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<H3>Overview of zmac</H3> zmac is a Z-80 macro cross-assembler. It has all the features you'd expect. It assembles the specified input file (with a '.z' extension if there is no pre-existing extension and the file as given doesn't exist) and produces program output in many different <A HREF="#format">formats</A>. It also produces a nicely-formatted listing of the machine code and cycle counts alongside the source in a ".lst" file. <P> To reduce clutter and command line option usage, by default all zmac output is put into an (auto-created) <TT>zout</TT> subdirectory. For <TT>file.z</TT> the listing will be in <TT>zout/file.lst</TT>, the TRS-80 executable format in <TT>zout/file.cmd</TT> and so on. For more friendly usage in make files and integrated development environments the <TT>-o</TT>, <TT>--oo</TT>, <TT>--xo</TT> and <TT>--xd</TT> options may be used to select sepcific output file formats and where they are written. <P> <A HREF="#undoc">Undocumented</A> Z-80 instructions are supported as well as 8080 code. <P> zmac strives to be a powerful assembler with expressions familiar to C programmers while providing good backward compatibility with original assemblers such as Edtasm, MRAS and Macro-80. <HR> <H3>Usage</H3> zmac [ --help ] [ --version ] [ --dep ] [ --mras ] [ --od dir ] [ --oo sfx1,sfx2 ] [ --xo sfx1,sfx2 ] [ --rel ] [ --rel7 ] [ --doc ] [ --zmac ] [ -8bcefghijJlLmnopstz ] [ filename[.z] ] <P> <H3>Options</H3> <P> <TABLE> <TR><TD VALIGN="TOP"><PRE>--help </PRE></TD><TD>Display a list of options and a terse description of what the options do. </TD></TR> <TR><TD VALIGN="TOP"><PRE>--version </PRE></TD><TD>Print zmac version name. </TD></TR> <TR><TD VALIGN="TOP"><PRE>--mras </PRE></TD><TD>MRAS compatibility mode. Any <TT>?</TT> in a label will be expanded to the current module identifier as set by <TT>*mod</TT>. Operator <A HREF="#mrasord">precedence</A> and results are changed. </TD></TR> <TR><TD VALIGN="TOP"><PRE>--od dir </PRE></TD><TD>Place output files in <TT>dir</TT> instead of the default "zout" subdirectory. Creates <TT>dir</TT> if necessary. </TD></TR> <TR><TD VALIGN="TOP"><PRE>--oo hex,cmd </PRE></TD><TD>Output only the the file types by suffix. Multiple --oo arguments may be used. "--oo lst,cas" is equivalent to "--oo lst --oo cas". See "Output Formats" for a list of output types by <A HREF="#format">suffix</A>. </TD></TR> <TR><TD VALIGN="TOP"><PRE>--xo tap,wav </PRE></TD><TD>Do not output the file type types listed by suffix. </TD></TR> <TR><TD VALIGN="TOP"><PRE>--rel </PRE></TD><TD>Output ".rel" (relocatable object file) format only. Exported symbols are truncated to length 6. </TD></TR> <TR><TD VALIGN="TOP"><PRE>--rel7 </PRE></TD><TD>Output ".rel" (relocatable object file) format only. Exported symbols are truncated to length 7. </TD></TR> <TR><TD VALIGN="TOP"><PRE>--zmac </PRE></TD><TD>zmac compatibility mode. <TT>defl</TT> labels are undefined after each pass. Quotes and double quotes are stripped from macro arguments before expansion. <TT>$</TT> is ignored in identifiers allowing <TT>foo$bar</TT> to construct identifiers in macro expansions. Use <TT>`</TT> (backquote) instead in normal mode. Labels starting with <TT>"."</TT> are temporary and are reset whenever a non-temporary label is defined (thus they may be reused). Labels starting with <TT>"_"</TT> are local to their file thus avoid multiple definition when brought in with <TT>include</TT>. </TD></TR> <TR><TD VALIGN="TOP"><PRE>--dep </PRE></TD><TD>Print all files read by <TT>include</TT>, <TT>incbin</TT> and <TT>import</TT>. </TD></TR> <TR><TD VALIGN="TOP"><PRE>--doc </PRE></TD><TD>Print this documentation in HTML format to standard output. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-Pk=number </PRE></TD><TD>Set <TT>@@k</TT> to the given numeric value before assembly. Up to 10 parameters can be set from 0 though 9. <TT>-Pk</TT> is shorthand for <TT>-Pk=-1</TT>. For example, <TT>P4=$123</TT> effectively puts <TT>@@4 equ $123</TT> at the top of the first file. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-8 </PRE></TD><TD>Accept 8080 mnemonics preferentially and use 8080 instruction timings. Equivalent to <TT>.8080</TT> pseudo-op. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-b </PRE></TD><TD>Don't generate any machine code output at all. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-c </PRE></TD><TD>Don't display cycle counts in the listing. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-e </PRE></TD><TD>Omit the "error report" section in the listing. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-f </PRE></TD><TD>List instructions not assembled due to "<TT>if</TT>" expressions being false. (Normally these are not shown in the listing.) </TD></TR> <TR><TD VALIGN="TOP"><PRE>-g </PRE></TD><TD>List only the first line of equivalent hex for a source line. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-h </PRE></TD><TD>Display a list of options and a terse description of what the options do. (same as --help) </TD></TR> <TR><TD VALIGN="TOP"><PRE>-i </PRE></TD><TD>Don't list files included with <TT>include</TT>, <TT>read</TT> or <TT>import</TT>. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-I dir </PRE></TD><TD>Add <TT>dir</TT> to the end of the include file search path. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-j </PRE></TD><TD>Promote relative jumps and <TT>DJNZ</TT> to absolute equivalents as needed. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-J </PRE></TD><TD>Error if an absolute jump could be replaced with a relative jump. