13 *NOTE: Every effort has been made to ensure the accuracy and robustness of this
14 manual and the associated software. However, because Reboot is constantly improving
15 and updating its computer software, it is unable to guarantee
16 the accuracy of printed or duplicated material after the date of publication and
17 disclaims liability for changes, errors or omissions.*
20 *Copyright © 2011-2020, Reboot*
22 *All rights reserved.*
24 *Reboot Document number F00000K-001 Rev. A.*
36 This document describes RMAC, a fast macro assembler for the 68000. RMAC currently
37 runs on the any POSIX compatible platform and the Atari ST. It was initially written
38 at Atari Corporation by programmers who needed a high performance assembler
39 for their work. Then, more than 20 years later, because there was still a need for
40 such an assembler and what was available wasn't up to expectations, Subqmod
41 and eventually Reboot continued work on the freely released source, adding Jaguar
42 extensions and fixing bugs. Over time the assembler has been extended by adding
43 support for Motorola's 68020/30/40/60, 68881/2, DSP56001 CPUs as well as Atari's
44 Object Processor (OP) found on the Atari Jaguar.
46 RMAC is intended to be used by programmers who write mostly in assembly language.
47 It was not originally a back-end to a C compiler, therefore it
48 has creature comfort that are usually neglected in such back-end assemblers. It
49 supports include files, macros, symbols with limited scope, some limited control
50 structures, and other features. RMAC is also blindingly fast, another feature
51 often sadly and obviously missing in today's assemblers.\ [1]_
53 RMAC is not entirely compatible with the AS68 assembler provided with
54 the original Atari ST Developer's Kit, but most changes are minor and a few minutes
55 with an editor should allow you to assemble your current source files. If you are an
56 AS68 user, before you leap into the unknown please read the section on Notes for
59 .. [1] It processes 30,000 lines a minute on a lightly loaded VAX 11/780; maybe 40,000 on a 520-ST with an SH-204 hard disk. Yet it could be sped up even more with some effort and without resorting to assembly language; C doesn't have to be slow!
65 * The distribution disk contains a file called README that you should read.
66 This file contains important nays about the contents of the distribution disk
67 and summarizes the most recent changes to the tools.
69 * Hard disk users can simply copy the executable files to their work or binary
70 directories. People with floppy disks can copy the executables to ramdisks,
71 install the assembler with the -q option, or even work right off of the floppies.
73 * You will need an editor that can produce "normal" format text files. Micro
74 Emacs will work well, as will most other commercial program editors, but not
75 most word processors (such as First Word or Microsoft Write).
77 * You will probably want to examine or get a listing of the file "ATARI.S". It
78 contains lots of definitions for the Atari ST, including BIOS variables, most
79 BIOS, XBIOS and GEMDOS traps, and line-A equates. We (or you) could
80 split the file up into pieces (a file for line-A equates, a file for hardware and
81 BIOS variables and so on), but RMAC is so fast that it doesn't matter
84 * Read the rest of the manual, especially the first two chapters on The Command Line and Using RMAC.
85 Also, `Notes for migrating from other 68000 assemblers`_ will save a lot of time and frustration in the long run.
86 The distribution disk contains example
87 programs that you can look at, assemble and modify.
92 The assembler is called "**rmac**" or "**rmac.prg**". The command line takes the form:
94 **rmac** [*switches*] [*files* ...]
96 A command line consists of any number of switches followed by the names of files
97 to assemble. A switch is specified with a dash (**-**) followed immediately by a key
98 character. Key characters are not case-sensitive, so "**-d**" is the same as "**-D**". Some
99 switches accept (or require) arguments to immediately follow the key character,
100 with no spaces in between.
102 Switch order is important. Command lines are processed from left to right in
103 one pass, and switches usually take effect when they are encountered. In general it
104 is best to specify all switches before the names of any input files.
106 If the command line is entirely empty then RMAC prints a copyright message
107 along with usage info and exit.
109 Input files are assumed to have the extension "**.s**"; if a filename has no extension
110 (i.e. no dot) then "**.s**" will be appended to it. More than one source filename may be
111 specified: the files are assembled into one object file, as if they were concatenated.
113 RMAC normally produces object code in "**file.o**" if "**file.s**" is the first
114 input filename. If the first input file is a special character device, the output name
115 is noname.o. The **-o** switch (see below) can be used change the output file name.
118 =================== ===========
120 =================== ===========
121 -dname\ *[=value]* Define symbol, with optional value.
122 -e\ *[file[.err]]* Direct error messages to the specified file.
123 -fa ALCYON output object file format (implied when **-ps** is enabled).
124 -fb BSD COFF output object file format.
125 -fe ELF output object file format.
126 -fr Absolute address. Source code is required to have one .org statement.
127 -fx Atari 800 com/exe/xex output object file format.
128 -i\ *path* Set include-file directory search path.
129 -l\ *[file[prn]]* Construct and direct assembly listing to the specified file.
130 -l\ *\*[filename]* Create an output listing file without pagination.
131 -m\ *cpu* Switch CPU type
151 `tom - Jaguar GPU JRISC`
153 `jerry - Jaguar DSP JRISC`
155 -o\ *file[.o]* Direct object code output to the specified file.
156 +/~oall Turn all optimisations on/off
157 +o\ *0-30*/*p* Enable specific optimisation
158 ~o\ *0-30*/*p* Disable specific optimisation
160 `0: Absolute long adddresses to word (on by default)`
162 `1: move.l #x,Dn/An to moveq (on by default)`
164 `2: Word branches to short (on by default)`
166 `3: Outer displacement 0(An) to (An)`
170 `5: 68020+ Absolute long base/outer displacement to word`
172 `6: Convert null short branches to NOP`
174 `7: Convert clr.l Dn to moveq #0,Dn`
176 `8: Convert adda.w/l #x,Dy to addq.w/l #x,Dy`
178 `9: Convert adda.w/l #x,Dy to lea x(Dy),Dy`
180 `10: 56001 Use short format for immediate values if possible`
182 `11: 56001 Auto convert short addressing mode to long (default: on)`
184 `o30: Enforce PC relative (alternative name: op)`
186 -p Produce an executable (**.prg**) output file.
187 -ps Produce an executable (**.prg**) output file with symbols.
188 -px Produce an executable (**.prg**) output file with extended symbols.
189 -q Make RMAC resident in memory (Atari ST only).
190 -r *size* automatically pad the size of each
191 segment in the output file until the size is an integral multiple of the
192 specified boundary. Size is a letter that specifies the desired boundary.
194 `-rw Word (2 bytes, default alignment)`
198 `-rp Phrase (8 bytes)`
200 `-rd Double Phrase (16 bytes)`
202 `-rq Quad Phrase (32 bytes)`
203 -s Warn about unoptimized long branches and applied optimisations.
204 -u Force referenced and undefined symbols global.
205 -v Verbose mode (print running dialogue).
206 -x Turn on debugging mode.
207 -yn Set listing page size to n lines.
208 -4 Use C style operator precedence.
209 file\ *[s]* Assemble the specified file.
210 =================== ===========
212 The switches are described below. A summary of all the switches is given in
216 The **-d** switch permits symbols to be defined on the command line. The name
217 of the symbol to be defined immediately follows the switch (no spaces). The
218 symbol name may optionally be followed by an equals sign (=) and a decimal
219 number. If no value is specified the symbol's value is zero. The symbol at-
220 tributes are "defined, not referenced, and absolute". This switch is most useful
221 for enabling conditionally-assembled debugging code on the command line; for
226 -dDEBUG -dLoopCount=999 -dDebugLevel=55
229 The -e switch causes RMAC to send error messages to a file, instead of the
230 console. If a filename immediately follows the switch character, error messages
231 are written to the specified file. If no filename is specified, a file is created with
232 the default extension "**.err**" and with the root name taken from the first input
233 file name (e.g. error messages are written to "**file.err**" if "**file**" or "**file.s**" is
234 the first input file name). If no errors are encountered, then no error listing
235 file is created. Beware! If an assembly produces no errors, any error file from
236 a previous assembly is not removed.
239 The **-i** switch allows automatic directory searching for include files. A list of
240 semi-colon seperated directory search paths may be mentioned immediately
241 following the switch (with no spaces anywhere). For example:
245 -im:;c:include;c:include\sys
247 will cause the assembler to search the current directory of device **M**, and the
248 directories include and include\sys on drive **C**. If *-i* is not specified, and the
249 enviroment variable "**RMACPATH**" exists, its value is used in the same manner.
250 For example, users of the Mark Williams shell could put the following line in
251 their profile script to achieve the same result as the **-i** example above:
255 setenv RMACPATH="m:;c:include;c:include\sys"
257 The -l switch causes RMAC to generate an assembly listing file. If a file-
258 name immediately follows the switch character, the listing is written to the
259 specified file. If no filename is specified, then a listing file is created with the
260 default extension "**.prn**" and with the root name taken from the first input file
261 name (e.g. the listing is written to "**file.prn**" if "**file**" or "**file.s**" is the first
264 The -o switch causes RMAC to write object code on the specified file. No
265 default extension is applied to the filename. For historical reasons the filename
266 can also be seperated from the switch with a space (e.g. "**-o file**").
271 The **-p** and **-ps** switches cause RMAC to produce an Atari ST executable
272 file with the default extension of "**.prg**". If there are any external references
273 at the end of the assembly, an error message is emitted and no executable file
274 is generated. The **-p** switch does not write symbols to the executable file. The
275 **-ps** switch includes symbols (Alcyon format) in the executable file.
277 The **-q** switch is aimed primarily at users of floppy-disk-only systems. It causes
278 RMAC to install itself in memory, like a RAMdisk. Then the program
279 **m.prg** (which is very short - less than a sector) can be used instead of
280 **mac.prg**, which can take ten or twelve seconds to load. (**NOTE** not available
281 for now, might be re-implemented in the future).
283 The **-s** switch causes RMAC to generate a list of unoptimized forward
284 branches as warning messages. This is used to point out branches that could
285 have been short (e.g. "bra" could be "bra.s").
