecimal integer with one trailing blank.
The current base is unchanged.
I' -- w C "i-prime"
Used within a colon definition executed only from within a
do-loop to return the corresponding loop index.
IFEND Interpret only"if-end"
Terminate a conditional interpretation sequence begun by
IFTRUE .
IFTRUE flag -- Interpret only "if-true"
Begin an:
IFTRUE ... OTHERWISE ... IFEND
conditional sequence. These conditional words operated
like:
IF ... ELSE ... THEN
except that they cannot be nested, and are to be used only
during interpretation. In conjunction with the words [ and
] the words [ and ] they may be used within a colon
definition to control compilation, although they are not to
be compiled.
INDEX u1 u2 -- M
Print the first line of each screen over the range {u1..u2}.
This displays the first line of each screen of source text,
which conventionally contains a title.
LAST -- addr U
A variable containing the address of the beginning of the
last dictionary entry made, which may not yet be a complete
or valid entry.
LINE +n -- addr M
addr is the address of the beginning of line +n for the
screen whose number is contained in SCR . The range of +n
is {0..15}.
LINELOAD +n u -- "line-load"
Begin interpretation at line +n of screen u.
61
B. UNCONTROLLED REFERENCE WORDS
LOADS u -- M
A defining word executed in the form:
u LOADS <name>
____
When <name> is subsequently executed, block u will be
____
loaded.
MAP0 -- addr "map-zero"
A variable pointing to the first location in the tape map.
MASK n -- 16b
16b is a mask of n most-significant bits if n is positive,
or n least-significant bits if n is negative.
MOVE addr1 addr2 u --
The u bytes at address addr1 are moved to address addr2.
The data are moved such that the u bytes remaining at
address addr2 are the same data as was originally at address
addr1. If u is zero nothing is moved.
MS +n -- M "m-s"
Delay for approximately +n milliseconds.
NAND 16b1 16b2 -- 16b3
16b3 is the one's complement of the logical AND of 16b1 with
16b2.
NOR 16b1 16b2 -- 16b3
16b3 is the one's complement of the logical OR of 16b1 with
16b2.
NUMBER addr -- d
Convert the count and character string at addr, to a signed
32-bit integer, using the value of BASE . If numeric
conversion is not possible, an error condition exists. The
string may contain a preceding minus sign.
O. u -- M "o-dot"
Print u in octal format with one trailing blank. The value
in BASE is unaffected.
OTHERWISE -- Interpret only
An interpreter-level conditional word. See: IFTRUE
PAGE -- M
Clear the terminal screen or perform a form-feed action
suitable to the output device currently active.
READ-MAP -- M "read-map"
Read to the next file mark on tape constructing a
correspondence table in memory (the map) relating physical
block position to logical block number. The tape should
normally be rewound to its load point before executing READ-
MAP .
62
B. UNCONTROLLED REFERENCE WORDS
REMEMBER -- M
A defining word executed in the form:
REMEMBER <name>
____
Defines a word which, when executed, will cause <name> and
____
all subsequently defined words to be deleted from the
dictionary. <name> may be compiled into and executed from a
____
colon definition. The sequence
DISCARD REMEMBER DISCARD
provides a standardized preface to any group of transient
word definitions.
REWIND -- M
Rewind the tape to its load point, setting CUR equal to one.
ROTATE 16b1 n -- 16b2
Rotate 16b1 left n bits if n is positive, right n bits if n
is negative. Bits shifted out of one end of the cell are
shifted back in at the opposite end.
S0 -- addr U "s-zero"
A variable containing the address of the bottom of the
stack.
SET 16b addr -- M
A defining word executed in the form:
16b addr SET <name>
____
Defines a word <name> which, when executed, will cause the
____
value 16b to be stored at addr.
SHIFT 16b1 n -- 16b2
Logical shift 16b1 left n bits if n is positive, right n
bits if n is negative. Zeros are shifted into vacated bit
positions.
TEXT char -- M
Accept characters from the input stream, as for WORD , into
PAD , blank-filling the remainder of PAD to 84 characters.
USER +n -- M
A defining word executed in the form:
+n USER <name>
____
which creates a user variable <name>. +n is the offset
____
within the user area where the value for <name> is stored.
____
Execution of <name> leaves its absolute user area storage
____
address.