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-l </PRE></TD><TD>List to standard output. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-L </PRE></TD><TD>Generate listing no matter what. Overrides any conflicting options. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-m </PRE></TD><TD>List macro expansions. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-n </PRE></TD><TD>Omit line numbers from listing. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-o filename.cmd </PRE></TD><TD>Output only the named file. Multiple "-o" options can be used to name a set of different files. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-p </PRE></TD><TD>Use a few linefeeds for page break in listing rather than ^L. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-P </PRE></TD><TD>Output listing for a printer with headers, multiple symbols per column, etc. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-s </PRE></TD><TD>Omit the symbol table from the listing. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-t </PRE></TD><TD>Only output number of errors instead list of each one. </TD></TR> <TR><TD VALIGN="TOP"><PRE>-z </PRE></TD><TD>Accept Z-80 mnemonics preferentially and use Z-80 instruction timings. Equivalent to <TT>.z80</TT> pseudo-op. </TD></TR> </TABLE> <HR> <H3>Input Format</H3> <P> zmac uses the standard Zilog mnemonics, and the pseudo-ops are also largely as you'd expect. <P> A "<TT>.</TT>" may optionally preceeed any psuedo-op. For example, "<TT>.org</TT>" and "<TT>org</TT>" are treated as equivalent. <P> Input can be upper or lowercase. <P> Comments start with <TT>;</TT> and carry on to the end of the line. <P> Number constants can take a trailing h or a leading $ or 0x for hex, a trailing b for binary, a trailing o or q for octal, or a trailing d for decimal. <P> <TT>'LH'</TT> (any length 2 string) can be treated as a number whose value is <TT>'H'</TT> * 256 + <TT>'L'</TT>. <P> Labels are declared with <TT>label:</TT> or just <TT>label</TT> - indentation is unimportant. Labels can be up to 40 chars long. They can start with and contain letters, digits, <TT>$</TT>, <TT>.</TT>, <TT>?</TT>, <TT>@</TT> and _. Ambiguous identifiers like <TT>$FCB</TT> will be treated as hex constants unless defined as a label. Labels declared with two colons (<TT>label::</TT>) make the label public. <P> Single quotes are ignored at the end of identifiers allowing non-binding <A HREF="#prime">notation</A> indicating alternate register use during heavy applications of <TT>exx</TT> and <TT>ex</TT>. <P> Here is how other things work. Numbers are used as examples, but a full <A HREF="#expr">expression</A> can be used in their place. <P> <H4>Data</H4> <P> <TT>defb 42</TT> <BLOCKQUOTE>A byte. <TT>ascii</TT>, <TT>byte</TT>, <TT>db</TT>, <TT>defm</TT>, <TT>dm</TT> and <TT>text</TT> are synonyms. </BLOCKQUOTE> <P> <TT>defb 'foobar'</TT> <BLOCKQUOTE>An ASCII character string (not NUL-terminated). Double quotes can also be used. </BLOCKQUOTE> <P> <TT>defb 'Who needs anything more than CP/M?',13,10,'$'</TT> <BLOCKQUOTE>Strings and bytes can mix together. </BLOCKQUOTE> <P> <TT>defw 2112</TT> <P> <TT>defw $123,0x456</TT> <BLOCKQUOTE>A word (16 bits). <TT>word</TT> and <TT>dw</TT> are synonyms. </BLOCKQUOTE> <P> <TT>defd $12345678</TT> <BLOCKQUOTE>A double word (32 bits). <TT>dword</TT> is a synonym. </BLOCKQUOTE> <P> <TT>defs 500</TT> <BLOCKQUOTE>Skip output ahead 500 bytes. This will insert 500 zeros in the ".ams" and ".cim" output files or if inside a ".phase" section. <TT>block</TT>, <TT>ds</TT> and <TT>rmem</TT> are synonyms. </BLOCKQUOTE> <P> <TT>dc 'string'</TT> <BLOCKQUOTE>Like <TT>ascii</TT> but accepts only a single string and the high bit of the last character will be set. <TT>bytes</TT> is a synonym. </BLOCKQUOTE> <P> <TT>dc count,value</TT> <BLOCKQUOTE>Repeat the byte <TT>value</TT> a total of <TT>count</TT> times. Similar to <TT>defs</TT> except that memory is always filled with <TT>value</TT>. </BLOCKQUOTE> <P> <TT>incbin file</TT> <BLOCKQUOTE>Inserts the raw contents of the file into the assembly. Simpler for large amounts of data. </BLOCKQUOTE> <P> <H4>Symbols</H4> <P> <TT>label equ 100</TT> <BLOCKQUOTE>Define a symbol to have a fixed value. The symbol can be used before it is defined. A symbol defined with <TT>equ</TT> or as a label can be defined only once, except that a symbol defined with <TT>equ</TT> may be redefined to the same value. </BLOCKQUOTE> <P> <TT>varname defl 200</TT> <BLOCKQUOTE>Define a symbol to have a changeable value. The symbol cannot be used before it is defined, and it can be redefined to a different value later with another <TT>defl</TT>. <TT>aset</TT>, <TT>set</TT> and <TT>=</TT> are synonyms (despite <TT>set</TT> also being a Z-80 mnemonic). </BLOCKQUOTE> <P> <TT>varname OP = expression</TT> <BLOCKQUOTE>Shorthand for <TT>varname defl varname OP expression</TT>. Allows for C-like handling of variable such as <TT>var += 5</TT>. <TT>OP</TT> can be <TT>+</TT>, <TT>-</TT>, <TT>*</TT>, <TT>/</TT>, <TT>%</TT>, <TT>&</TT>, <TT>|</TT>, <TT>^</TT>, <TT><<</TT>, <TT>>></TT>, <TT>&&</TT> or <TT>||</TT>. </BLOCKQUOTE> <P> <TT>varname++</TT> <BLOCKQUOTE>Shorthand for <TT>varname defl varname + 1</TT> </BLOCKQUOTE> <P> <TT>varname--</TT> <BLOCKQUOTE>Shorthand for <TT>varname defl varname - 1</TT> </BLOCKQUOTE> <P> <TT>min</TT> <P> <TT>max</TT> <BLOCKQUOTE>Same as <TT>defl</TT> except that the symbol is defined as the smaller or bigger of two comma-separated expressions. </BLOCKQUOTE> <P> <TT>*mod</TT> <BLOCKQUOTE>Increment the internal module name string. The first time this results in "a". Then "b", "c", ... "z". Then "aa", "ab", "ac", etc. all the way up to "zzzz". The module name string is used in <TT>--mras</TT> mode where "?" in label names is replaced with the current module name. </BLOCKQUOTE> <P> <TT>extern lab1,lab2,...