287 The **-u** switch takes effect at the end of the assembly. It forces all referenced
288 and undefined symbols to be global, exactly as if they had been made global
289 with a **.extern** or **.globl** directive. This can be used if you have a lot of
290 external symbols, and you don't feel like declaring them all external.
292 The **-v** switch turns on a "verbose" mode in which RMAC prints out (for
293 example) the names of the files it is currently processing. Verbose mode is
294 automatically entered when RMAC prompts for input with a star.
296 The **-y** switch, followed immediately by a decimal number (with no intervening
297 space), sets the number of lines in a page. RMAC will produce *N* lines
298 before emitting a form-feed. If *N* is missing or less than 10 an error message is
301 Use C style order of precedence in expressions. See `Order of Evaluation`_ for more
307 Let's assemble and link some example programs. These programs are included
308 on the distribution disk in the "**EXAMPLES**" directory - you should copy them to
309 your work area before continuing. In the following examples we adopt the conven-
310 tions that the shell prompt is a percent sign (%) and that your input (the stuff you
311 type) is presented in **bold face**.
313 If you have been reading carefully, you know that RMAC can generate
314 an executable file without linking. This is useful for making small, stand alone
315 programs that don't require externals or library routines. For example, the following
323 could be replaced by the single command:
329 since you don't need the linker for stand-alone object files.
331 Successive source files named in the command line are are concatenated, as in
332 this example, which assembles three files into a single executable, as if they were
337 % rmac -p bugs shift images
339 Of course you can get the same effect by using the **.include** directive, but sometimes
340 it is convenient to do the concatenation from the command line.
342 Here we have an unbelievably complex command line:
346 % rmac -lzorf -y95 -o tmp -ehack -Ddebug=123 -ps example
348 This produces a listing on the file called "**zorf.prn**" with 95 lines per page, writes
349 the executable code (with symbols) to a file called "**tmp.prg**", writes an error listing
350 to the file "**hack.err**", specifies an include-file path that includes the current
351 directory on the drive "**M:**," defines the symbol "**debug**" to have the value 123, and
352 assembles the file "**example.s**". (Take a deep breath - you got all that?)
354 One last thing. If there are any assembly errors, RMAC will terminate
355 with an exit code of 1. If the assembly succeeds (no errors, although there may be
356 warnings) the exit code will be 0. This is primarily for use with "make" utilities.
358 Things You Should Be Aware Of
359 '''''''''''''''''''''''''''''
360 RMAC is a one pass assembler. This means that it gets all of its work done by
361 reading each source file exactly once and then "back-patching" to fix up forward
362 references. This one-pass nature is usually transparent to the programmer, with
363 the following important exceptions:
365 * In listings, the object code for forward references is not shown. Instead, lower-
366 case "xx"s are displayed for each undefined byte, as in the following example:
370 60xx 1: bra.s.2 ;forward branch
371 xxxxxxxx dc.l .2 ;forward reference
372 60FE .2: bra.s.2 ;backward reference
374 * Forward branches (including **BSR**\s) are never optimized to their short forms.
375 To get a short forward branch it is necessary to explicitly use the ".s" suffix in
377 * Error messages may appear at the end of the assembly, referring to earlier source
378 lines that contained undefined symbols.
379 * All object code generated must fit in memory. Running out of memory is a
380 fatal error that you must deal with by splitting up your source files, re-sizing
381 or eliminating memory-using programs such as ramdisks and desk accessories,
386 RMAC does not optimize forward branches for you, but it will tell you about
387 them if you use the -s (short branch) option:
392 "example.s", line 20: warning: unoptimized short branch
394 With the -e option you can redirect the error output to a file, and determine by
395 hand (or editor macros) which forward branches are safe to explicitly declare short.
397 `Notes for migrating from other 68000 assemblers`_
398 ''''''''''''''''''''''''''''''''''''''''''''''''''
399 RMAC is not entirely compatible with the other popular assemblers
400 like Devpac or vasm. This section
401 outlines the major differences. In practice, we have found that very few changes are
402 necessary to make other assemblers' source code assemble.
404 * A semicolon (;) must be used to introduce a comment,
405 except that a star (*)
406 may be used in the first column. AS68 treated anything following the operand
407 field, preceeded by whitespace, as a comment. (RMAC treats a star that
408 is not in column 1 as a multiplication operator).
409 * Labels require colons (even labels that begin in column 1).
411 * Conditional assembly directives are called **if**, **else** and **endif**.
412 Devpac and vasm call these
413 **ifne**, **ifeq** (etc.), and **endc**.
414 * The tilde (~) character is an operator, and back-quote (`) is an illegal character.
415 AS68 permitted the tilde and back-quote characters in symbols.
416 * There are no equivalents to org or section directives apart from .text, .data, .bss.
417 The **.xdef** and **.xref** directives are not implemented,
418 but **.globl** makes these unnecessary anyway.
420 * The location counter cannot be manipulated with a statement of the form:
426 Exceptions to this rule are when outputting a binary using the **-fr** switch,
427 6502 mode, and Jaguar GPU/DSP.
428 * Back-slashes in strings are "electric" characters that are used to escape C-like
429 character codes. Watch out for GEMDOS path names in ASCII constants -
430 you will have to convert them to double-backslashes.
431 * Expression evaluation is done left-to-right without operator precedence. Use parentheses to
432 force the expression evaluation as you wish. Alternatively, use the **-4** switch to switch
433 to C style precedence. For more information refer to `Order of Evaluation`_.
434 * Mark your segments across files.
435 Branching to a code segment that could be identified as BSS will cause a "Error: cannot initialize non-storage (BSS) section"
436 * In 68020+ mode **Zan** and **Zri** (register suppression) is not supported.
437 * rs.b/rs.w/rs.l/rscount/rsreset can be simulated in rmac using **.abs**.
438 For example the following source:
448 size_so_far equ rscount
460 size_so_far equ ^^abscount
461 * A rare case: if your macro contains something like:
471 then by the assembler's design this will fail as the parameters are automatically converted to hex. Changing the code like this works:
483 For those using editors other than the "Emacs" style ones (Micro-Emacs, Mince,
484 etc.) this section documents the source file format that RMAC expects.
486 * Files must contain characters with ASCII values less than 128; it is not per-
487 missable to have characters with their high bits set unless those characters are
488 contained in strings (i.e. between single or double quotes) or in comments.
490 * Lines of text are terminated with carriage-return/line-feed, linefeed alone, or
491 carriage-return alone.
493 * The file is assumed to end with the last terminated line. If there is text beyond
494 the last line terminator (e.g. control-Z) it is ignored.
501 A statement may contain up to four fields which are identified by order of ap-
502 pearance and terminating characters. The general form of an assembler statement
507 label: operator operand(s) ; comment
509 The label and comment fields are optional. An operand field may not appear
510 without an operator field. Operands are seperated with commas. Blank lines are
511 legal. If the first character on a line is an asterisk (*) or semicolon (;) then the
512 entire line is a comment. A semicolon anywhere on the line (except in a string)
513 begins a comment field which extends to the end of the line.
515 The label, if it appears, must be terminated with a single or double colon. If
516 it is terminated with a double colon it is automatically declared global. It is illegal
517 to declare a confined symbol global (see: `Symbols and Scope`_).
519 As an addition, the exclamation mark character (**!**) can be placed at the very first
520 character of a line to disbale all optimisations for that specific line, i.e.
524 !label: operator operand(s) ; comment
528 A statement may also take one of these special forms:
530 *symbol* **equ** *expression*
532 *symbol* **=** *expression*
534 *symbol* **==** *expression*
536 *symbol* **set** *expression*
538 *symbol* **reg** *register list*
540 The first two forms are identical; they equate the symbol to the value of an
541 expression, which must be defined (no forward references). The third form, double-
542 equals (==), is just like an equate except that it also makes the symbol global. (As
543 with labels, it is illegal to make a confined equate global.) The fourth form allows
544 a symbol to be set to a value any number of times, like a variable. The last form
545 equates the symbol to a 16-bit register mask specified by a register list. It is possible
546 to equate confined symbols (see: `Symbols and Scope`_). For example:
550 cr equ 13 carriage-return
552 DEBUG == 1 global debug flag
554 count set count + 1 increment variable
555 .rags reg d3-d7/a3-a6 register list
556 .cr 13 confined equate
560 Symbols may start with an uppercase or lowercase letter (A-Z a-z), an underscore
561 (**_**), a question mark (**?**) or a period (**.**). Each remaining character may be an
562 upper or lowercase letter, a digit (**0-9**), an underscore, a dollar sign (**$**), or a question
563 mark. (Periods can only begin a symbol, they cannot appear as a symbol
564 continuation character). Symbols are terminated with a character that is not a
565 symbol continuation character (e.g. a period or comma, whitespace, etc.). Case is
566 significant for user-defined symbols, but not for 68000 mnemonics, assembler direc-
567 tives and register names. Symbols are limited to 100 characters. When symbols
568 are written to the object file they are silently truncated to eight (or sixteen) char-
569 acters (depending on the object file format) with no check for (or warnings about)
572 For example, all of the following symbols are legal and unique:
576 reallyLongSymbolName .reallyLongConfinedSymbolName
577 a10 ret move dc frog aa6 a9 ????
578 .a1 .ret .move .dc .frog .a9 .9 ????
579 .0 .00 .000 .1 .11. .111 . ._
580 _frog ?zippo? sys$syetem atari Atari ATARI aTaRi
582 while all of the following symbols are illegal:
586 12days dc.10 dc.z 'quote .right.here
587 @work hi.there $money$ ~tilde
590 Symbols beginning with a period (**.**) are *confined*; their scope is between two
591 normal (unconfined) labels. Confined symbols may be labels or equates. It is illegal
592 to make a confined symbol global (with the ".globl" directive, a double colon, or a
593 double equals). Only unconfined labels delimit a confined symbol's scope; equates
594 (of any kind) do not count. For example, all symbols are unique and have unique
595 values in the following:
606 .loop: move.w -1,(a0)+
610 Confined symbols are useful since the programmer has to be much less inventive
611 about finding small, unique names that also have meaning.
