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Maclisp cross assembler for 6502.

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Courtesy of Leigh Klotz.
This commit is contained in:
Lars Brinkhoff
2021-04-28 08:31:44 +02:00
parent 1336be3042
commit 36339cdf15
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doc/klotz/assem.files Executable file
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Here is a list of all the files which make up the MacLisp Cross Assembler along
with a brief description of each.
KLOTZ; PASS1 >
The main body of the assembler. Conses up a big list of
the code, one line at a time. If there is no undefined reference on a a
line, it is completely assembled at read-time. Otherwise, a notation is made of
undefined references. Later, when these references are resolved the code
with the undefined reference is completed.
KLOTZ; TOKENZ >
The Tokenizer. The routines for reading in tokens and strings.
KLOTZ; ARMACS >
Code for defining assembler read macros.
Definitions of assembler read macros.
KLOTZ; DEFDEF >
The code for DEFINS (define instruction), DEFAMODE (define addessing
mode), and DEF-PSEUDO-OP.
APLOGO;EVAL >
The routines for evaluating symbols and arithmatic expressions.
APLOGO;MATCH >
Winning simple pattern matcher for parsing losing assembler expressions.
Used by DEFINS and PASS1 for determining addressing mode.
KLOTZ; 6502 >
These are the definitions for the 6502 addressing modes and instructions.
KLOTZ;DECPOP >
These are the assembler DEC compatability pseudo-op directives.
KLOTZ;PASS1 IDEAS
Old documentation for how pass1 ought to work. Somewhat obsolete, but nonetheless
informative.
KLOTZ;POPDEC DOC
Documentation for the assembler DEC compatability pseudo-op directives.
KLOTZ;ASSEM FILES
?

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doc/klotz/assem.ideas Executable file
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This is my attempt at one-pass assembly.
First get a token. If it has a PREFIX-OP (opcode or pseudo-op) property
then hand control to the function in that property. Do not try to
collect arguments for it, since it might want string arguments (e.g.
".TITLE APPLE-LOGO"). If it wants tokens, it will call gettok itself.
If the first token on the line is has no PREFIX-OP property then it
still might be an infix-style assignment statement (i.e. "=", or ":").
So we save the old token, get another token, and check to see if
that token has a INFIX-OP property. If so, then it is called and given
as an argument the first token on the line. This type of PSEUDO-OP would
also call gettok or whatever it feels like calling and finally return.
All of the functions described above should return whatever they want
put in the list as code. Of course, they may have appropriate side
efects.
If any token is undefined, whatever worries about it should look on the
FORWARD-REF property of the token (This is a job for ASSEM-SYMEVAL for
symbols and ASSEMBLE-CODE for operators.) and put a FORWARD-REF property
on them. The forward ref property (which should be a list of the new
and all the old FORWARD-REF properties still unresolved) should contain
a pointer to the place where the code for this instruction will be
pushed onto the list of all code (The first element of the
whole-code-list when the reference was made.) as the cdr of the
succesive cadr's of the FORWARD-REF property and the name of the
undefined reference as the car of the cadr's. Totally unclear?
;;;;; Stuff below has note been correced. Error checking, etc. (LDA
FOO), then FOO=> $2345. Either an error or (LDA 69.). Either way, it
requires some checking. Maybe we shouldn't partially assemble the
instruction when there is an undefined reference in it, and let the
undef-ref handler do it. It wouldn't be difficult at all; just let IT
call the various propertys of the symbol.) The undef-ref handler just
rplacd's the undefined reference (although it might be an expression. We
should do an NSUBLIS (Which is like SUBLIS except it bashes its argument
and isn't written. We'd have to write it. Big deal.). This
automatically changes the reference. It should also remove the pointer
from the FORWARD-REF property of the token and place the new value on
the LABEL-VALUE property. When theassembleris through, we do a MAPTAOMS
looking for FORWARD-REF (perhaps we should call it UNDEF-REF) and
LABEL-VALUE properties and print out our symbol table from there.