</TT> <BLOCKQUOTE>The listed labels are defined in an external module for later linking. No effect unless zmac is producing ".rel" output. <TT>ext</TT> and <TT>extrn</TT> are synonyms. </BLOCKQUOTE> <P> <TT>public lab1,lab2,...</TT> <BLOCKQUOTE>The given labels will be visible to external modules when linking. No effect unless zmac is producing ".rel" output. <TT>global</TT> and <TT>entry</TT> are synonyms. </BLOCKQUOTE> <P> <TT>label ++</TT> <BLOCKQUOTE>Equivalent to <TT>label defl label + 1</TT>. </BLOCKQUOTE> <P> <TT>label --</TT> <BLOCKQUOTE>Equivalent to <TT>label defl label - 1</TT>. </BLOCKQUOTE> <P> <TT>label += 10</TT> <P> <TT>label -= 10</TT> <P> <BLOCKQUOTE>Equivalent to <TT>label defl label + 10</TT> and <TT>label defl label - 10</TT> respectively. Also works for <TT>*=</TT>, <TT>/=</TT>, <TT>%=</TT>, <TT>|=</TT>, <TT>&=</TT>, <TT>^=</TT>, <TT><<=</TT> and <TT>>>=</TT>. </BLOCKQUOTE> <P> <H4>Location Control</H4> <P> <TT>org 9000h</TT> <BLOCKQUOTE>Set the address to assemble to 0x9000. </BLOCKQUOTE> <P> <TT>phase address</TT> <BLOCKQUOTE>Continue to produce code and data for loading at the current address but assemble instructions and define labels as if they originated at the given address. Useful when producing code that will be copied to a different location before being executed (e.g., an overlay). </BLOCKQUOTE> <P> <TT>dephase</TT> <BLOCKQUOTE>End <TT>phase</TT> mode assembly. </BLOCKQUOTE> <P> <TT>aseg</TT> <TT>cseg</TT> <TT>dseg</TT> <BLOCKQUOTE>Switch to the absolute, code and data segments respectively. No effect unless zmac is producing ".rel" output. </BLOCKQUOTE> <P> <TT>common /name/</TT> <BLOCKQUOTE>Set the address to the start of the selected common block. The blank common block will be selected if name is empty or all blanks or omitted entirely. No effect unless zmac is producing ".rel" output. </BLOCKQUOTE> <P> <H4>Input Control</H4> <P> <TT>end</TT> <BLOCKQUOTE>Ends the input. Any lines after an <TT>end</TT> are silently ignored. If an arg is given, it declares the entry address for the program. This has no effect in ".cim" output. In ".hex" output it generates an S-record directing 0 bytes of data to be loaded at the given address. It is required for ".500.cas", ".1000.cas" and ".1500.cas" output. </BLOCKQUOTE> <P> <TT>if</TT> ... [ <TT>else</TT> ... ] <TT>endif</TT> <BLOCKQUOTE>For conditional assembly. If you do <TT>if foo</TT> and <TT>foo</TT> evaluates to zero, all the lines up until the next corresponding <TT>else</TT> or <TT>endif</TT> are completely ignored. Conversely, if <TT>foo</TT> evaluates to non-zero, any lines from a corresponding <TT>else</TT> to the <TT>endif</TT> are ignored. Ifs can be nested. <TT>cond</TT>/<TT>endc</TT> are synonyms for <TT>if</TT>/<TT>endif</TT>. </BLOCKQUOTE> <P> <TT>ifdef symbol</TT> <BLOCKQUOTE>Like <TT>if</TT>, but tests if <TT>symbol</TT> has been defined. Declaring a symbol as external counts as it being defined. </BLOCKQUOTE> <P> <TT>ifndef symbol</TT> <BLOCKQUOTE>Like <TT>if</TT>, but tests if <TT>symbol</TT> has not yet been defined. </BLOCKQUOTE> <P> <TT>import file</TT> <BLOCKQUOTE>Like <TT>include</TT> but will only bring in the file once. File tracking is done using only the file name so, for example, an <TT>import file</TT> will stop both <TT>import ./file</TT> and <TT>import dir/file</TT> even if they actually refer to different files. </BLOCKQUOTE> <P> <TT>include file</TT> <BLOCKQUOTE>Include a file. Like C's (well, cpp's) #include and follows the same include path search rules, but the filename arg lacks the angle brackets or quotes (though single or double quotes may be used). <TT>read</TT> is a synonym. <TT>*include file</TT> also works if started in the first column. In <TT>--mras</TT> mode <TT>".asm"</TT> will be added if <TT>file</TT> has no suffix. </BLOCKQUOTE> <P> <TT>maclib file</TT> <BLOCKQUOTE>Like <TT>include</TT> but adds <TT>.lib</TT> to the file name so includes <TT>file.lib</TT>. </BLOCKQUOTE> <P> <TT>comment X</TT> <BLOCKQUOTE>Suspend assembly until the next occurence of character <TT>X</TT> on a line. The rest of the line will be ignored. A multi-line comment. </BLOCKQUOTE> <P> <TT>assert expr</TT> <BLOCKQUOTE>Stop assembly if <TT>expr</TT> is non-zero. </BLOCKQUOTE> <P> <H4>Cycle Counting</H4> <P> <TT>sett expr</TT> <BLOCKQUOTE>Set the current T-state count to <TT>expr</TT>. <TT>tstate</TT> is a synonym. </BLOCKQUOTE> <P> <TT>setocf expr</TT> <BLOCKQUOTE>Set the current opcode fetch count to <TT>expr</TT>. </BLOCKQUOTE> <P> <H4>Code Generation</H4> <P> <TT>8080</TT> <BLOCKQUOTE>Make cycle counting operators return 8080 cycle counts and interpret any ambiguous assembly statements as Intel 8080 mnemonics. <TT>CP</TT> will be interpreted as "call on positive" and <TT>JP</TT> as "jump on positive". </BLOCKQUOTE> <P> <TT>z80</TT> <BLOCKQUOTE>Make cycle counting operators return Z-80 cycle counts and interpret any ambiguous assembly statements as Zilog Z-80 mnemonics. <TT>CP</TT> will be interpreted as "compare accumulator" and <TT>JP</TT> as "jump unconditionally". </BLOCKQUOTE> <P> <TT>jperror enable</TT> <BLOCKQUOTE>If <TT>enable</TT> is non-zero, turn on errors when <TT>JR</TT> instructions could be used instead of <TT>JP</TT>, off otherwise. Used to check existing code for situations where shorter code could be generated. Same as <TT>-J</TT> option. No effect if in 8080 mode. </BLOCKQUOTE> <P> <TT>jrpromote