WORDS -- M
List the word names in the first vocabulary of the currently
active search order.
63
B. UNCONTROLLED REFERENCE WORDS
\LOOP +n -- C,I "down-loop"
sys -- (compiling)
A do-loop terminating word. The loop index is decremented
by the positive value +n. If the unsigned magnitude of the
resultant index is less than or equal to the limit, then the
loop is terminated, otherwise execution returns to the
corresponding DO . The comparison is unsigned. sys is
balanced with its corresponding DO . See: DO
64
C. EXPERIMENTAL PROPOSALS
APPENDIX C. EXPERIMENTAL PROPOSALS
Since FORTH is an extensible language and subject to evolution,
the Standard contains a section describing experimental
proposals. FORTH users are encouraged to study, implement, and
try these proposals to aid in the analysis of and the decision
for or against future adoption into the Standard. Readers are
cautioned that these proposals contain opinions and conclusions
of the authors of the proposals and that these proposals may
contain non-standard source code.
65
C. EXPERIMENTAL PROPOSALS
SEARCH ORDER SPECIFICATION AND CONTROL
WILLIAM F. RAGSDALE
1 INTRODUCTION
The method of selecting the order in which the dictionary is
searched has grown from unchained vocabularies to the present use
of chained vocabularies. Many techniques are in use for
specification of the sequence in which multiple vocabularies may
be searched. In order to offer generality and yet get precision
in specification, this proposal is offered.
2 DESCRIPTION
The following functions are required:
1. Two search orders exist. CONTEXT is the group of
vocabularies searched during interpretation of text from the
input stream. CURRENT is the single vocabulary into which
new definitions are compiled, and from which FORGET
operates.
2. Empty CONTEXT to a minimum number of system words. These
are just the words to further specify the search order.
3. Add individual vocabularies into CONTEXT. The most recently
added is searched first.
4. Specify which single vocabulary will become CURRENT.
The following optional functions aid the user:
1. Display the word names of the first vocabulary in the
CONTEXT search order.
2. Display the vocabulary names comprising CURRENT and CONTEXT
search orders.
66
C. EXPERIMENTAL PROPOSALS
3 ADVANTAGES
Use over the past year has demonstrated that the proposed
methods may emulate the vocabulary selection of all other
systems. The order is explicit by execution, may be interpreted
and compiled, and is obvious from the declaration. The search
order is specified at run-time rather than the time a new
vocabulary is created.
4 DISADVANTAGES
By migrating to a common structure, vendors give up one
point at which they may claim their product is better than
others. Another drawback is that the number of CONTEXT
vocabularies is fixed; older methods had an indefinite 'tree'
structure. In practice, the branching of such a structure was
very rarely greater than four.
Forth words operate in a context sensitive environment, as
word names may be redefined and have different definitions in
different vocabularies. This proposal compounds the problem. By
displaying the search order names, the user at least can readily
verify the search order.
5 IMPACT
The text of the Forth 83 Standard has been carefully chosen
for consistency and generality. However, no specification on how
the search order is developed by the user is given. This
omission is unavoidable, due to the diversity of contemporary
practice. This proposal is intended to complete the Forth 83
requirements in a fashion that exceeds all other methods.
Previously standardized words continue in their use:
VOCABULARY, FORTH, DEFINITIONS, and FORGET. However, this
proposal assumes that vocabulary names are not IMMEDIATE .
6 DEFINITIONS
Search order:
The sequence in which vocabularies are selected when
locating a word by name in the dictionary. Consists of one
transient and up to three resident vocabularies.
Transient order:
Execution of any vocabulary makes it the first vocabulary
searched, replacing the previously selected transient
vocabulary.
67
C. EXPERIMENTAL PROPOSALS
Resident order:
After searching the transient order, up to three additional
vocabularies may be searched. The application program
controls this selection.
7 GLOSSARY
ONLY -- ONLY
Select just the ONLY vocabulary as both the transient
vocabulary and resident vocabulary in the search order.
FORTH -- ONLY
The name of the primary vocabulary. Execution makes FORTH
the transient vocabulary, the first in the search order, and
thus replaces the previous transient vocabulary.
ALSO -- ONLY
The transient vocabulary becomes the first vocabulary in the
resident portion of the search order. Up to the last two
resident vocabularies will also be reserved, in order,
forming the resident search order.