613 It is legal to define symbols that have the same names as processor mnemonics
614 (such as "**move**" or "**rts**") or assembler directives (such as "**.even**"). Indeed, one
615 should be careful to avoid typographical errors, such as this classic (in 6502 mode):
623 which equates a confined symbol to a hexadecimal value, rather than setting the
624 location counter, which the .org directive does (without the equals sign).
628 The following names, in all combinations of uppercase and lowercase, are keywords
629 and may not be used as symbols (e.g. labels, equates, or the names of macros):
637 d0 d1 d2 d3 d4 d5 d6 d7
638 a0 a1 a2 a3 a4 a5 a6 a7
640 r0 r1 r2 r3 r4 r5 r6 r7
641 r8 r9 r10 r11 r12 rl3 r14 r15
645 x x0 x1 x2 y y0 y1 y2
646 a a0 a1 a2 b b0 b1 b2 ab ba
647 mr omr la lc ssh ssl ss
648 n0 n1 n2 n3 n4 n5 n6 n7
649 m0 m1 m2 m3 m4 m5 m6 m7
650 r0 r1 r2 r3 r4 r5 r6 r7
655 Numbers may be decimal, hexadecimal, octal, binary or concatenated ASCII. The
656 default radix is decimal, and it may not be changed. Decimal numbers are specified
657 with a string of digits (**0-9**). Hexadecimal numbers are specified with a leading
658 dollar sign (**$**) followed by a string of digits and uppercase or lowercase letters (**A-F
659 a-f**). Octal numbers are specified with a leading at-sign (**@**) followed by a string
660 of octal digits (**0-7**). Binary numbers are specified with a leading percent sign
661 (**%**) followed by a string of binary digits (**0-1**). Concatenated ASCII constants are
662 specified by enclosing from one to four characters in single or double quotes. For
674 Negative numbers Are specified with a unary minus (**-**). For example:
683 Strings are contained between double (") or single ( ') quote marks. Strings may
684 contain non-printable characters by specifying "backslash" escapes, similar to the
685 ones used in the C programming language. RMAC will generate a warning if a
686 backslash is followed by a character not appearing below:
691 \n $0a line-feed (newline)
694 \r $0c1 carriage-return
700 It is possible for strings (but not symbols) to contain characters with their high
701 bits set (i.e. character codes 128...255).
703 You should be aware that backslash characters are popular in GEMDOS path
704 names, and that you may have to escape backslash characters in your existing source
705 code. For example, to get the file "'c:\\auto\\ahdi.s'" you would specify the string
706 "`c:\\\\auto\\\\ahdi.s`".
710 Register lists are special forms used with the **movem** mnemonic and the **.reg**
711 directive. They are 16-bit values, with bits 0 through 15 corresponding to registers
712 **D0** through **A7**. A register list consists of a series of register names or register
713 ranges seperated by slashes. A register range consists of two register names, Rm
714 and Rn,m<n, seperated by a dash. For example:
722 d0/d1/a0-a3/d7/a6-a7 $CF83
726 Register lists and register equates may be used in conjunction with the movem
727 mnemonic, as in this example:
731 temps reg d0-d2/a0-a2 ; temp registers
732 keeps reg d3-d7/d3-a6 ; registers to preserve
733 allregs reg d0-d7/a0-a7 ; all registers
734 movem.l #temps,-(sp) ; these two lines ...
735 movem.l d0-d2/a0-a2,-(sp) ; are identical
736 movem.l #keeps,-(sp) ; save "keep" registers
737 movem.l (sp)+,#keeps ; restore "keep" registers
742 `Order of Evaluation`_
743 ''''''''''''''''''''''
744 All values are computed with 32-bit 2's complement arithmetic. For boolean operations
745 (such as if or **assert**) zero is considered false, and non-zero is considered
748 **Expressions are evaluated strictly left-to-right, with no
749 regard for operator precedence.**
751 Thus the expression "1+2*3" evaluates to 9, not 7. However, precedence may be
752 forced with parenthesis (**()**) or square-brackets (**[]**).
754 All the above behavior is the default. However if the command line switch **-4**
755 is used, then C style of operator precedence is enforced. The following list
756 shows the order of precedence in this mode, from lowest to highest:
764 * relational = < <= >= > !=
774 Expressions belong to one of three classes: undefined, absolute or relocatable. An
775 expression is undefined if it involves an undefined symbol (e.g. an undeclared sym-
776 bol, or a forward reference). An expression is absolute if its value will not change
777 when the program is relocated (for instance, the number 0, all labels declared in
778 an abs section, and all Atari ST hardware register locations are absolute values).
779 An expression is relocatable if it involves exactly one symbol that is contained in a
780 text, data or BSS section.
782 Only absolute values may be used with operators other than addition (+) or
783 subtraction (-). It is illegal, for instance, to multiply or divide by a relocatable or
784 undefined value. Subtracting a relocatable value from another relocatable value in
785 the same section results in an absolute value (the distance between them, positive
786 or negative). Adding (or subtracting) an absolute value to or from a relocatable
787 value yeilds a relocatable value (an offset from the relocatable address).
789 It is important to realize that relocatable values belong to the sections they
790 are defined in (e.g. text, data or BSS), and it is not permissible to mix and match
791 sections. For example, in this code:
795 linel: dc.l line2, line1+8
796 line2: dc.l line1, line2-8
797 line3: dc.l line2-line1, 8
798 error: dc.l line1+line2, line2 >> 1, line3/4
800 Line 1 deposits two longwords that point to line 2. Line 2 deposits two longwords
801 that point to line 1. Line 3 deposits two longwords that have the absolute value
802 eight. The fourth line will result in an assembly error, since the expressions (re-
803 spectively) attempt to add two relocatable values, shift a relocatable value right by
804 one, and divide a relocatable value by four.
806 The pseudo-symbol "*****" (star) has the value that the current section's location
807 counter had at the beginning of the current source line. For example, these two
808 statements deposit three pointers to the label "**bar**":
815 Similarly, the pseudo-symbol "**$**" has the value that the current section's location
816 counter has, and it is kept up to date as the assembler deposits information
817 "across" a line of source code. For example, these two statements deposit four
818 pointers to the label "zip":
828 ================================ ==========================================
830 ================================ ==========================================
831 **-** Unary minus (2's complement).
832 **!** Logical (boolean) NOT.
833 **~** Tilde: bitwise not (l's complement).
834 **^^defined** *symbol* True if symbol has a value.
835 **^^referenced** *symbol* True if symbol has been referenced.
836 **^^streq** *string1*, *string2* True if the strings are equal.
837 **^^macdef** *macroName* True if the macro is defined.
838 **^^abscount** Returns the size of current .abs section
839 **^^filesize** *string_filename* Returns the file size of supplied filename
840 ================================ ==========================================
842 * The boolean operators generate the value 1 if the expression is true, and 0 if it is not.
844 * A symbol is referenced if it is involved in an expression.
846 any combination of attributes: undefined and unreferenced, defined and unref-
847 erenced (i.e. declared but never used), undefined and referenced (in the case
848 of a forward or external reference), or defined and referenced.
855 =========== ==============================================
857 =========== ==============================================
858 \ + - * / The usual arithmetic operators.
859 % Modulo. Do *not* attempt to modulo by 0 or 1.
860 & | ^ Bit-wise **AND**, **OR** and **Exclusive-OR**.
861 << >> Bit-wise shift left and shift right.
862 < <= >= > Boolean magnitude comparisons.
864 <> != Boolean inequality.
865 =========== ==============================================
867 * All binary operators have the same precedence:
868 expressions are evaluated strictly left to right,
869 with the exception of the **-4** switch. For more information
870 refer to `Order of Evaluation`_.
872 * Division or modulo by zero yields an assembly error.
874 * The "<>" and "!=" operators are synonyms.
876 * Note that the modulo operator (%) is also used to introduce binary constants
877 (see: `Constants`_). A percent sign should be followed by at least one space if
878 it is meant to be a modulo operator, and is followed by a '0' or '1'.
883 ============ =========================================
884 Special Form Description
885 ============ =========================================
886 **^^date** The current system date (Gemdos format).
887 **^^time** The current system time (Gemdos format).
888 ============ =========================================
890 * The "**^^date**" special form expands to the current system date, in Gemdos
891 format. The format is a 16-bit word with bits 0 ...4 indicating the day of the
892 month (1...31), bits 5...8 indicating the month (1...12), and bits 9...15
893 indicating the year since 1980, in the range 0...119.
895 * The "**^^time**" special form expands to the current system time, in Gemdos
896 format. The format is a 16-bit word with bits 0...4 indicating the current
897 second divided by 2, bits 5...10 indicating the current minute 0...59. and
898 bits 11...15 indicating the current hour 0...23.
900 `Example Expressions`_
901 ''''''''''''''''''''''
905 line address contents source code
906 ---- ------- -------- -------------------------------
907 1 00000000 4480 lab1: neg.l d0
908 2 00000002 427900000000 lab2: clr.w lab1
909 3 =00000064 equ1 = 100
910 4 =00000096 equ2 = equ1 + 50
911 5 00000008 00000064 dc.l lab1 + equ1
912 6 0000000C 7FFFFFE6 dc.l (equl + ~equ2) >> 1
913 7 00000010 0001 dc.w ^^defined equl
914 8 00000012 0000 dc.w ^^referenced lab2
915 9 00000014 00000002 dc.l lab2
916 10 00000018 0001 dc.w ^^referenced lab2
917 11 0000001A 0001 dc.w lab1 = (lab2 - 6)
919 Lines 1 through four here are used to set up the rest of the example. Line 5 deposits
920 a relocatable pointer to the location 100 bytes beyond the label "**lab1**". Line 6 is
921 a nonsensical expression that uses the and right-shift operators. Line 7 deposits
922 a word of 1 because the symbol "**equ1**" is defined (in line 3).