enable</TT> <BLOCKQUOTE>If <TT>enable</TT> is non-zero, <TT>JR</TT> and <TT>DJNZ</TT> instructions will be promoted to equivalent <TT>JP</TT> and <TT>DEC B</TT>, <TT>JP NZ</TT> instructions if the relative branch offset is out of range. If <TT>enable</TT> is zero, promotion is disabled. Same as the <TT>-j</TT> option. No effect if in 8080 mode. </BLOCKQUOTE> <P> <H4>Undocumented <A NAME="undoc">Instructions</A></H4> <P> Most Z-80 chips support a number of undocumented instructions that were part of the original design but not made an offical part of the Zilog specification. These instructions may not be supported by all Z-80 chips, especially licensed variants, but are fairly widely available nonetheless. <P> <TT>sl1 r</TT> <BLOCKQUOTE>Same as <TT>sla r</TT> but shifts a 1 into the lower bit of <TT>r</TT> rather than a 0. </BLOCKQUOTE> <P> <TT>in (c)</TT> <BLOCKQUOTE>Inputs a byte from port <TT>c</TT> but does not store the value. Flags are still set as with the normal <TT>in r,(c)</TT> instruction. </BLOCKQUOTE> <P> <TT>out (c),0</TT> <BLOCKQUOTE>Outputs a zero to port <TT>c</TT>. </BLOCKQUOTE> <P> <TT>bit/set/res n,(ix+d),r</TT> <P> <TT>rlc/rrc/rl/rr/sla/sl1/sra/srl (iy+d),r</TT> <BLOCKQUOTE>Same as the corresponding operation on just <TT>(ix+d)</TT> or <TT>(iy+d)</TT> but with the result being stored both into <TT>(ix+d)</TT> and register <TT>r</TT>. Except for <TT>bit</TT> which has no effect on <TT>r</TT>. zmac supports the syntax to allow those instruction patterns to be generated. </BLOCKQUOTE> <P> The upper and lower bytes of the <TT>ix</TT> and <TT>iy</TT> can be used in a number of instructions much in the same way as <TT>d</TT> and <TT>e</TT> correspond to the upper and lower bytes of <TT>de</TT>. zmac names these <TT>ixh</TT>, <TT>ixl</TT>, <TT>iyh</TT> and <TT>iyl</TT> and are referred to generically as <TT>ixylh</TT> here. <P> <TT>inc/dec/add/adc/sub/sbc/and/xor/or/cp ixylh</TT> <BLOCKQUOTE>Arithmetic or logical operation on <TT>ix</TT> or <TT>iy</TT> high or low byte. </BLOCKQUOTE> <P> <TT>ld a/b/c/d/e,ixylh</TT> <BLOCKQUOTE>Load register with <TT>ix</TT> or <TT>iy</TT> high or low byte. </BLOCKQUOTE> <P> <TT>ld ixylh,a/b/c/d/e</TT> <BLOCKQUOTE>Load <TT>ix</TT> or <TT>iy</TT> high or low byte with register. </BLOCKQUOTE> <P> <TT>pfix</TT> <P> <TT>pfiy</TT> <BLOCKQUOTE>Output $DD and $FD prefix bytes. The Z-80 allows multiple prefix bytes for IX and IY instructions. This allows you to specify them abstractly. There is little purpose except for delaying an interrupt or confusing disassemblers. </BLOCKQUOTE> <P> <H4>Miscellaneous</H4> <P> <TT>pragma str ...</TT> <BLOCKQUOTE>Like C's #pragma, a generic hook for special purpose operations. Only two are currently defined. </BLOCKQUOTE> <P> <BLOCKQUOTE><TT>pragma bds rest-of-line</TT> to output <TT>rest-of-line</TT> to the <TT>.bds</TT> output file. </BLOCKQUOTE> <P> <BLOCKQUOTE><TT>pragma mds rest-of-line</TT> to output <TT>rest-of-line</TT> to the <TT>.mds</TT> output file. </BLOCKQUOTE> <P> <BLOCKQUOTE>The <TT>.bds</TT> output format supports setting initial values for Z-80 registers and I/O ports so <TT>pragma</TT> gives you access to that. </BLOCKQUOTE> <P> <BLOCKQUOTE>The <TT>.mds</TT> output format is a MAME debug script thus additional initial debugging commands may be output. Of particular use on the TRS-80 Model II is <TT>pragma mds ib@$ff=1</TT> which maps page 1 of RAM into $8000 .. $FFFF and thus allows programs to load into that area. </BLOCKQUOTE> <P> <TT>name str</TT> <BLOCKQUOTE>Set the name of the output module to <TT>str</TT>. For compatibility reasons <TT>str</TT> may be parenthesized (e.g., "<TT>name ('foo')</TT>"). Not all output formats support an internal name and many have severe length limits. </BLOCKQUOTE> <P> <TT>rsym</TT> and <TT>wsym</TT> <BLOCKQUOTE>Read/write a symbol file. These simply load/save the currently defined symbols from/to the file specified (in a non-portable format). <TT>rsym</TT> takes place at the point it is encountered in the file (on the first pass); <TT>wsym</TT> is delayed until assembly has finished. </BLOCKQUOTE> <P> <H4>Listing Pseudo-ops</H4> <P> There are several pseudo-ops for controlling the listing. None of these ops appear in the listing themselves: <P> <TT>eject</TT> <BLOCKQUOTE>Start a new listing page. </BLOCKQUOTE> <P> <TT>nolist</TT> <BLOCKQUOTE>Do nothing. This can be used to have a comment in the source but not the listing, I suppose. </BLOCKQUOTE> <P> <TT>elist</TT>, <TT>flist</TT>, <TT>glist</TT>, <TT>mlist</TT> <BLOCKQUOTE>These have the same effect as the similarly-named command-line options, though possibly with the sense reversed depending on the default. Use an arg >0 (or no arg) to enable, and an arg <0 to disable. </BLOCKQUOTE> <P> <TT>list arg</TT> <BLOCKQUOTE>Turns output to listing file (.list) off if <TT>arg</TT> < 0 or on if <TT>arg</TT> > 0. If no <TT>arg</TT> supplied then listing is enabled. Use this to avoid listing certain parts of the source. In <TT>--mras</TT> mode <TT>arg</TT> must be either <TT>on</TT> or <TT>off</TT> and <TT>*list</TT> can be used if started in the first column. </BLOCKQUOTE> <P> <TT>title</TT> <BLOCKQUOTE>Set title (used in listing and symbol file). </BLOCKQUOTE> <P> <TT>space arg</TT> <BLOCKQUOTE>Output arg blank lines in the listing, or one line if no arg is given. </BLOCKQUOTE> <P> <HR> <P> <H3><A NAME="expr">Expressions</A></H3> <P> Expressions feature a full set of C operators with the same precedence rules and some common assembler extensions and names. Here is the complete list of operators, highest-precedence first. Operators separated only by a space are synonyms; for example, <TT>~</TT> is the same as <TT>not</TT>. <P> <TT>!