ORDER -- ONLY
Display the vocabulary names forming the search order in
their present search order sequence. Then show the
vocabulary into which new definitions will be placed.
WORDS -- ONLY
Display the word names in the transient vocabulary, starting
with the most recent definition.
FORGET -- ONLY
Used in the form:
FORGET <name>
____
Delete from the dictionary <name> and all words added to the
____
dictionary after <name> regardless of the vocabulary.
____
Failure to find <name> is an error condition. An error
____
condition also exists upon implicitly forgetting a
vocabulary (due to its definition after <name>).
____
DEFINITIONS -- ONLY
Select the transient vocabulary as the current vocabulary
into which subsequent definitions will be added.
SEAL -- ONLY
Delete all occurances of ONLY from the search order. The
effect is that only specified application vocabularies will
be searched.
68
C. EXPERIMENTAL PROPOSALS
8 TYPICAL SOURCE CODE
0 ( ALSO ONLY 82jun12 WFR )
1 ( note the systems -FIND searches 1 to 5 vocabs in CONTEXT )
2 VOCABULARY ONLY ONLY DEFINITIONS
3 : ALSO ( slide transient into resident )
4 CONTEXT DUP 2+ 6 CMOVE> ;
5
6 HERE 2+ ] ( alter run time from usual vocabulary )
7 DOES> CONTEXT 8 ERASE DUP CONTEXT ! CONTEXT 8 + !
8 ALSO EXIT [
9 ' ONLY CFA ! ( Patch into ONLY; make NULL word )
10 CREATE X ' EXIT >BODY X ! 41088 ' X NFA ! IMMEDIATE
11 : FORTH FORTH ;
12 : DEFINITIONS DEFINITIONS ; : FORGET FORGET ;
13 : VOCABULARY VOCABULARY ; : ONLY ONLY ;
14 : WORDS WORDS ;
15
0 ( ORDER 82jun12 WFR )
1 : ORDER ( show the search order )
2 10 SPACES CONTEXT 10 OVER + SWAP
3 DO I @ ?DUP 0= ?LEAVE ID. 2 +LOOP
4 10 SPACES CURRENT @ ID. ;
5
6 ONLY FORTH ALSO DEFINITIONS
7
8
9
10
11
12
13
14
15
9 EXAMPLES OF USE
ONLY reduce search order to minimum
FORTH search FORTH then ONLY
ALSO EDITOR search EDITOR, FORTH then ONLY
DEFINITIONS new definitions will be added into the EDITOR
The same sequence would be compiled:
: SETUP ONLY FORTH ALSO EDITOR DEFINITIONS ;
10 REFERENCES
W. F. Ragsdale, The 'ONLY' Concept for Vocabularies, Proceedings
___________
of the 1982 FORML Conference, pub. Forth Interest Group.
____________________________
69
C. EXPERIMENTAL PROPOSALS
W. F. Ragsdale, fig-FORTH Installation Manual, Forth Interest
_____________________________
Group.
70
C. EXPERIMENTAL PROPOSALS
DEFINITION FIELD ADDRESS CONVERSION OPERATORS
by
Kim R. Harris
A. INTRODUCTION
The standard provides a transportable way to obtain the
compilation address of a definition in the dictionary of a FORTH
system (cf., FIND and ' ). It also provides an operator to
convert a compilation address to its corresponding parameter
field address. However, the standard does not provide a
transportable way to convert either of these addresses to the
other fields of a definition. Since various FORTH
implementations have different dictionary structures, a standard
set of conversion operators would increase transportability and
readability.
A set of words is proposed which allows the conversion of any
definitions field address to any other.
B. GLOSSARY
In the following words, the compilation address is either the
source or the destination, so it is not indicated in the names.
>BODY addr1 -- addr2 "to-body"
addr2 is the parameter field address corresponding to the
compilation address addr1.
>NAME addr1 -- addr2 "to-name"
addr2 is the name field address corresponding to the
compilation address addr1.
>LINK addr1 -- addr2 "to-link"
addr2 is the link field address corresponding to the
compilation address addr1.
BODY> addr1 -- addr2 "from-body"
addr2 is the compilation address corresponding to the
parameter field address addr1.
NAME> addr1 -- addr2 "from-name"
addr2 is the compilation address corresponding to the name
field address addr1.