924 Line 8 deposits a word of 0 because the symbol "**lab2**", defined in line 2, has
925 not been referenced. But the expression in line 9 references the symbol "**lab2**", so
926 line 10 (which is a copy of line-8) deposits a word of 1. Finally, line 11 deposits a
927 word of 1 because the Boolean equality operator evaluates to true.
929 The operators "**^^defined**" and "**^^referenced**" are particularly useful in
930 conditional assembly. For instance, it is possible to automatically include debugging
931 code if the debugging code is referenced, as in:
935 lea string,a0 ; AO -> message
936 jsr debug ; print a message
938 string: dc.b "Help me, Spock!",0 ; (the message)
942 .iif ^^referenced debug, .include "debug.s"
944 The **jsr** statement references the symbol debug. Near the end of the source file, the
945 "**.iif**" statement includes the file "**debug.s**" if the symbol debug was referenced.
947 In production code, presumably all references to the debug symbol will be removed,
948 and the debug source file will not be included. (We could have as easily made the
949 symbol **debug** external, instead of including another source file).
955 Assembler directives may be any mix of upper- or lowercase. The leading periods
956 are optional, though they are shown here and their use is encouraged. Directives
957 may be preceeded by a label; the label is defined before the directive is executed.
958 Some directives accept size suffixes (**.b**, **.s**, **.w**, **.1**, **.d**, **.x**, **.p**, or **.q**);
959 the default is word (**.w**) if no size is specified. The **.s** suffix is identical to **.b**,
960 with the exception of being used in a **dc** statement. In that case the **.s**
961 refers to single precision floating point numbers.
962 Directives relating to the 6502 are described in the chapter on `6502 Support`_.
968 If the location counter for the current section is odd, make it even by adding
969 one to it. In text and data sections a zero byte is deposited if necessary.
973 Align the program counter to the next integral long boundary (4 bytes).
974 Note that GPU/DSP code sections are not contained in their own
975 segments and are actually part of the TEXT or DATA segments.
976 Therefore, to align GPU/DSP code, align the current section before and
977 after the GPU/DSP code.
980 This directive is similar to the standard ‘C’ library printf() function
981 and is used to print user messages from the assembly process. You can
982 print any string or valid expression. Several format flags that can be used
983 to format your output are also supported.
999 .print “Mask: $”,/x/w MASK
1000 .print “Value: “,/d/l VALUE
1004 Align the program counter to the next integral phrase boundary (8 bytes).
1005 Note that GPU/DSP code sections are not contained in their own
1006 segments and are actually part of the TEXT or DATA segments.
1007 Therefore, to align GPU/DSP code, align the current section before and
1008 after the GPU/DSP code.
1012 Align the program counter to the next integral double phrase boundary (16
1013 bytes). Note that GPU/DSP code sections are not contained in their own
1014 segments and are actually part of the TEXT or DATA segments.
1015 Therefore, to align GPU/DSP code, align the current section before and
1016 after the GPU/DSP code.
1020 Align the program counter to the next integral quad phrase boundary (32
1021 bytes). Note that GPU/DSP code sections are not contained in their own
1022 segments and are actually part of the TEXT or DATA segments.
1023 Therefore, to align GPU/DSP code, align the current section before and
1024 after the GPU/DSP code.
1026 **.assert** *expression* [,\ *expression*...]
1028 Assert that the conditions are true (non-zero). If any of the comma-seperated
1029 expressions evaluates to zero an assembler warning is issued. For example:
1033 .assert *-start = $76
1034 .assert stacksize >= $400
1042 Switch to the BSS, data or text segments. Instructions and data may not
1043 be assembled into the BSS-segment, but symbols may be defined and storage
1044 may be reserved with the **.ds** directive. Each assembly starts out in the text
1053 Enable different flavours of the MC68000 family of CPUs. Bear in mind that not all
1054 instructions and addressing modes are available in all CPUs so the correct CPU
1055 should be selected at all times. Notice that it is possible to switch CPUs
1061 Enable FPU support. Note that *.68882* is on by default when selecting *.68030*.
1065 Switch to Motorola DSP56001 mode.
1067 **.org** *location* [*X:*/*Y:*/*P:*/*L:*]
1069 This directive sets the value of the location counter (or **pc**) to location, an
1070 expression that must be defined and absolute. It is legal to use the directive in
1071 the following modes: 6502, Tom, Jerry, OP, 56001 and 680x0 (only with -fr switch).
1072 Especially for the 56001 mode the *location* field **must** be prefixed with the
1073 intended section (*X:*, *Y:*, *P:* or *L:*).
1080 These directives control the optimisations that rmac applies to the source
1081 automatically. Each directive is applied immediately from the line encountered
1082 onwards. So it is possible to turn specific optimisations on and off globally
1083 (when placed at the start of the first file) or locally (by turning desired
1084 optimisations on and off at certain parts of the source). For a list of the
1085 optimisations (*n*) available please consult the table in section `The Command Line`_.
1087 **all**, as expected, turns all available optimisations on or off. An exception to this
1088 is *o10*/*op* as this is not an optimisation that should be turned on unless the user
1089 absolutely needs it.
1091 Lastly, as a "creature comfort" feature, if the first column of any line is prefixed
1092 with an exclamation mark (*!*) then for that line all optimisations are turned off.
1094 **.abs** [*location*]
1096 Start an absolute section, beginning with the specified location (or zero, if
1097 no location is specified). An absolute section is much like BSS, except that
1098 locations declared with .ds are based absolute. This directive is useful for
1099 declaring structures or hardware locations.
1100 For example, the following equates:
1110 could be as easily defined as:
1121 Another interesting example worth mentioning is the emulation of "C"'s "union" keyword
1122 using *.abs*. For example, the following "C" code:
1132 union { int spf_em_colour; int spf_emx_colour; };
1133 union { int spf_em_psmask[16]; int spf_emx_colouropt; };
1136 can be expressed as:
1141 *-------------------------------------------------------*
1142 spf_w: ds.w 1 ;<- common
1147 *-------------------------------------------------------*
1149 spf_em_colour: ds.l 1 ;<- union #1
1150 spf_em_psmask: ds.l 16
1151 *-------------------------------------------------------*
1155 spf_emx_colour: ds.l 1 ;<- union #2
1156 spf_emx_colouropt: ds.l 1
1157 spf_emx_psmask: ds.l 16
1158 spf_emx_psmaskopt: ds.l 16
1161 ;*-------------------------------------------------------*
1163 move #spf_em_colour,d0
1164 move #spf_emx_colour,d0
1166 In this example, *spf_em_colour* and *spf_emx_colour* will have the same value.
1168 **.comm** *symbol*, *expression*
1170 Specifies a label and the size of a common region. The label is made global,
1171 thus confined symbols cannot be made common. The linker groups all common
1172 regions of the same name; the largest size determines the real size of the
1173 common region when the file is linked.
1175 **.ccdef** *expression*
1177 Allows you to define names for the condition codes used by the JUMP
1178 and JR instructions for GPU and DSP code. For example:
1184 jump Always,(r3) ; 'Always' is actually 0
1186 **.ccundef** *regname*
1188 Undefines a register name (regname) previously assigned using the
1189 .CCDEF directive. This is only implemented in GPU and DSP code
1192 **.dc.i** *expression*
1194 This directive generates long data values and is similar to the DC.L
1195 directive, except the high and low words are swapped. This is provided
1196 for use with the GPU/DSP MOVEI instruction.
1198 **.dc**\ [.\ *size*] *expression* [, *expression*...]
1200 Deposit initialized storage in the current section. If the specified size is word
1201 or long, the assembler will execute a .even before depositing data. If the size
1202 is .b, then strings that are not part of arithmetic expressions are deposited
1203 byte-by-byte. If no size is specified, the default is .w. This directive cannot be
1204 used in the BSS section.
1206 **.dcb**\ [.\ *size*] *expression1*, *expression2*
1208 Generate an initialized block of *expression1* bytes, words or longwords of the
1209 value *expression2*. If the specified size is word or long, the assembler will
1210 execute .even before generating data. If no size is specified, the default is **.w**.
1211 This directive cannot be used in the BSS section.
1213 **.ds**\ [.\ *size*] *expression*
1215 Reserve space in the current segment for the appropriate number of bytes,
1216 words or longwords. If no size is specified, the default size is .w. If the size
1217 is word or long, the assembler will execute .even before reserving space.
1221 Switch to Jaguar DSP assembly mode. This directive must be used
1222 within the TEXT or DATA segments.
1224 **.init**\ [.\ *size*] [#\ *expression*,]\ *expression*\ [.\ *size*] [,...]
1226 Generalized initialization directive. The size specified on the directive becomes
1227 the default size for the rest of the line. (The "default" default size is **.w**.) A
1228 comma-seperated list of expressions follows the directive; an expression may be
1229 followed by a size to override the default size. An expression may be preceeded
1230 by a sharp sign, an expression and a comma, which specifies a repeat count to
1231 be applied to the next expression. For example:
1235 .init.l -1, 0.w, #16,'z'.b, #3,0, 11.b
1237 will deposit a longword of -1, a word of zero, sixteen bytes of lower-case 'z',
1238 three longwords of zero, and a byte of 11.
1240 No auto-alignment is performed within the line, but a **.even** is done once
1241 (before the first value is deposited) if the default size is word or long.
1243 **.cargs** [#\ *expression*,] *symbol*\ [.\ *size*] [, *symbol*\ [.\ *size*].. .]
1245 Compute stack offsets to C (and other language) arguments. Each symbol is
1246 assigned an absolute value (like equ) which starts at expression and increases
1247 by the size of each symbol, for each symbol. If the expression is not supplied,
1248 the default starting value is 4. For example:
1252 .cargs #8, .fileliams.1, .openMode, .butPointer.l
1254 could be used to declare offsets from A6 to a pointer to a filename, a word
1255 containing an open mode, and a pointer to a buffer. (Note that the symbols
1256 used here are confined). Another example, a C-style "string-length" function,
1257 could be written as:
1261 _strlen:: .cargs .string ; declare arg
1262 move.l .string(sp),a0 ; a0 -> string
1263 moveq #-1,d0 ; initial size = -1
1264 .1: addq.1 #1,d0 ; bump size
1265 tst.b (a0)+ ; at end of string?