</TT> (logical), <TT>~ not</TT> (bitwise), <TT>+</TT> (unary), <TT>-</TT> (unary), <TT>low</TT>, <TT>high</TT>, <TT>t</TT>, <TT>tilo</TT>, <TT>tihi</TT>, <TT>ocf</TT> <P> <TT>*</TT>, <TT>/</TT>, <TT>% mod</TT> <P> <TT>+</TT>, <TT>-</TT> <P> <TT><< shl</TT>, <TT>>> shr</TT> <P> <TT>< lt</TT>, <TT>> gt</TT>, <TT><= le</TT>, <TT>>= ge</TT> <P> <TT>== = eq</TT>, <TT>!= <> ne</TT> <P> <TT>& and</TT> (bitwise) <P> <TT>^ xor</TT> (bitwise) <P> <TT>| or</TT> (bitwise) <P> <TT>&&</TT> <P> <TT>||</TT> <P> <TT>? :</TT> (ternary choice operator) <P> <A NAME="mrasord">Expressions</A> change significantly in <TT>--mras</TT> mode: <BLOCKQUOTE>Evaluation is strictly left to right. Except for <TT>and</TT>, <TT>or</TT>, <TT>xor</TT> and <TT>=</TT>. This doesn't break compatibility as original MRAS source code only allows <TT>.and.</TT>, <TT>.or.</TT> and <TT>.xor.</TT> but the precedence difference may surprise if code is added. </BLOCKQUOTE> <P> <BLOCKQUOTE><TT>!</TT> is bitwise OR instead of logical not. </BLOCKQUOTE> <P> <BLOCKQUOTE><TT><</TT> is left shift (or right shift when shift amount is negative) </BLOCKQUOTE> <P> <BLOCKQUOTE>MRAS operators (<TT>.and.</TT> <TT>.eq.</TT> <TT>.ge.</TT> <TT>.gt.</TT> <TT>.high.</TT> <TT>.le.</TT> <TT>.low.</TT> <TT>.lt.</TT> <TT>.mod.</TT> <TT>.ne.</TT> <TT>.not.</TT> <TT>.or.</TT> <TT>.shl.</TT> <TT>.shr.</TT> <TT>.xor.</TT>) are recognized even if apparently in identifers. (e.g., <TT>a.or.b</TT> is seen as <TT>a .or. </TT>b). </BLOCKQUOTE> <P> <BLOCKQUOTE>Logical operators return -1 for true and 0 for false. Normally zmac, like C, uses 1 for true. </BLOCKQUOTE> <P> You can use normal parentheses or square brackets to override the precedence rules. Square brackets can be used where parentheses would conflict with Z-80 mnemonic syntax, but this is not necessary in any practical case. <P> The <TT>?</TT> may need spaces around it to distinguish it from a label that has <TT>?</TT> in it. <P> The unary operators not familiar to C programmers: <P> <TABLE> <TR><TD VALIGN="TOP"><PRE>low expr </PRE></TD><TD>Returns low 8 bits of <TT>expr</TT> </TD></TR> <TR><TD VALIGN="TOP"><PRE>high expr </PRE></TD><TD>Returns high 8 bits of <TT>expr</TT> </TD></TR> <TR><TD VALIGN="TOP"><PRE>t expr </PRE></TD><TD>Current count of T-states up to memory location <TT>expr</TT> </TD></TR> <TR><TD VALIGN="TOP"><PRE>tilo expr </PRE></TD><TD>Low count of T-states used by instruction at memory location <TT>expr</TT> </TD></TR> <TR><TD VALIGN="TOP"><PRE>tihi expr </PRE></TD><TD>High count of T-states used by instruction at memory location <TT>expr</TT> </TD></TR> <TR><TD VALIGN="TOP"><PRE>ocf expr </PRE></TD><TD>Current count of opcode fetches up to memory location <TT>expr</TT> </TD></TR> </TABLE> <HR> <H3>Macros</H3> The following defines a macro named m with zero or more formal parameters <TT>p1</TT>, <TT>p2</TT>, ..., <TT>pn</TT>, zero or more local symbols <TT>?s1</TT>, <TT>?s2</TT>, ..., <TT>?sm</TT>, and body <TT>b1</TT>, <TT>b2</TT>, ...: <P> <TABLE> <TR><TD VALIGN="TOP"><PRE><TT>m macro p1, p2, ..., pn, ?s1, ?s2, ..., ?sm</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT> b1</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT> b2</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT> ...</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT> endm</TT> </TD></TR> </TABLE> <P> The macro is called by writing: <BLOCKQUOTE><TT>m v1, v2, ..., vn</TT> </BLOCKQUOTE> <P> A macro call expands to the text of the macro's body, with each occurrence of a formal parameter <TT>pk</TT> replaced by the corresponding value <TT>vk</TT>, and with each local symbol <TT>?sk</TT> replaced by a new, unique symbol invented for this call. Invented symbols begin with <TT>?</TT>, so you should avoid using such symbols elsewhere in your program. <P> zmac currently does not check that you have provided the right number of parameters when calling a macro. If you provide too few, unmatched formals are replaced with the empty string. If you provide too many, the additional values begin to replace local symbols as if they were ordinary parameters. (This could be considered a feature.) After the local symbols are all replaced, additional parameters are silently ignored. <P> For compatibility with Macro-80, the first line of a macro definition can list other labels that will be treated locally: <P> <BLOCKQUOTE><TT> local lab1,lab2,...</TT> </BLOCKQUOTE> <P> Each time the macro is expanded the local labels are replaced with unique names thus avoiding multiple definition problems. <P> For compatability with MRAS, macro arguments may be preceeded by <TT>#</TT> in their definition and use. <P> Any <TT>`</TT> (backquote) in a macro is ignored thus allowing a macro to construct identifiers. For example: <P> <TABLE> <TR><TD VALIGN="TOP"><PRE><TT>move macro dir</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT> ld`dir`r</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT> endm</TT> </TD></TR> </TABLE> <P> Invoking <TT>move i</TT> will construct a <TT>ldir</TT> block move instruction. <P> For compatibility, <TT>&</TT> can also be used as in MAC to concatenate macro parameters. This conflicts with zmac's bitwise and operator but you can use the <TT>and</TT> synonym in macros to avoid the conflict. <P> In <TT>--mras</TT> mode arguments will be expanded even if they are inside other identifiers. The <TT>move</TT> could be written: <P> <TABLE> <TR><TD VALIGN="TOP"><PRE><TT>move macro dir</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT> lddirr</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT> endm</TT> </TD></TR> </TABLE> <P> Macro definitions can contain macro definitions which will be defined when the outer macro is first exapnded. Macros can be redefined as well. <P> Macro expansion continues to the <TT>endm</TT> directive but can be stopped prematurely by the <TT>exitm</TT> directive. Typically the <TT>exitm</TT> is inside some conditional part of the macro. <P> Parameters passed to a macro can be empty and are tested with the <TT>nul</TT> operator: <P> <TABLE> <TR><TD VALIGN="TOP"><PRE><TT>if nul &par</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT>...