71
C. EXPERIMENTAL PROPOSALS
LINK> addr1 -- addr2 "from-link"
addr2 is the compilation address corresponding to the link
field address addr1.
The previous set of words is complete, but may be inefficient for
going between two fields when one is not the compilation address.
For greater efficiency, additional operators may be defined which
name both the source and destination fields.
N>LINK addr1 -- addr2 "name-to-link"
addr2 is the link field address corresponding to the name
field address addr1.
L>NAME addr1 -- addr2 "link-to-name"
addr2 is the name field address corresponding to the link
field address addr1.
C. DISCUSSION
The previous words provide a complete, consistent, and efficient
set of definition field address conversion operations. They can
be implemented in a FORTH system which uses any combination of
the following options for its dictionary structure:
Link fields first or second.
Fixed or variable length name fields.
Additional fields in the definitions structure.
Heads contiguous or separated from bodies.
Indirect, direct, subroutine, or token threaded code.
The words are compatible with this standard; their inclusion
would not require other changes to be made to the standard.
Disadvantages to including them in the standard include:
They add 6 to 8 more words to the standard.
A standard program may not use all of them since it is not
allowed to access the name or link fields. However, this
does not disqualify them from being in the standard.
If a definition's head is not in the dictionary, an error
condition would exist. In this case, what action should the
words take in an implemented system?
The author of this experimental proposal recommends that FORTH
system implementors try them and that they be included in the
System Word Set of the next FORTH standard.
72
C. EXPERIMENTAL PROPOSALS
D. SOURCE CODE EXAMPLE
High level source code is shown below for a very simple
dictionary structure. This code assumes a FORTH system which
uses indirect threaded code, heads contiguous to bodies, and a
definition structure of the following format:
Name field, 4 bytes long, fixed length.
Link field, 2 bytes long.
Code field, 2 bytes long.
Parameter field, variable length.
: >BODY ( acf -- apf ) 2+ ;
: BODY> ( apf -- acf ) 2- ;
: >LINK ( acf -- alf ) 2- ;
: LINK> ( alf -- acf ) 2- ;
: >NAME ( acf -- anf ) 6 - ;
: NAME> ( anf -- alf ) 6 + ;
: N>LINK ( anf -- alf ) 4 + ;
: L>NAME ( alf -- anf ) 4 - ;
E. EXAMPLES OF USE
No examples are given because their use should be obvious.
73
D. CHARTER
APPENDIX D.
CHARTER
of the
FORTH STANDARDS TEAM
1. Purpose and Goals
1.1 Purpose
1.1.1 This Charter establishes and guides a voluntary
membership professional organization, the FORTH Standards
Team (hereafter referred to as the "FST") and provides a
method for its operation.
1.2 Goals
1.2.1 The goal of the FST is the creation, maintenance, and
proliferation of a standard (hereafter referred to as the
"Standard") for the FORTH computer programming system and
for application programs executed by a Standard system. The
Standard shall specify requirements and constraints which
such computer software must satisfy.
1.2.2 The team shall also develop a method of
identification and labeling of FORTH implementations and
programs which conform to the Standard.
1.3 Organization
1.3.1 The FST is a voluntary membership organization with
no formal status as a legal entity. It operates by
consensus of the professional and commercial FORTH community
and conducts business by the professional discourse and
agreement of its members. It is intended that this Charter
be a guide to the operation of the FST subject to reasonable
minor digression, rather than being a rigid document under
which vested rights are granted.
74
D. CHARTER
2. METHODS
2.1 Formal Meetings
2.1.1 The FST shall hold periodic formal meetings for
discussion and decisions concerning a current or future
Standard.
2.1.2 There is not specified frequency for formal meetings.
Each meeting shall be at such time and place as was decided
at the prior meeting. If a meeting cannot be held as
decided, the Chairperson may designate another time and
place.
2.1.3 The Chairperson shall send a written notice at least
sixty (60) days in advance of each formal meeting to each
voting member. A longer notification period is recommended.
It is anticipated that the continuing close coordination of
the participants, the decision at the prior formal meeting,
and publication of a meeting notice in FORTH Dimensions and
________________
other trade journals will provide sufficient notice to the
FORTH community.