1266 bne .1 ; (no -- try again)
1267 rts ; return string length
1269 **.error** ["*string*"]
1271 Aborts the build, optionally printing a user defined string. Can be useful
1272 inside conditional assembly blocks in order to catch errors. For example:
1276 .if ^^defined JAGUAR
1277 .error "TOS cannot be built on Jaguar, don't be silly"
1282 End the assembly. In an include file, end the include file and resume assembling
1283 the superior file. This statement is not required, nor are warning messages
1284 generated if it is missing at the end of a file. This directive may be used inside
1285 conditional assembly, macros or **.rept** blocks.
1287 **.equr** *expression*
1289 Allows you to name a register. For example:
1296 add ClipW,r0 ; ClipW actually is r19
1298 **.if** *expression*
1304 Start a block of conditional assembly. If the expression is true (non-zero) then
1305 assemble the statements between the .if and the matching **.endif** or **.else**.
1306 If the expression is false, ignore the statements unless a matching .else is
1307 encountered. Conditional assembly may be nested to any depth.
1309 It is possible to exit a conditional assembly block early from within an include
1310 file (with **end**) or a macro (with **endm**).
1312 **.iif** *expression*, *statement*
1314 Immediate version of **.if**. If the expression is true (non-zero) then the state-
1315 ment, which may be an instruction, a directive or a macro, is executed. If
1316 the expression is false, the statement is ignored. No **.endif** is required. For
1321 .iif age < 21, canDrink = 0
1322 .iif weight > 500, dangerFlag = 1
1323 .iif !(^^defined DEBUG), .include dbsrc
1325 **.macro** *name* [*formal*, *formal*,...]
1331 Define a macro called name with the specified formal arguments. The macro
1332 definition is terminated with a **.endm** statement. A macro may be exited early
1333 with the .exitm directive. See the chapter on `Macros`_ for more information.
1335 **.undefmac** *macroName* [, *macroName*...]
1337 Remove the macro-definition for the specified macro names. If reference is
1338 made to a macro that is not defined, no error message is printed and the name
1341 **.rept** *expression*
1345 The statements between the **.rept** and **.endr** directives will be repeated *expression*
1346 times. If the expression is zero or negative, no statements will be
1347 assembled. No label may appear on a line containing either of these directives.
1349 **.globl** *symbol* [, *symbol*...]
1351 **.extern** *symbol* [, *symbol*...]
1353 Each symbol is made global. None of the symbols may be confined symbols
1354 (those starting with a period). If the symbol is defined in the assembly, the
1355 symbol is exported in the object file. If the symbol is undefined at the end
1356 of the assembly, and it was referenced (i.e. used in an expression), then the
1357 symbol value is imported as an external reference that must be resolved by the
1358 linker. The **.extern** directive is merely a synonym for **.globl**.
1360 **.include** "*file*"
1362 Include a file. If the filename is not enclosed in quotes, then a default extension
1363 of "**.s**" is applied to it. If the filename is quoted, then the name is not changed
1366 Note: If the filename is not a valid symbol, then the assembler will generate an
1367 error message. You should enclose filenames such as "**atari.s**" in quotes,
1368 because such names are not symbols.
1370 If the include file cannot be found in the current directory, then the directory
1371 search path, as specified by -i on the commandline, or' by the 'RMACPATH'
1372 enviroment string, is traversed.
1374 **.incbin** "*file*" [, [*size*], [*offset*]]
1376 Include a file as a binary. This can be thought of a series of **dc.b** statements
1377 that match the binary bytes of the included file, inserted at the location of the
1378 directive. The directive is not allowed in a BSS section. Optional parameters
1379 control the amount of bytes to be included and offset from the start of the file.
1380 All the following lines are valid:
1383 .incbin "test.bin" ; Include the whole file
1384 .incbin "test.bin",,$30 ; Skip the first 48 bytes
1385 .incbin "test.bin",$70,$30 ; Include $70 bytes starting at offset $30
1386 .incbin "test.bin",$48 ; Include the file starting at offset 48 till the end
1387 .incbin "test.bin",, ; Include the whole file
1391 Issue a page eject in the listing file.
1393 **.title** "*string*"
1395 **.subttl** [-] "*string*"
1397 Set the title or subtitle on the listing page. The title should be specified on
1398 the the first line of the source program in order to take effect on the first page.
1399 The second and subsequent uses of **.title** will cause page ejects. The second
1400 and subsequent uses of .subttl will cause page ejects unless the subtitle string
1401 is preceeded by a dash (-).
1407 Enable or disable source code listing. These directives increment and decrement
1408 an internal counter, so they may be appropriately nested. They have no effect
1409 if the **-l** switch is not specified on the commandline.
1413 This directive provides unstructured flow of control within a macro definition.
1414 It will transfer control to the line of the macro containing the specified goto
1415 label. A goto label is a symbol preceeded by a colon that appears in the first
1416 column of a source line within a macro definition:
1420 where the label itself can be any valid symbol name, followed immediately by
1421 whitespace and a valid source line (or end of line). The colon **must** appear in
1424 The goto-label is removed from the source line prior to macro expansion -
1425 to all intents and purposes the label is invisible except to the .goto directive
1426 Macro expansion does not take place within the label.
1428 For example, here is a silly way to count from 1 to 10 without using **.rept**:
1436 iif count <= 10, goto loop
1441 Switch to Jaguar GPU assembly mode. This directive must be used
1442 within the TEXT or DATA segments.
1446 No. Just... no. Don't ask about it. Ever.
1448 **.prgflags** *value*
1450 Sets ST executable .PRG field *PRGFLAGS* to *value*. *PRGFLAGS* is a bit field defined as follows:
1452 ============ ====== =======
1453 Definition Bit(s) Meaning
1454 ============ ====== =======
1455 PF_FASTLOAD 0 If set, clear only the BSS area on program load, otherwise clear the entire heap.
1456 PF_TTRAMLOAD 1 If set, the program may be loaded into alternative RAM, otherwise it must be loaded into standard RAM.
1457 PF_TTRAMMEM 2 If set, the program's Malloc() requests may be satisfied from alternative RAM, otherwise they must be satisfied from standard RAM.
1458 -- 3 Currently unused.
1459 See left. 4 & 5 If these bits are set to 0 (PF_PRIVATE), the processes' entire memory space will be considered private (when memory protection is enabled).If these bits are set to 1 (PF_GLOBAL), the processes' entire memory space will be readable and writable by any process (i.e. global).If these bits are set to 2 (PF_SUPERVISOR), the processes' entire memory space will only be readable and writable by itself and any other process in supervisor mode.If these bits are set to 3 (PF_READABLE), the processes' entire memory space will be readable by any application but only writable by itself.
1460 -- 6-15 Currently unused.
1461 ============ ====== =======
1463 **.regequ** *expression*
1464 Essentially the same as **.EQUR.** Included for compatibility with the GASM
1468 Essentially the same as **.EQURUNDEF.** Included for compatibility with
1477 All of the standard Motorola 68000 mnemonics and addressing modes are supported;
1478 you should refer to **The Motorola M68000 Programmer's Reference Manual**
1479 for a description of the instruction set and the allowable addressing modes for each
1480 instruction. With one major exception (forward branches) the assembler performs
1481 all the reasonable optimizations of instructions to their short or address register
1484 Register names may be in upper or lower case. The alternate forms ``R0`` through
1485 ``R15`` may be used to specify ``D0`` through ``A7``. All register names are keywords, and
1486 may not be used as labels or symbols. None of the 68010 or 68020 register names
1487 are keywords (but they may become keywords in the future).
1492 ===================================== ===========================================
1493 Assembler Syntax Description
1494 ===================================== ===========================================
1495 *Dn* Data register direct
1496 *An* Address register direct
1497 (*An*) Address register indirect
1498 (*An*)+ Address register indirect postincrement
1499 -(*An*) Address register indirect predecrement
1500 *disp*\ (*An*) Address register indirect with displacement
1501 *bdisp*\ (*An*, *Xi*\ [.\ *size*]) Address register indirect indexed
1502 *abs*.w Absolute short
1503 *abs* Absolute (long or short)
1504 *abs*.l Forced absolute long
1505 *disp*\ (PC) Program counter with displacement
1506 *bdisp*\ (PC, *Xi*\ ) Program counter indexed
1508 ===================================== ===========================================
1510 `68020+ Addressing Modes`_
1511 ''''''''''''''''''''''''''
1513 The following addressing modes are only valid for 68020 and newer CPUs. In these
1514 modes most of the parameters like Base Displacement (**bd**), Outer Displacement
1515 (**od**), Base Register (**An**) and Index Register (**Xn**) can be omitted. RMAC
1516 will detect this and *suppress* the registers in the produced code.
1519 use a special syntax to denote register suppression like **Zan** to suppress the Base
1520 Register and **Rin** to suppress the Index Register. RMAC has no support for this
1521 behaviour nor needs it to suppress registers.
1523 In addition, other assemblers will allow reordering of the parameters (for example
1524 ([*An*,\ *bd*])). This is not allowed in RMAC.
1526 Also noteworthy is that the Index Register can be an address or data register.
1528 To avoid internal confusion the 68040/68060 registers *DC*, *IC* and *BC* are named
1529 *DC40*, *IC40* and *BC40* respectively.