</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT>endif</TT> </TD></TR> </TABLE> <P> Macro parameters can contain commas if grouped inside <TT><</TT> and <TT>></TT>. Or a comma can be escaped with <TT>^</TT> which can also escape spaces and other special characters. It is also be put in front of a macro parameter name inside the expansion to suppress the replacement by its value. <P> Expansion of parameters in a macro body is purely textual. This can lead to surprises in complex situations. The <TT>%</TT> character can be used to force a macro parameter to be replaced with the evaluation of it as an expression. <P> <P> <H4>Inline Macros</H4> <P> zmac supports the commonly available <TT>rept</TT>, <TT>irp</TT> and <TT>irpc</TT> inline macros <P> <TT>rept</TT> repeats its block the given number of times. This will output 10 <TT>nop</TT> instructions: <P> <TABLE> <TR><TD VALIGN="TOP"><PRE><TT>rept 10</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT> nop</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT>endm</TT> </TD></TR> </TABLE> <P> <TT>irpc</TT> runs through a string of letters assigned them to a variable and expanding the macro block each time. For example, this will load 7 into registers <TT>b</TT>, <TT>d</TT> and <TT>h</TT>: <P> <TABLE> <TR><TD VALIGN="TOP"><PRE><TT>irpc reg,bdh</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT> ld &reg,7</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT>endm</TT> </TD></TR> </TABLE> <P> <TT>irp</TT> runs through a list of parameters assiging each entry to a variable and expanding the macro block. Here we load <TT>bc</TT>, <TT>de</TT> and <TT>hl</TT> with 0: <P> <TABLE> <TR><TD VALIGN="TOP"><PRE><TT>irp rpair,<bc,de,hl></TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT> ld &rpair,0</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT>endm</TT> </TD></TR> </TABLE> <P> Lists can be nested. Here's an example of and <TT>irp</TT> passing lists on down to another <TT>irp</TT>: <P> <TABLE> <TR><TD VALIGN="TOP"><PRE><TT>irp listlist,<<one,two,three>,<four,five,six>></TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT>irp list,<listlist></TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT>ascii '&list'</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT>endm</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT>endm</TT> </TD></TR> </TABLE> <P> <P> <HR> <H3>Compatibility</H3> <P> zmac is broadly compatible with many original Z-80 and 8080 assemblers because it accepts many different names for common operations and has liberal identifier and numeric formats. It also accepts most simple usage of macros. <P> When assembling old code keep these portability problems in mind. <P> Expression order of evaluation may be different. zmac uses C semantics more order of evaluation but assemblers often used simple left to right ordering. zmac will evaluate <TT>2+2*3</TT> as <TT>8</TT> where other assemblers will yield <TT>12</TT>. However, in <TT>--mras</TT> mode expressions are evaluated strictly left-to-right for compatibility. <P> zmac has no support operating on strings in macros. Assemblers like Macro-80 could perform conditional tests on strings. <P> Advanced macros are unlikely to work. zmac hasn't advanced to the state where all the possible ways of substituting parameters are supported. <P> Consult the original assembler manual. zmac error messages won't help you figure out what an unknown assembler command is supposed to do. <P> Compare against original output. The very safest thing to do when porting assembly code is to compare the binary output of zmac against that produced by the original assembler. This way you can ensure everything has been interpreted correctly. Only once that has been achieved should you modify the code. <HR> <H3>Errors and Warnings</H3> <P> Any errors or warnings encountered during assembly are reported to standard error and in the listing file. The errors output immediately give the source file and line number containing the error. In listings the error letter and message appear just after the line containing the error. <P> <TABLE> <TR><TD VALIGN="TOP"><PRE>B </PRE></TD><TD>Balance error </TD></TR> <TR><TD VALIGN="TOP"><PRE> </PRE></TD><TD>A string is missing an closing quote or an <TT>if</TT> is missing an <TT>endif</TT> </TD></TR> <TR><TD VALIGN="TOP"><PRE>E </PRE></TD><TD>Expression error </TD></TR> <TR><TD VALIGN="TOP"><PRE> </PRE></TD><TD>An expression did not parse or attempts a divide or modulus by 0. </TD></TR> <TR><TD VALIGN="TOP"><PRE>F </PRE></TD><TD>Syntax error </TD></TR> <TR><TD VALIGN="TOP"><PRE> </PRE></TD><TD>General problem with the syntax on a line. Sometimes extra explanation will be printed on standard output. </TD></TR> <TR><TD VALIGN="TOP"><PRE>I </PRE></TD><TD>Digit error </TD></TR> <TR><TD VALIGN="TOP"><PRE> </PRE></TD><TD>A numeric constant has too many digits to be represented as a 32 bit number. </TD></TR> <TR><TD VALIGN="TOP"><PRE>M </PRE></TD><TD>Mult. def. error </TD></TR> <TR><TD