2.1.4 At a formal FST meeting, there shall be general
sessions consisting of all attendees. General sessions are
for matters that are ready for discussion and decision. All
votes concerning the Standard, Charter, or FST procedures
must take place during a general session.
2.1.5 Also at formal meetings, subteams will be established
to examine groups of proposals and to prepare
recommendations for a general session. All meeting
attendees may participate in the work and voting of a
subteam. Each subteam should elect from its members a
coordinator to conduct its meetings and a reporter to record
and report its recommendations.
2.1.6 The Chairperson may publish and distribute an agenda
at or in advance of a formal meeting. As a guideline, each
day of a formal meeting begins with a general session,
followed by concurrent subteam meetings followed by another
general session.
2.1.7 In view of the voluntary nature of the FST, at least
one third of the membership is required to hold a formal
meeting. Two thirds of the number of voting members present
at the start of each day's first general session shall set
the quorum for the remainder of that day.
75
D. CHARTER
2.1.8 Between formal meetings, the Chairperson may appoint
such informal working groups as is appropriate. Each group
may be given a goal and scope to direct its activities. Its
conclusions or recommendations must be given to the
Chairperson in written form.
2.2 Proposals and Comments
2.2.1 Prior to each formal meeting, the Chairperson may
solicit submission of comments and proposals for changes,
additions, or deletions to the then-current Standard, the
draft Standard or this Charter. A cutoff date may be
specified for the submission of such proposals.
2.2.2 A considerable amount of information must accompany
each proposal to help FST members analyze the proposal.
Therefore, submission of proposals and comments shall be
according to the format and instructions shown in the
"Proposal/Comment Form" included as an Appendix to this
Standard. Any proposal not in the appropriate form or
received after the cutoff date may not be considered unless
the Chairperson deems it to be of sufficient significance.
2.2.3 Unsolicited proposals and comments by volunteers are
acknowledged as valuable. Any individual or group may
submit proposals and/or comments concerning the Standard or
this Charter. These should be sent to the official address
of the FST. Properly formatted proposals and comments are
preferred. The author or a representative should plan to
attend the next formal meeting to emphasize, support, and
possibly modify the proposals.
2.2.4 Since the quantity of proposals and comments may
exceed the number for which there is time to be voted upon,
submission of a proposal does not automatically mean that it
will be voted upon at the next formal FST meeting. The
Chairperson or some members appointed by the Chairperson or
elected by the voting members may screen and organize the
received proposals and comments for voting upon at the next
formal meeting.
2.2.5 To allow reflection and examination, proposals and
comments shall be distributed to FST voting members and
sponsors in advance of a formal meeting. Proposals and
comments not distributed in advance, including proposals
made during a formal meeting, may be considered at the
discretion of the Chairperson.
76
D. CHARTER
2.3 Draft Standard
After a formal meeting, the referees and officers of the FST
shall prepare a draft Standard for review by the then-
current FST voting members. The referees and officers shall
consolidate proposals accepted by vote during the meeting,
resolve any ambiguities or problems, and incorporate these
changes with the text of the previous Standard or draft
Standard.
2.4 Standard
2.4.1 The referees and officers may, by near unanimous
decision (not more than one no vote), declare the draft
Standard, as mentioned in the previous paragraph, as being
the proposed Standard.
2.4.2 A proposed Standard shall be distributed to all FST
voting members for a mail ballot. This ballot shall be
based solely on the text of the proposed Standard as
distributed.
2.4.3 Each ballot returned shall be signed by the voting
member submitting it. An affirmative vote of at least two
thirds of the voting members shall adopt the document. Such
adoption makes the draft Standard the current, official FST
Standard which supersedes all prior Standards.
2.5 Charter
2.5.1 At a formal FST meeting, the charter may be amended
by a simple majority of voting members present provided that
at least one third of all voting members are present; such
amendments become effective at the end of the current formal
meeting.
2.5.2 At other than a formal FST meeting, the charter may
be amended by a simple majority of all voting members, such
vote to be taken by signed mail ballots.
77
D. CHARTER
3. MEMBERSHIP
3.1 General
Membership in the FST is a privilege, not a right. An
invitation for voting membership may be extended to those
who the FST feels can contribute to the goals of the
Standard and the FST. There are several classes of
participation in the efforts of the FST. Membership in each
class has no specified term but continues from the time when
membership is initiated to the conclusion of the next formal
meeting.