1531 ====================================================== =============================================================
1532 Assembler Syntax Description
1533 ====================================================== =============================================================
1534 *bd*\ (*An*, *Xi*\ [.\ *size*][*\*scale*]) Address register indirect indexed
1535 ([*bd*,\ *An*],\ *Xn*\[.\ *siz*][*\*scale*],\ *od*) Register indirect preindexed with outer displacement
1536 ([*bd*,\ *An*,\ *Xn*\[.\ *siz*][*\*scale*],\ *od*) Register indirect postindexed with outer displacement
1537 ([*bd*,\ *PC*],\ *Xn*\[.\ *siz*][*\*scale*],\ *od*) Program counter indirect preindexed with outer displacement
1538 ([*bd*,\ *PC*,\ *Xn*\[.\ *siz*][*\*scale*],\ *od*) Program counter indirect postindexed with outer displacement
1539 ====================================================== =============================================================
1543 Since RMAC is a one pass assembler, forward branches cannot be automatically
1544 optimized to their short form. Instead, unsized forward branches are assumed to
1545 be long. Backward branches are always optimized to the short form if possible.
1547 A table that lists "extra" branch mnemonics (common synonyms for the Motorola
1548 defined mnemonics) appears below.
1550 `Linker Constraints`_
1551 '''''''''''''''''''''
1552 It is not possible to make an external reference that will fix up a byte. For example:
1557 move.l frog(pc,d0),d1
1559 is illegal (and generates an assembly error) when frog is external, because the
1560 displacement occupies a byte field in the 68000 offset word, which the object file
1565 ============== ========
1566 Alternate name Becomes:
1567 ============== ========
1577 ============== ========
1579 `Optimizations and Translations`_
1580 '''''''''''''''''''''''''''''''''
1581 The assembler provides "creature comforts" when it processes 68000 mnemonics:
1583 * **CLR.x An** will really generate **SUB.x An,An**.
1585 * **ADD**, **SUB** and **CMP** with an address register will really generate **ADDA**,
1586 **SUBA** and **CMPA**.
1588 * The **ADD**, **AND**, **CMP**, **EOR**, **OR** and **SUB** mnemonics with immediate
1589 first operands will generate the "I" forms of their instructions (**ADDI**, etc.) if
1590 the second operand is not register direct.
1592 * All shift instructions with no count value assume a count of one.
1594 * **MOVE.L** is optimized to **MOVEQ** if the immediate operand is defined and
1595 in the range -128...127. However, **ADD** and **SUB** are never translated to
1596 their quick forms; **ADDQ** and **SUBQ** must be explicit.
1598 * All optimisations are controllable using the **.opt** directive. Refer to its
1599 description in section `Directives`_.
1601 * All optimisations are turned off for any source line that has an exclamation mark
1602 (*!*) on their first column.
1604 * Optimisation switch 11 is turned on by default for compatibility with the
1605 Motorola reference 56001 DSP assembler.
1606 All other levels are off by default. (refer to section `The Command Line`_
1607 for a description of all the switches).
1609 * Optimisation warnings are off by default. Invoke RMAC with the *-s* switch to
1610 turn on warnings in console and listing output.
1612 * In GPU/DSP code sections, you can use JUMP (Rx) in place of JUMP T, (Rx) and JR
1613 (Rx) in place of JR T,(Rx).
1615 * RMAC tests all GPU/DSP restrictions and corrects them wherever possible (such as
1616 inserting a NOP instruction when needed).
1618 * The *(Rx+N)* addressing mode for GPU/DSP instructions is optimized to *(Rx)*
1623 `Macro declaration`_
1624 ''''''''''''''''''''
1625 A macro definition is a series of statements of the form:
1628 .macro name [ formal-arg, ...]
1632 statements making up the macro body
1638 The name of the macro may be any valid symbol that is not also a 68000 instruction
1639 or an assembler directive. (The name may begin with a period - macros cannot
1640 be made confined the way labels or equated symbols can be). The formal argument
1641 list is optional; it is specified with a comma-seperated list of valid symbol names.
1642 Note that there is no comma between the name of the macro and the name of the
1643 first formal argument. It is not advised to begin an argument name with a numeric
1646 A macro body begins on the line after the **.macro** directive. All instructions
1647 and directives, except other macro definitions, are legal inside the body.
1649 The macro ends with the **.endm** statement. If a label appears on the line with
1650 this directive, the label is ignored and a warning is generated.
1652 `Parameter Substitution`_
1653 '''''''''''''''''''''''''
1654 Within the body, formal parameters may be expanded with the special forms:
1660 The second form (enclosed in braces) can be used in situations where the characters
1661 following the formal parameter name are valid symbol continuation characters. This
1662 is usually used to force concatentation, as in:
1667 \(godzilla}vs\{reagan}
1669 The formal parameter name is terminated with a character that is not valid in
1670 a symbol (e.g. whitespace or puncuation); optionally, the name may be enclosed in
1671 curly-braces. The names must be symbols appearing on the formal argument list,
1672 or a single decimal digit (``\1`` corresponds to the first argument, ``\2`` to the second,
1673 ``\9`` to the ninth, and ``\0`` to the tenth). It is possible for a macro to have more than
1674 ten formal arguments, but arguments 11 and on must be referenced by name, not
1677 Other special forms are:
1679 ============ ================================================
1680 Special Form Description
1681 ============ ================================================
1682 ``\\`` a single "\",
1683 ``\~`` a unique label of the form "Mn"
1684 ``\#`` the number of arguments actually specified
1685 ``\!`` the "dot-size" specified on the macro invocation
1686 ``\?name`` conditional expansion
1687 ``\?{name}`` conditional expansion
1688 ============ ================================================
1690 The last two forms are identical: if the argument is specified and is non-empty, the
1691 form expands to a "1", otherwise (if the argument is missing or empty) the form
1694 The form "``\!``" expands to the "dot-size" that was specified when the macro
1695 was invoked. This can be used to write macros that behave differently depending
1696 on the size suffix they are given, as in this macro which provides a synonym for the
1701 .macro deposit value
1704 deposit.b 1 ; byte of 1
1705 deposit.w 2 ; word of 2
1706 deposit.l 3 ; longvord of 3
1707 deposit 4 ; word of 4 (no explicit size)
1711 A previously-defined macro is called when its name appears in the operation field of
1712 a statement. Arguments may be specified following the macro name; each argument
1713 is seperated by a comma. Arguments may be empty. Arguments are stored for
1714 substitution in the macro body in the following manner:
1716 * Numbers are converted to hexadecimal.
1718 * All spaces outside strings are removed.
1720 * Keywords (such as register names, dot sizes and "^^" operators) are converted
1723 * Strings are enclosed in double-quote marks (").
1725 For example, a hypothetical call to the macro "``mymacro``", of the form:
1726 ``mymacro A0, , 'Zorch' / 32, "^^DEFINED foo, , , tick tock``
1728 will result in the translations:
1730 ======== ================= =================================================
1731 Argument Expansion Comment
1732 ======== ================= =================================================
1733 ``\1`` ``a0`` "``A0``" converted to lower-case
1735 ``\3`` ``"Zorch"/$20`` "``Zorch``" in double-quotes, 32 in hexadecimal
1736 ``\4`` ``^^defined foo`` "``^^DEFINED``" converted to lower-case
1739 ``\7`` ``ticktock`` spaces removed (note concatenation)
1740 ======== ================= =================================================
1742 The **.exitm** directive will cause an immediate exit from a macro body. Thus
1743 the macro definition:
1748 .iif !\?source, .exitm ; exit if source is empty
1749 move \source,d0 ; otherwise, deposit source
1752 will not generate the move instruction if the argument **"source"** is missing from
1753 the macro invocation.
1755 The **.end**, **.endif** and **.exitm** directives all pop-out of their include levels
1756 appropriately. That is, if a macro performs a **.include** to include a source file, an
1757 executed **.exitm** directive within the include-file will pop out of both the include-file
1760 Macros may be recursive or mutually recursive to any level, subject only to
1761 the availability of memory. When writing recursive macros, take care in the coding
1762 of the termination condition(s). A macro that repeatedly calls itself will cause the
1763 assembler to exhaust its memory and abort the assembly.
1768 The Gemdos macro is used to make file system calls. It has two parameters, a
1769 function number and the number of bytes to clean off the stack after the call. The
1770 macro pushes the function number onto the stack and does the trap to the file
1771 system. After the trap returns, conditional assembly is used to choose an addq or
1772 an **add.w** to remove the arguments that were pushed.
1776 .macro Gemdos trpno, clean
1777 move.w #\trpno,-(sp) ; push trap number
1778 trap #1 ; do GEMDOS trap
1780 addq #\clean,sp ; clean-up up to 8 bytes
1782 add.w #\clean,sp ; clean-up more than 8 bytes
1786 The Fopen macro is supplied two arguments; the address of a filename, and
1787 the open mode. Note that plain move instructions are used, and that the caller of
1788 the macro must supply an appropriate addressing mode (e.g. immediate) for each
1793 .macro Fopen file, mode
1794 movs.w \mode,-(sp) ;push open mode
1795 move.1 \file,-(sp) ;push address of tile name
1796 Gemdos $3d,8 ;do the GEMDOS call
1799 The **String** macro is used to allocate storage for a string, and to place the
1800 string's address somewhere. The first argument should be a string or other expres-
1801 sion acceptable in a dc.b directive. The second argument is optional; it specifies
1802 where the address of the string should be placed. If the second argument is omitted,
1803 the string's address is pushed onto the stack. The string data itself is kept in the
1808 .macro String str,loc
1809 .if \?loc ; if loc is defined
1810 move.l #.\~,\loc ; put the string's address there
1812 pea .\~ ; push the string's address
1814 .data ; put the string data
1815 .\~: dc.b \str,0 ; in the data segment
1816 .text ; and switch back to the text segment
1819 The construction "``.\~``" will expand to a label of the form "``.M``\ *n*" (where *n* is
1820 a unique number for every macro invocation), which is used to tag the location of
1821 the string. The label should be confined because the macro may be used along with
1822 other confined symbols.
1824 Unique symbol generation plays an important part in the art of writing fine
1825 macros. For instance, if we needed three unique symbols, we might write "``.a\~``",
1826 "``.b\~``" and "``.c\~``".