VALIGN="TOP"><PRE> </PRE></TD><TD>A symbol has been defined more than once and those values differ. </TD></TR> <TR><TD VALIGN="TOP"><PRE>P </PRE></TD><TD>Phase error </TD></TR> <TR><TD VALIGN="TOP"><PRE> </PRE></TD><TD>On the second or subsequent assembly passes the assembly has changed significantly. Most commonly it means an <TT>if</TT> has changed conditions but can also happen when labels or equated values do not converge to a fixed value. </TD></TR> <TR><TD VALIGN="TOP"><PRE>U </PRE></TD><TD>Undeclared error </TD></TR> <TR><TD VALIGN="TOP"><PRE> </PRE></TD><TD>An undeclared symbol was used in an expression or <TT>public</TT> statement. </TD></TR> <TR><TD VALIGN="TOP"><PRE>V </PRE></TD><TD>Value error </TD></TR> <TR><TD VALIGN="TOP"><PRE> </PRE></TD><TD>An invalid value was given to a statement. Often this means using less than -128 or greater then 255 in a <TT>defb</TT> or less than -32768 or greater than 65535 in a <TT>defw</TT>. Or similar invalid values used Z-80/8080 opcodes requiring an 8 or 16 bit value (and other restrictions like 0 to 7 for <TT>BIT</TT>). Also if a relative jump is out of range or if a negative value is given in <TT>defs</TT> or <TT>dc</TT>. </TD></TR> <TR><TD VALIGN="TOP"><PRE>O </PRE></TD><TD>Phase/Dephase error </TD></TR> <TR><TD VALIGN="TOP"><PRE> </PRE></TD><TD><TT>phase</TT> was used within another <TT>phase</TT> or <TT>dephase</TT> without <TT>phase</TT>. Or if <TT>org</TT> is used within <TT>phase</TT>. </TD></TR> <TR><TD VALIGN="TOP"><PRE>A </PRE></TD><TD>Assertion failure error </TD></TR> <TR><TD VALIGN="TOP"><PRE> </PRE></TD><TD>An assert statement evaluated to zero. </TD></TR> <TR><TD VALIGN="TOP"><PRE>J </PRE></TD><TD>Use JR error </TD></TR> <TR><TD VALIGN="TOP"><PRE> </PRE></TD><TD>An absolute jump instruction was used where relative jump was in range of the destination address. Only generated if <TT>-j</TT> or <TT>jrpromote</TT> is in effect. </TD></TR> <TR><TD VALIGN="TOP"><PRE>R </PRE></TD><TD>Not relocatable error </TD></TR> <TR><TD VALIGN="TOP"><PRE> </PRE></TD><TD>An expression was used that must be generated at link time but cannot be handled by the ".rel" format. For instance, an <TT>org</TT> to a symbol in the data segment when in the code segment. Or a relative jump to a different segment. The ".rel" format can evaluate expressions at link time using the <TT>high</TT>, <TT>low</TT>, <TT>not</TT>, <TT>-</TT>, <TT>+</TT>, <TT>*</TT>, <TT>/</TT> and <TT>%</TT> operators. zmac is clever enough to use <TT>high</TT> or <TT>low</TT> in place of <TT>& $ff00</TT> and <TT>& 255</TT>. But it won't replace a <TT>shl</TT> with a multiply. </TD></TR> <TR><TD VALIGN="TOP"><PRE>G </PRE></TD><TD>Register usage error </TD></TR> <TR><TD VALIGN="TOP"><PRE> </PRE></TD><TD>A invalid register was given to an instruction. For example, <TT>LD B,(DE)</TT> or <TT>ADD HL,IX</TT>. </TD></TR> <TR><TD VALIGN="TOP"><PRE>Z </PRE></TD><TD>Z-80 instruction in 8080 mode error </TD></TR> <TR><TD VALIGN="TOP"><PRE> </PRE></TD><TD>An instruction was assembled that is only valid on the Z-80 but <TT>.8080</TT> (or <TT>-8</TT>) mode is in effect. However, use use of Z-80 mnemonics that output valid 8080 instructions is always OK. </TD></TR> <TR><TD VALIGN="TOP"><PRE>H </PRE></TD><TD>$hex constant interpreted as symbol warning </TD></TR> <TR><TD VALIGN="TOP"><PRE> </PRE></TD><TD>A symbol such as <TT>$FCB</TT> has been defined even though it could appear to be a hexadecimal constant. zmac will treat <TT>$FCB</TT> as symbol for the entire assembly which could be rather surprising if that were not the intent. </TD></TR> <TR><TD VALIGN="TOP"><PRE>N </PRE></TD><TD>Not implemented warning </TD></TR> <TR><TD VALIGN="TOP"><PRE> </PRE></TD><TD>For statements that have been added as parse rules but have no effect. The only current example is <TT>subttl</TT> which sets the sub title of a listing in certain assemblers. </TD></TR> </TABLE> <P> <HR> <H3>Output <A NAME="format">Formats</A></H3> <P> Except for ".rel", zmac writes every known output when assembling by default. This is no burden on modern computers and saves having to meticulously select the desired output format. <P> ".rel" is a special case since that format is intended for linking and can have undefined external symbols which would be errors in the other formats. Conversely, a simple "org $8000" will be an error for ".rel" output as it defaults to the code segment where absolute origin statements are forbidden. <P> If ".rel" is selected for output either by <TT>--relopt</TT> or with <TT>--oo rel</TT> or <TT>-o file.rel</TT> then all other output formats are suppressed (except the ".lst" source file listing). <P> <TABLE> <TR><TD VALIGN="TOP"><PRE>.ams </PRE></TD><TD>AMSDOS executable format for Amstrad computers. </TD></TR> <TR><TD VALIGN="TOP"><PRE>.bds </PRE></TD><TD>For source-level debugging in <A HREF="http://www.48k.ca/trs80gp.html">trs80gp</A> </TD></TR> <TR><TD VALIGN="TOP"><PRE>.1500.cas </PRE></TD><TD>TRS-80 high-speed (1500 baud) cassette SYSTEM file. The internal name of the file is the source file name shortened to 6 characters with suffixes removed. Requires an entry address. </TD></TR> <TR><TD VALIGN="TOP"><PRE>.250.cas </PRE></TD><TD>TRS-80 250 baud cassette Level I CLOAD file. If your program has an entry address and $41FE does not contain that entry address then the file will be loaded at $41FE with relocation code added to move it to the desired location. </TD></TR> <TR><TD VALIGN="TOP"><PRE>.500.cas </PRE></TD><TD>TRS-80 low-speed (500 baud) cassette SYSTEM file. The internal name of the file is the source file name shortened to 6 characters with suffixes removed. Requires