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doc/klotz/dec.pseudo Executable file
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MacLisp Cross Assembler Documentation. KLOTZ.
DEC compatability pseudo-op stuff.
; Begins comment field
' Indicates single ASCII character as a term in expressions.
^O Indicates octal number
^B Indicates binary number
= Symbol assignment
. Current location counter
$ Indicates hexadecimal number
Default radix is decimal.
.ADDR Generates a 16-bit address with the bytes in the proper order,
i.e., <low> <high>.[TO DO]
.ASCII ASCII string delimited by paired markers.
.ASCIZ ASCIZ string delimited by paired markers and supplied with
terminal null byte.
.BLKBA Allocate space for a number of bytes as specified by the operand.
.BLKW Allocate space for a number of words as specified by the operand.
.BYTE Each expression supplied will be stored in a single byte.[In
progress. Eval-Expression does what with commas, and best way to cons it
up.]
.END End of program.
.ISET Specifies the instruction set to be used, "6502" or "TI990".
.PAGE Force a page break. Does nothing useful now.
.PRINT Print the text which follows on the terminal.
.RADIX Change the radix to the value specified to this directive.
.SBTTL Specify subtitle text. Prints out TOC on screen if
SILENT-RUNNING isn't specified (via the /N switch.)
.TITLE Specify title text.
.WORD Allocate space for each value specified. [Same as .BYTE for 8 bit machines.]
-------------------------
Things for the Future:
.REPT (.REPT <n>) Repeat the body of this directive the indicated
number of times.
.NTYPE sym,arg The symbol is equated to the addressing mode of the argument.
.NCHR sym,<str> The symbol is equated to the number of characters in <str>
.NARG sym The symbol is equated to the number of arguments to the macro
.MEXIT Leave macro expansion
Begin a macro definition
.MCALL Call macros from the system library.
.IRPC sym,<str>Indefinite repeat of body based upon number of characters in
<str>.
.MACRO name <arglist>Immediate if; if condition is met, stmnt is emitted.
.IRP sym,<arglist> Indefinite repeat of body based upon number of parameters in
<arglist>..IIF condition, arg, stmnt
.IF Enter a conditional.
.IFDF .IFDF <symbol> true if symbol is defined. See also .IFNDF.
.IFEQ .IFEQ <expression> true if expression evaluates to zero.
.IFF Begins body of conditional if enclosing condition was false.
.IFG .IFG <expression> true if expression greater than zero.
.IFGE .IFG <expression> true if expression greater than or equal to
zero.
.IFGT Same as .IFG
.IFL .IFL <expression> true if expression is negative.
.IFLE .IFLE <expression> true if expression is negative or zero.
.IFLT Same as .IFL.
.IFNDF .IFNDF <symbol> true if symbol is undefined.
.IFNE .IFNE <expression> true if expression is non-zero.
.IFNZ Same as .IFNE
.IFT Begins body of conditional if enclosing condition was true.
.IFZ Same as .IFE
.IIF condition, arg, stmnt
Immediate if; if condition is met, stmnt is emitted.
.IRP sym,<arglist> Indefinite repeat of body based upon number of parameters in
<arglist>.
[Nui mahope.]
.IRPC sym,<str>Indefinite repeat of body based upon number of characters in
<str>.
.MACRO name <arglist>
Begin a macro definition
.MEXIT Leave macro expansion
.NARG sym The symbol is equated to the number of arguments to the macro
.NCHR sym,<str> The symbol is equated to the number of characters in <str>
.NTYPE sym,arg The symbol is equated to the addressing mode of the argument.
--------------------
Assembler syntax quick summary
<...> Encloses any expression (the assembler's equivalent of
parentheses). Expressions are evaluated left-to-right without
operator heirarchy.
+ Addition or unary plus
- Subtraction or unary minus
* Multiplication
/ Division