1830 Repeat-blocks provide a simple iteration capability. A repeat block allows a range
1831 of statements to be repeated a specified number of times. For instance, to generate
1832 a table consisting of the numbers 255 through 0 (counting backwards) you could
1837 .count set 255 ; initialize counter
1838 .rept 256 ; repeat 256 times:
1839 dc.b .count ; deposit counter
1840 .count set .count - 1 ; and decrement it
1841 .endr ; (end of repeat block)
1843 Repeat blocks can also be used to duplicate identical pieces of code (which are
1844 common in bitmap-graphics routines). For example:
1848 .rept 16 ; clear 16 words
1849 clr.w (a0)+ ; starting at AO
1852 `Jaguar GPU/DSP Mode`_
1853 ======================
1855 RMAC will generate code for the Atari Jaguar GPU and DSP custom RISC (Reduced
1856 Instruction Set Computer) processors. See the Atari Jaguar Software reference Manual - Tom
1857 & Jerry for a complete listing of Jaguar GPU and DSP assembler mnemonics and addressing
1862 The following condition codes for the GPU/DSP JUMP and JR instructions are built-in:
1866 CC (Carry Clear) = %00100
1867 CS (Carry Set) = %01000
1870 NE (Not Equal) = %00001
1872 HI (Higher) = %00101
1875 `Jaguar Object Processor Mode`_
1876 ===============================
1881 An assembler to generate object lists for the Atari Jaguar's Object processor.
1887 To really utilize the OP properly, it needs an assembler. Otherwise, what
1888 happens is you end up writing an assembler in your code to assemble the OP
1889 list, and that's a real drag--something that *should* be handled by a proper
1894 ''''''''''''''''''''
1896 The OP assembler works similarly to the RISC assembler; to enter the OP
1897 assembler, you put the .objproc directive in your code (N.B.: like the RISC
1898 assembler, it only works in a TEXT or DATA section). From there, you build
1899 the OP list how you want it and go from there. A few caveats: you will want
1900 to put a .org directive at the top of your list, and labels that you want to
1901 be able to address in 68xxx code (for moving from a data section to an
1902 address where it will be executed by the OP, for example) should be created
1906 `What are the opcodes?`_
1907 ''''''''''''''''''''''''
1909 They are **bitmap**, **scbitmap**, **gpuobj**, **branch**, **stop**, **nop**, and **jump**. **nop** and **jump**
1910 are psuedo-ops, they are there as a convenience to the coder.
1913 `What are the proper forms for these opcodes?`_
1914 '''''''''''''''''''''''''''''''''''''''''''''''
1916 They are as follows:
1918 **bitmap** *data addr*, *xloc*, *yloc*, *dwidth*, *iwidth*, *iheight*, *bpp*,
1919 *pallete idx*, *flags*, *firstpix*, *pitch*
1921 **scbitmap** *data addr*, *xloc*, *yloc*, *dwidth*, *iwidth*, *iheight*,
1922 *xscale*, *yscale*, *remainder*, *bpp*, *pallete idx*,
1923 *flags*, *firstpix*, *pitch*
1925 **gpuobj** *line #*, *userdata* (bits 14-63 of this object)
1927 **branch** VC *condition (<, =, >)* *line #*, *link addr*
1929 **branch** OPFLAG, *link addr*
1931 **branch** SECHALF, *link addr*
1937 **jump** *link addr*
1939 Note that the *flags* field in bitmap and scbitmap objects consist of the
1940 following: **REFLECT**, **RMW**, **TRANS**, **RELEASE**. They can be in any order (and
1941 should be separated by whitespace **only**), and you can only put a maximum of
1942 four of them in. Further note that with bitmap and scbitmap objects, all the
1943 parameters after *data addr* are optional--if they are omitted, they will
1944 use defaults (mostly 0, but 1 is the default for pitch). Also, in the
1945 scbitmap object, the *xscale*, *yscale*, and *remainder* fields can be
1946 floating point constants/expressions. *data addr* can refer to any address
1947 defined (even external!) and the linker (rln v1.6.0 or greater) will
1948 properly fix up the address.
1954 Pretty much what you expect. It's beyond the scope of this little note to
1955 explain the Jaguar's Object Processor and how it operates, so you'll have to
1956 seek explanations for how they work elsewhere.
1959 `Why do I want to put a *.org* directive at the top of my list?`_
1960 '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1962 You want to put a *.org* directive at the top of your list because otherwise
1963 the assembler will not know where in memory the object list is supposed
1964 go--then when you move it to its destination, the object link addresses will
1965 all be wrong and it won't work.
1968 `Why would I copy my object list to another memory location?`_
1969 ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1971 Simple: because the OP destroys the list as it uses it to render the screen.
1972 If you don't keep a fresh copy stashed away somewhere to refresh it before
1973 the next frame is rendered, what you see on the screen will not be what you
1974 expect, as the OP has scribbled all over it!
1977 `Does the assembler do anything behind my back?`_
1978 '''''''''''''''''''''''''''''''''''''''''''''''''
1980 Yes, it will emit **NOP** s to ensure that bitmaps and scbitmaps are on proper
1981 memory boundaries, and fixup link addresses as necessary. This is needed
1982 because of a quirk in how the OP works (it ORs constants on the address
1983 lines to get the phrases it needs and if they are not zeroes, it will fail
1984 in bizarre ways). It will also set all *ypos* constants on the correct
1985 half-line (as that's how the OP views them).
1988 `Why can't I define the link addresses for all the objects?`_
1989 '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1991 You really, *really* don't want to do this. Trust me on this one.
1993 `How about an example of an object list?`_
1994 ''''''''''''''''''''''''''''''''''''''''''
2002 objects: ; This is the label you will use to address this in 68K code
2003 .objproc ; Engage the OP assembler
2004 .org objList ; Tell the OP assembler where the list will execute
2006 branch VC < 69, .stahp ; Branch to the STOP object if VC < 69
2007 branch VC > 241, .stahp ; Branch to the STOP object if VC > 241
2008 bitmap bRAM, 22, 70, 24, 24, 22, 4
2009 bitmap bRAM, 20+96+96, 70, 24, 24, 22, 4, 0, REFLECT
2010 scbitmap tms, 20, 70, 1, 1, 8, 3.0, 3.0, 2.9999, 0, 0, TRANS
2011 scbitmap tmsShadow, 23, 73, 1, 1, 8, 3.0, 3.0, 2.9999, 0, 3, TRANS
2012 bitmap sbRelBM, 30, 108, 3, 3, 8, 0, 1, TRANS
2013 bitmap txt1BM, 46, 132, 3, 3, 8, 0, 2, TRANS
2014 bitmap txt2BM, 46, 148, 3, 3, 8, 0, 2, TRANS
2015 bitmap txt3BM, 22, 164, 3, 3, 8, 0, 2, TRANS
2026 RMAC fully supports Motorola's DSP56001 as used on the Atari Falcon and can output
2027 binary code in the two most popular formats: *.lod* (ASCII dump, supported by the
2028 Atari Falcon XBIOS) and *.p56* (binary equivalent of *.lod*)
2030 `Differences from Motorola's assembler`_
2031 ''''''''''''''''''''''''''''''''''''''''
2033 - Motorola's assembler aliases **and #xxx,reg** with **andi #xxx,reg** and can
2034 distinguish between the two. rmac needs the user to be explicit and will
2035 generate an error if the programmer tries to use syntax from one instruction
2037 - Similarly Motorola's assembler can alias **move** with **movec**, **movep**
2038 and **movem**. rmac also not accept such aliasing and generate an error.
2039 - Motorola's assembler uses the underscore character (*_*) to define local
2040 labels. In order for rmac to maintain a uniform syntax across all platforms,
2041 such labels will not be treated as local.
2042 - Macros syntax is different from Motorola's assembler. This includes local
2043 labels inside macros. The user is encouraged to study the `Macros`_ section
2044 and compare syntactical differences.
2045 - Motorola's assembler allows reordering of addressing modes **x:**, **x:r**,
2046 **r:y**, **x:y**. rmac will only accept syntax as is defined on the reference
2048 - In **L:** section a dc value cannot be 12 hex digits like Motorola's assmebler.
2049 Instead, the value needs to be split into two parts separated by **:**.
2053 RMAC will generate code for the MOS 6502 microprocessor. This chapter
2054 describes extra addressing modes and directives used to support the 6502.
2056 As the 6502 object code is not linkable (currently there is no linker) external
2057 references may not be made. (Nevertheless, RMAC may reasonably be used for
2058 large assemblies because of its blinding speed.)
2060 `6502 Addressing Modes`_
2061 ''''''''''''''''''''''''
2062 All standard 6502 addressing modes are supported, with the exception of the
2063 accumulator addressing form, which must be omitted (e.g. "ror a" becomes "ror").
2064 Five extra modes, synonyms for existing ones, are included for compatibility with
2065 the Atari Coinop assembler.
2067 ============== ========================================
2068 *empty* implied or accumulator (e.g. tsx or ror)
2069 *expr* absolute or zeropage
2071 #<\ *expr* immediate low byte of a word
2072 #>\ *expr* immediate high byte of a word
2073 (*expr*,x) indirect X
2074 (*expr*),y indirect Y
2078 @\ *expr*\ (x) indirect X
2079 @\ *expr*\ (y) indirect Y
2081 x,\ *expr* indexed X
2082 y,\ *expr* indexed Y
2083 ============== ========================================
2088 This directive enters the 6502 section. The location counter is undefined, and
2089 must be set with ".org" before any code can be generated.
2091 The "``dc.w``" directive will produce 6502-format words (low byte first). The
2092 68000's reserved keywords (``d0-d7/a0-a7/ssp/usp`` and so on) remain reserved
2093 (and thus unusable) while in the 6502 section. The directives **globl**, **dc.l**,
2094 **dcb.l**, **text**, **data**, **bss**, **abs**, **even** and **comm** are illegal in the 6502 section.
2095 It is permitted, though probably not useful, to generate both 6502 and 68000
2096 code in the same object file.
2098 This directive leaves the 6502 segment and returns to the 68000's text segment.
2099 68000 instructions may be assembled as normal.