3.2 Voting Members
3.2.1 Voting members are individuals who are elected into
such membership at the concluding session of a formal FST
meeting. Any voting member who resigns between formal
meetings shall not be replaced until the membership
elections at the conclusion of the next formal meeting. A
newly elected voting member gains voting rights only after
all voting members have been elected. A significant
professional FORTH background is required of voting members.
3.2.2 Each voting member present at a formal meeting shall
indicate in writing his or her desire to continue as a
voting member. Only these voting members can vote in a
general session of a formal meeting on any matters affecting
the Standard or the Charter and on the election of all
voting members.
3.2.3 Voting members are elected by a simple majority of
those voting members present. The number of voting members
shall be limited to thirty (30). Individuals eligible to be
elected are selected from each of the following ordered
categories in order, until the number of voting members
reaches the limit.
3.2.3.1 Category 1: current voting member who have
actively participated in at least two days of a formal
meeting. Voting members are expected to actively
participate in subteam meetings and all general
sessions.
3.2.3.2 Category 2: current voting members who are
not eligible by Category 1, but who have requested in
writing that his or her voting membership be
maintained.
3.2.3.3 Category 3: eligible candidates. Eligible
candidates will be presented to the voting members then
elected as follows:
78
D. CHARTER
3.2.3.3.1 If the number of eligible candidates
does not exceed the number of openings for voting
membership, each candidate is voted upon and
accepted by a simple majority.
3.2.3.3.2 If the number of eligible candidates
does exceed the number of openings for voting
membership, candidates will be voted upon by
ballot whereby each voting member may vote for up
to the number of openings remaining. Those
candidates receiving the most votes will be
elected until there are no more openings for
voting membership.
3.3 Candidates
3.3.1 Candidates are individuals who desire to actively
participate in and support the FST by becoming voting
members.
3.3.2 To be eligible, each Candidate must: declare in
writing to the secretary at the first general session of a
formal FST meeting that he or she is a Candidate, actively
participate in subteam meetings and all general sessions at
a formal FST meeting, and have a significant professional
background in FORTH. The Chairperson may request
information or ask questions of any candidate to determine
his or her technical knowledge and experience. Candidates
are expected to submit proposals, participate in the
discussions of the formal meeting, and contribute to the
work and voting of subteams.
3.4 Observers
3.4.1 Observers are individuals who attend a formal meeting
but are neither voting members nor candidates. At the
discretion of the Chairperson, they may contribute to the
discussion at general sessions and to the work of subteams.
The number of observers allowed at a formal meeting may be
limited by the Chairperson.
3.5 FST Sponsors
3.5.1 FST sponsors are individuals or organizations who
contribute funds and other assistance to aid the work of the
FST. FST sponsors have no duties or responsibilities in the
FST, but they will receive copies of proposals and comments
considered at a formal meeting, and drafts and adopted
standards prepared as a result of that meeting.
79
D. CHARTER
3.5.3 FST sponsorship exists from the end of one formal
meeting to the end of the next formal meeting.
3.5.3 Qualification of FST sponsors may be determined by a
simple majority vote at a formal FST meeting. If no such
qualification exist, the Chairperson may specify
qualifications, including the amount of financial
contributions, which will remain in effect until the next
formal FST meeting.
4. OFFICERS
4.1 General
There shall be four types of elected officers of the FST:
the Chairperson, the Secretary, the Treasurer, and one or
more Referees. Each officer shall be elected at a formal
meeting of the FST and serve until the next formal meeting.
4.2 Vacancies
If any office other than the Chairperson becomes vacant
between formal meetings, the Chairperson may appoint a
replacement. If the office of the Chairperson becomes
vacant between formal meetings, a new Chairperson shall be
elected by an informal majority vote of the remaining
officers. At any formal meeting, any officer, including the
Chairperson, may be replaced by a simple majority vote of
the voting members present at that meeting.
4.3 Chairperson
4.3.1 The Chairperson is responsible for governing the
general business of the FST. He or she is responsible for
implementing the FST's Charter and any other requirements
specified by the Standard.
4.3.2 The Chairperson's term of office shall be from the
conclusion of the formal meeting at which he or she is
elected to the conclusion of the next formal meeting. The
election of a Chairperson is held at the concluding general
session of a formal meeting after the election of voting
members; hence, newly elected voting members may vote for
the Chairperson. Only voting members are eligible to be
elected Chairperson.