an entry address. </TD></TR> <TR><TD VALIGN="TOP"><PRE>.1000.cas </PRE></TD><TD>Identical to 500 baud but intended for double-speed LNW-80 which can can load cassette files at double speed for an effective 1000 baud rate. Requires an entry address. </TD></TR> <TR><TD VALIGN="TOP"><PRE>.cim </PRE></TD><TD>Core In-Memory image. A raw binary format with the first byte corresponding to the lowest generated code or data and proceeding contiguously until the highest address generated. Any gaps are filled with zeros. Typically used for CP/M where all executables start at address 256 or for ROM images. </TD></TR> <TR><TD VALIGN="TOP"><PRE>.cmd </PRE></TD><TD>TRS-80 DOS executable file format as used by all major DOSes on the TRS-80 (TRS-DOS, LDOS, MULTIDOS, NEWDOS, etc.) </TD></TR> <TR><TD VALIGN="TOP"><PRE>.hex </PRE></TD><TD>Intel hex record format. </TD></TR> <TR><TD VALIGN="TOP"><PRE>.rel </PRE></TD><TD>Relocatable object module format as produced by MACRO-80 and other assemblers. </TD></TR> <TR><TD VALIGN="TOP"><PRE>.tap </PRE></TD><TD>ZX Spectrum cassette tape format. </TD></TR> <TR><TD VALIGN="TOP"><PRE>.1500.wav </PRE></TD><TD>Same as .1500.cas but in ready-to-play audio format. </TD></TR> <TR><TD VALIGN="TOP"><PRE>.250.wav </PRE></TD><TD>Same as .250.cas but in ready-to-play audio format. </TD></TR> <TR><TD VALIGN="TOP"><PRE>.500.wav </PRE></TD><TD>Same as .500.cas but in ready-to-play audio format. </TD></TR> <TR><TD VALIGN="TOP"><PRE>.1000.wav </PRE></TD><TD>Same as .1000.cas but in ready-to-play audio format. </TD></TR> <TR><TD VALIGN="TOP"><PRE>.mds </PRE></TD><TD>MAME debug script (e.g., mame trs80 -d -debugscript zout/prog.mds) </TD></TR> </TABLE> <P> <HR> <H3>Miscellaneous</H3> In the symbol table listing, the <TT>=</TT> prefix is given for those symbols defined by <TT>equ</TT> or <TT>defl</TT>. The <TT>/</TT> prefix is shown for common blocks. <P> The <TT>.rel</TT> file format can store symbol names of up to 7 characters in length. However, MACRO-80 truncates symbols to 6 characters so that it has one character in reserve for extending linking operations such as subtracting two externals from each other. To be compatible (and sensible), <TT>--rel</TT> truncates externals to 6 characters. For MRAS compatibility, <TT>--mras</TT> truncates symbols to 7 characters. This is not a problem for MRAS as it doesn't support extended linking. But necessary if you want zmac to produce <TT>.rel</TT> files that will link with MRAS generated <TT>.rel</TT> files. The <TT>--rel7</TT> option sets symbol truncation to 7 characters so you can assemble files that will link with MRAS output. However, it will break extended linking on labels longer than 6 characters. <P> The <A NAME="prime">ignoring</A> of single quotes can be handy for tracking alternate register usage. Consider the following code fragment: <P> <TABLE> <TR><TD VALIGN="TOP"><PRE><TT>ld a,(hl)</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT>rra</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT>exx</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT>ld a,(hl')</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT>ex af,af'</TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE><TT>ld a',(hl') </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE></TT>rra'<TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE></TT>ex af,af'<TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE></TT>djnz' loop<TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE></TT>ld d',e'<TT> </PRE></TD><TD> </TD></TR> <TR><TD VALIGN="TOP"><PRE></TT>exx<TT> </TD></TR> </TABLE> <P> Although zmac does nothing but ignore the single quotes they are useful for indicating which register we're talking using. A more advanced mode where zmac pays attention to the trailing quotes and emits exchange instrucitons as needed has been considered. <P> <HR> <H3>Exit Status</H3> <P> <TABLE> <TR><TD VALIGN="TOP"><PRE>0 </PRE></TD><TD>No errors. </TD></TR> <TR><TD VALIGN="TOP"><PRE>1 </PRE></TD><TD>One or more errors were found during assembly, or zmac exited with a fatal error. </TD></TR> </TABLE> <P> <HR> <H3>Credits</H3> Bruce Norskog originally wrote zmac in 1978. <P> Updates and bugfixes over the years by John Providenza, Colin Kelley, and more recently by Russell Marks, Mark RISON, Chris Smith, Matthew Phillips and Tim Mann. <P> Extensive modifications for cycle counting, multiple output formats, ".rel" output, 8080 mode and older assembler compatibilty were written by George Phillips. <P> This document was based on Russell Marks zmac man page which had tweaks by Mark RISON and Tim Mann. George Phillips converted it to HTML and documented the new features and some older ones (e.g., </TT>phase<TT>/</TT>dephase<TT>). </TT> <p xmlns:dct="http://purl.org/dc/terms/" xmlns:vcard="http://www.w3.org/2001/vcard-rdf/3.0#"> <a rel="license" href="http://creativecommons.org/publicdomain/zero/1.0/"> <img src="http://i.creativecommons.org/p/zero/1.0/88x31.png" style="border-style: none;" alt="CC0" /> </a> <br /> To the extent possible under law, <a rel="dct:publisher" href="http://48k.ca/zmac.html"> <span property="dct:title">George Phillips</span></a> has waived all copyright and related or neighboring rights to <span property="dct:title">zmac macro cross assembler for the Zilog Z-80 microprocessor</span>. This work is published from: <span property="vcard:Country" datatype="dct:ISO3166" content="CA" about="http://48k.ca/zmac.html"> Canada</span>. </p> <!-- If you ran "zmac --doc" you may want to send the output to a file using "zmac --doc >zmac.html" and then open zmac.html in your web browser. -->