2101 This directive sets the value of the location
2102 counter (or **pc**) to location, an expression that must be defined, absolute, and
2107 It is possible to assemble "beyond" the microprocessor's 64K address space, but
2108 attempting to do so will probably screw up the assembler. DO NOT attempt
2109 to generate code like this:
2118 the third NOP in this example, at location $10000, may cause the assembler
2119 to crash or exhibit spectacular schizophrenia. In any case, RMAC will give
2120 no warning before flaking out.
2122 `6502 Object Code Format`_
2123 ''''''''''''''''''''''''''
2124 Traditionally Madmac had a very kludgy way of storing object files. This has been
2125 replaced with a more standard *.exe* (or *.com* or *.xex* if you prefer). Briefly,
2126 the *.exe* format consists of chunks of this format (one after the other):
2131 00-01 $FFFF - Indicates a binary load file. Mandatory for first segment, optional for any other segment
2132 02-03 Start Address. The segment will load at this address
2133 04-05 End Address. The last byte to load for this segment
2134 06-.. The actual segment data to load (End Address-Start Address + 1 bytes)
2139 `When Things Go Wrong`_
2140 '''''''''''''''''''''''
2141 Most of RMAC's error messages are self-explanatory. They fall into four classes:
2142 warnings about situations that you (or the assembler) may not be happy about,
2143 errors that cause the assembler to not generate object files, fatal errors that cause
2144 the assembler to abort immediately, and internal errors that should never happen.\ [3]_
2146 You can write editor macros (or sed or awk scripts) to parse the error messages
2147 RMAC generates. When a message is printed, it is of the form:
2149 "*filename*" , ``line`` *line-number*: *message*
2151 The first element, a filename enclosed in double quotes, indicates the file that generated
2152 the error. The filename is followed by a comma, the word "``line``", and a line
2153 number, and finally a colon and the text of the message. The filename "**(\*top\*)**"
2154 indicates that the assembler could not determine which file had the problem.
2156 The following sections list warnings, errors and fatal errors in alphabetical
2157 order, along with a short description of what may have caused the problem.
2159 .. [3] If you come across an internal error, we would appreciate it if you would contact the rmac development team and let us know about the problem.
2163 **bad backslash code in string**
2164 You tried to follow a backslash in a string with a character that the assembler
2165 didn't recognize. Remember that RMAC uses a C-style escape system in
2168 You specified a label before a macro, **rept** or **endm** directive. The assembler
2169 is warning you that the label will not be defined in the assembly.
2170 **unoptimized short branch**
2171 This warning is only generated if the -s switch is specified on the command
2172 line. The message refers to a forward, unsized long branch that you could have
2179 As a result of previous errors, the assembler cannot continue processing. The
2180 assembly is aborted.
2181 **line too long as a result of macro expansion**
2182 When a source line within a macro was expanded, the resultant line was too
2183 long for RMAC (longer than 200 characters or so).
2186 **memory exhausted**
2187 The assembler ran out of memory. You should (1) split up your source files
2188 and assemble them seperately, or (2) if you have any ramdisks or RAM-resident
2189 programs (like desk accessories) decrease their size so that the assembler has
2190 more RAM to work with. As a rule of thumb, pure 68000 code will use up to
2191 twice the number of bytes contained in the source files, whereas 6502 code will
2192 use 64K of ram right away, plus the size of the source files. The assembler itself
2193 uses about 80K bytes. Get out your calculator...
2195 The assembler ran across an **endm** directive when it wasn't expecting to see
2196 one. The assembly is aborted. Check the nesting of your macro definitions -
2197 you probably have an extra **endm**.
2205 Syntax error in **.cargs** directive.
2207 **.comm symbol already defined**
2209 You tried to ``.comm`` a symbol that was already defined.
2211 **.init not permitted in BSS or ABS**
2213 You tried to use ``.init`` in the BSS or ABS section.
2215 **Cannot create:** *filename*
2217 The assembler could not create the indicated filename.
2219 **External quick reference**
2221 You tried to make the immediate operand of a **moveq**, **subq** or **addq** instruction external.
2223 **PC-relative expr across sections**
2225 You tried to make a PC-relative reference to a location contained in another
2228 **[bwsl] must follow '.' in symbol**
2230 You tried to follow a dot in a symbol name with something other than one of
2231 the four characters 'B', 'W', 'S' or 'L'.
2233 **addressing mode syntax**
2235 You made a syntax error in an addressing mode.
2239 One of your **.assert** directives failed!
2241 **bad (section) expression**
2243 You tried to mix and match sections in an expression.
2245 **bad 6502 addressing mode**
2247 The 6502 mnemonic will not work with the addressing mode you specified.
2251 There's a syntax error in the expression you typed.
2253 **bad size specified**
2255 You tried to use an inappropriate size suffix for the instruction. Check your
2256 68000 manual for allowable sizes.
2260 You can't use .b (byte) mode with the **movem** instruction.
2262 **cannot .globl local symbol**
2264 You tried to make a confined symbol global or common.
2266 **cannot initialize non-storage (BSS) section**
2268 You tried to generate instructions (or data, with dc) in the BSS or ABS section.
2270 **cannot use '.b' with an address register**
2272 You tried to use a byte-size suffix with an address register. The 68000 does not
2273 perform byte-sized address register operations.
2275 **directive illegal in .6502 section**
2277 You tried to use a 68000-oriented directive in the 6502 section.
2281 The expression you typed involves a division by zero.
2283 **expression out of range**
2285 The expression you typed is out of range for its application.
2287 **external byte reference**
2289 You tried to make a byte-sized reference to an external symbol, which the
2290 object file format will not allow.
2292 **external short branch**
2294 You tried to make a short branch to an external symbol, which the linker cannot
2297 **extra (unexpected) text found after addressing mode**
2299 RMAC thought it was done processing a line, but it ran up against "extra"
2300 stuff. Be sure that any comment on the line begins with a semicolon, and check
2301 for dangling commas, etc.
2303 **forward or undefined .assert**
2305 The expression you typed after a **.assert** directive had an undefined value.
2306 Remember that RMAC is one-pass.
2308 **hit EOF without finding matching .endif**
2310 The assembler fell off the end of last input file without finding a **.endif** to
2311 match an . it. You probably forgot a **.endif** somewhere.
2313 **illegal 6502 addressing mode**
2315 The 6502 instruction you typed doesn't work with the addressing mode you
2318 **illegal absolute expression**
2320 You can't use an absolute-valued expression here.
2322 **illegal bra.s with zero offset**
2324 You can't do a short branch to the very next instruction (read your 68000
2327 **illegal byte-sized relative reference**
2329 The object file format does not permit bytes contain relocatable values; you
2330 tried to use a byte-sized relocatable expression in an immediate addressing
2333 **illegal character**
2335 Your source file contains a character that RMAC doesn't allow. (most
2336 control characters fall into this category).
2338 **illegal initialization of section**
2340 You tried to use .dc or .dcb in the BSS or ABS sections.
2342 **illegal relative address**
2344 The relative address you specified is illegal because it belongs to a different
2347 **illegal word relocatable (in .PRG mode)**
2349 You can't have anything other than long relocatable values when you're gener-
2350 ating a **.PRG** file.
2352 **inappropriate addressing mode**
2354 The mnemonic you typed doesn't work with the addressing modes you specified.
2355 Check your 68000 manual for allowable combinations.
2357 **invalid addressing mode**
2359 The combination of addressing modes you picked for the **movem** instruction
2360 are not implemented by the 68000. Check your 68000 reference manual for
2363 **invalid symbol following ^^**
2365 What followed the ^^ wasn't a valid symbol at all.
2367 **mis-nested .endr**
2369 The assembler found a **.endr** directive when it wasn't prepared to find one.
2370 Check your repeat-block nesting.
2372 **mismatched .else**
2374 The assembler found a **.else** directive when it wasn't prepared to find one.
2375 Check your conditional assembly nesting.
2377 **mismatched .endif**
2379 The assembler found a **.endif** directive when it wasn't prepared to find one.
2380 Check your conditional assembly nesting.
2386 **missing argument name**
2388 **missing close parenthesis ')'**
2390 **missing close parenthesis ']'**
2394 **missing filename**
2400 **missing symbol or string**
2402 The assembler expected to see a symbol/filename/string (etc...), but found
2403 something else instead. In most cases the problem should be obvious.
2405 **misuse of '.', not allowed in symbols**
2407 You tried to use a dot (.) in the middle of a symbol name.
2411 The expression you typed involves a modulo by zero.
2413 **multiple formal argument definition**
2415 The list of formal parameter names you supplied for a macro definition includes
2416 two identical names.
2418 **multiple macro definition**
2420 You tried to define a macro which already had a definition.
2422 **non-absolute byte reference**
2424 You tried to make a byte reference to a relocatable value, which the object file
2425 format does not allow.
2427 **non-absolute byte value**
2429 You tried to dc.b or dcb.b a relocatable value. Byte relocatable values are
2430 not permitted by the object file format.
2432 **register list order**
2434 You tried to specify a register list like **D7-D0**, which is illegal. Remember
2435 that the first register number must be less than or equal to the second register
2438 **register list syntax**
2440 You made an error in specifying a register list for a **.reg** directive or a **.movem**
2443 **symbol list syntax**
2445 You probably forgot a comma between the names of two symbols in a symbol
2446 list, or you left a comma dangling on the end of the line.
2450 This is a "catch-all" error.
2452 **undefined expression**
2454 The expression has an undefined value because of a forward reference, or an
2455 undefined or external symbol.
2457 **unimplemented directive**
2459 You have found a directive that didn't appear in the documentation. It doesn't
2462 **unimplemented mnemonic**
2466 **unknown symbol following ^^**
2468 You followed a ^^ with something other than one of the names defined, referenced
2471 **unterminated string**
2473 You specified a string starting with a single or double quote, but forgot to type
2478 The assembler had a problem writing an object file. This is usually caused by
2479 a full disk, or a bad sector on the media.