4.3.3 The Chairperson shall conduct each formal meeting.
In general, the meetings will follow the current Robert's
________
Rules of Order; however, the Chairperson may determine the
______________
specific rules for a formal meeting.
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D. CHARTER
4.3.4 Any matter needing a decision between formal meetings
not specified by this Charter shall be decided by the
Chairperson.
4.3.5 The Chairperson has duties and responsibilities
specified elsewhere in this Charter.
4.4 Secretary
4.4.1 The Secretary is responsible for recording the
activities and results of the FST.
4.4.2 The Secretary is elected at the first general session
of a formal meeting and serves until a Secretary is elected
at the beginning of the next formal meeting.
4.4.3 The Secretary has many responsibilities.
4.4.3.1 The Secretary is responsible for collecting,
maintaining, and archiving the official copies of the
Standard, the Charter, all other FST documents,
correspondence, and lists of the FST members of each class.
4.4.3.2 During a formal meeting, the Secretary is
responsible for:
(a) Keeping the minutes of the general sessions,
including all votes taken. For votes affecting the
Standard or Charter, he or she shall: record the
number of voting members present, determine if a quorum
is present, determine the number of affirmative votes
required for the vote to pass, the number of voting
members voting in the affirmative and negative, and the
result of the vote.
(b) Recording and verifying the attendance and
membership class of each attendee.
(c) Recording the recommendations of subteams.
4.4.3.3 The Secretary is also responsible for collecting,
archiving, and distributing proposals before a formal
meeting. He or she is also responsible for incorporating
proposals accepted during a formal meeting into the Standard
or Charter. Other officers aid the Secretary in these
duties.
4.5 Treasurer
4.5.1 The Treasurer is responsible for managing the
financial business of the FST. He or she is responsible for
maintaining accurate and current financial records and for
accepting and dispersing funds for official FST activities.
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D. CHARTER
4.5.2 The Treasurer's term of office shall be from the
conclusion of the formal meeting at which he or she is
elected to the conclusion of the next formal meeting. The
election of a Treasurer is held just after the election of
the Chairperson. Only voting members are eligible to be
elected Treasurer.
4.6 Referees
4.6.1 At the conclusion of a formal meeting there may be
additional technical work required to prepare a draft
Standard or Charter. This work shall be performed by the
officers of the FST, including a group of Referees. They
should be individuals who have superior knowledge and
experience in the implementation and use of FORTH.
4.6.2 At least three and no more than five Referees shall
be elected by a majority of the voting members present at
the concluding general sessions of a formal meeting. This
takes place after the election of voting members. A
Referee's term is from election at the end of one formal
meeting until the end of the next formal meeting. Only
voting members are eligible to be elected as Referees.
4.6.3 The Referees shall adopt methods and rules as they
deem appropriate to complete their work; they may be
informal. However, any matter committed to the Referees for
resolution must achieve near unanimous agreement (not more
than one no vote). Lacking that, the matter shall be
omitted from further action pending further consideration at
the next formal meeting.
5. EXPERIMENTAL PROPOSALS
5.1 General
5.1.1 Since FORTH is an extensible language and subject to
evolution, the Standard may contain a section describing
experimental proposal to aid in the analysis of and the
decision for or against future adoption into the Standard.
After the results of experimentation are known, each
proposal will be considered, at a future formal meeting, for
inclusion into the Standard.
5.1.2 An experimental proposal may be individual FORTH
words, sets of related words, or specifications for part of
the Standard. Experimental proposals may be derived from
ordinary proposals or other contributions.
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D. CHARTER
5.2 Required Information
Each experimental proposal must contain the following
minimum information:
5.2.1 A description of the proposal including an overview
of its functions and its interactions with existing FORTH
words.
5.2.2 A glossary entry of each word in the form and
notation of the Standard.
5.2.3 A statement by the author(s) indicating why the
proposal meets inclusion into the Standard. Both advantages
and disadvantages should be discussed.
5.3 Suggested Information
It is suggested that each experimental proposal also
include:
5.3.1 A source definition for each word in the proposal.
High level definitions using Standard words are preferred,
but new primitive words may be defined in an assembly
language of one commonly-known processor. Sufficient
documentation should be provided so that implementation on
other processors is direct.
5.3.2 An example showing usage of the new words.
6. VOTING
6.1 General
Only voting members have the right to vote on proposals
affecting the Standard, a draft Standard, or this Charter.
6.2 Advisory Votes
At the discretion of the Chairperson, advisory votes may be
requested at a formal meeting. At the discretion of the
Chairperson, all attendees may participate in an advisory
vote.
6.3 Method
Any vote at a formal meeting may be by show of hands or, at
the discretion of the Chairperson, by an informal secret
paper ballot or a roll call.
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D. CHARTER
6.4 Number
A vote to adopt a proposal into the draft Standard or to
change the Standard, except for the Experimental Proposals
section of the Standard requires a two-thirds affirmative
vote of the voting members present at a general session of a
formal meeting, provided that the number of votes cast are
at least two thirds of that morning's quorum count. To
adopt an experimental proposal into the Experimental
Proposals section of the draft Standard or to change this
Charter, an affirmative vote of a simple majority is
required. Accepting any other procedural matter at a formal
meeting requires only a simple majority affirmative vote.
6.5 Proxies
All votes must be cast by the particular voting member
eligible to vote. No proxy voting is allowed.
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E. PROPOSAL/COMMENT FORM
APPENDIX E. PROPOSAL/COMMENT FORM
The following pages are the proposal and/or comment submittal
form. The form includes instructions which should be
explanatory. Copies of submitted proposals and comments will be
made available to FORTH Standards Team members and to team
sponsors.
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FST Proposal and Comment Submittal Form
-----------------------------------------------------------------
FST USER Title: Proposal Number:
ONLY --> Related Proposals: Disposition:
=================================================================
Keyword(s): Category:
( ) Proposal or ( ) Comment
FORTH Word(s): Section #(s):
-----------------------------------------------------------------
Abstract:
-----------------------------------------------------------------
Proposal and Discussion:
----------------------------------------------------------------
Submitted by: Date:
Page of
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FORTH Standards Team; PO Box 4545; Mountain View, CA 94040 820801
86
Proposal and Comment Submittal Form Instructions
Please use the supplied forms for your entire proposal. The
continuation form is only to be used if absolutely necessary; try
to get your proposal to fit on the first sheet. If it helps, use
a reducing copy machine to get more material onto the first
sheet. If you must use multiple sheets, put the main idea onto
the first sheet and less important material onto continuation
sheets. Remember that material on continuation sheets may be
overlooked.
The proposal forms have been produced on a computer system so
that you may produce your proposals using your own computer
system. If you print your proposal and form on your computer
system, all of the information shown on the form(s) MUST be
printed and in the same location.
The following are the instructions for each of the areas of the
form:
1. Please think of the most appropriate keyword or keywords
describing your proposal.
2. Select the best of the following categories of proposals:
0 Nucleus Layer other than #1 (i.e., + AND )
1 Memory Operations (i.e., @ CMOVE )
2 Dictionary (i.e., ' FORGET )
3 String Operations (i.e., WORD COUNT )
4 Interpreter Layer other than #2 or #3 (i.e., ABORT . )
5 Compiler Layer (i.e., : DO )
6 Device Layer (i.e., BLOCK TYPE )
7 Experimental (i.e., 32-bit stack entries)
8 Other Technical (i.e., mono-addressing)
9 Charter
3. Mark whether this is a PROPOSAL or a COMMENT.
4. Indicate which FORTH word or words are relevant.
5. Indicate which section or sections of the Standard are
relevant.
6. The abstract must be kept short. The title, keywords,
category, and abstract may be used in a database for
organization and display on a terminal during a Standards
Team meeting.
7. Detail your proposal and provide supporting discussion.
8. Indicate the name of the submitter or the names of the
submitters.
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9. Finally, date the submittal and number each page.
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FST Proposal and Comment Submittal Continuation Form
-----------------------------------------------------------------
FST USE ONLY --> Proposal Number:
=================================================================
-----------------------------------------------------------------
Submitted by: Date:
Page of
=================================================================
FORTH Standards Team; PO Box 4545; Mountain View, CA 94040 820801
89
https://forth.sourceforge.net/standard/fst83/
------------------------------------------------------------------------
All 132 FORTH83 words:
!