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Diffstat (limited to 'doc')
| -rw-r--r-- | doc/casm.html | 168 |
1 files changed, 147 insertions, 21 deletions
diff --git a/doc/casm.html b/doc/casm.html index 9553a15..100abdc 100644 --- a/doc/casm.html +++ b/doc/casm.html @@ -163,9 +163,7 @@ banks of RAM can be added by using the <b>bank</b> or <b>org</b> directives. Banks are numbered from zero upwards.</p> -<h2>Source Code</h2> - -<h3>Layout</h3> +<h2>Source Code Layout</h2> The source files follow this basic format: @@ -229,7 +227,7 @@ to put the other quote type inside the string.</li> </ul> -<h3>Recognised directives</h3> +<h2>Recognised directives</h2> <p>The following directives are also recognised with an optional period (.) in front of them, and are case insensitive. Directives can also be used to @@ -412,7 +410,7 @@ word<br> </table> -<h3>Expressions</h3> +<h2>Expressions</h2> <p>In any of the directives above, where a value is defined, an expression can be entered.</p> @@ -604,7 +602,7 @@ Bitwise XOR. </table> -<h3>Character Sets</h3> +<h2>Character Sets</h2> <p>The assembler has built-in support for a few different character sets. These can be set by using the options `charset` or `codepage`, i.e.</p> @@ -636,22 +634,84 @@ The character codes as used on the Sinclair ZX Spectrum. </td></tr> <tr><td class="cmd"> +cbm +</td> +<td class="def"> +PETSCII as used on the Commodore Business Machine's range from the +PET to the C128. See <a href="https://en.wikipedia.org/wiki/PETSCII"> +https://en.wikipedia.org/wiki/PETSCII</a> more details. +</td></tr> + +<tr><td class="cmd"> zx81 </td> <td class="def"> -The character codes as used on the Sinclair ZX-81. Lower case +The character codes as used on the Sinclair ZX81. Lower case letters are encoded as normal upper case letters and upper case -letter will be encoded as inverse upper case letters. +letter will be encoded as inverse upper case letters. In addition the following +characters that have no corresponding ZX81 character are mapped as: +<table> + +<tr><td class="cmd"> +# +</td> +<td class="def"> +The British Pound sign. </td></tr> <tr><td class="cmd"> -cbm +' </td> <td class="def"> -PETSCII as used on the Commodore Business Machine's range from the -PET to the C128. See <a href="https://en.wikipedia.org/wiki/PETSCII"> -https://en.wikipedia.org/wiki/PETSCII</a> more details. +Inverse double quotes. +</td></tr> + +<tr><td class="cmd"> +\ +</td> +<td class="def"> +Inverse slash. +</td></tr> + +<tr><td class="cmd"> +! +</td> +<td class="def"> +Inverse question mark. </td></tr> + +<tr><td class="cmd"> +| +</td> +<td class="def"> +Inverse space. +</td></tr> + +<tr><td class="cmd"> +~ +</td> +<td class="def"> +Inverse minus sign. +</td></tr> + +<tr><td class="cmd"> +{ } +</td> +<td class="def"> +Inverse round brackets. +</td></tr> + +<tr><td class="cmd"> +` +</td> +<td class="def"> +The newline character. Note that the newline is actually a HALT opcode used to +terminate the line. +</td></tr> + +</table> +</td></tr> + </table> <p>e.g.</p> @@ -678,7 +738,7 @@ https://en.wikipedia.org/wiki/PETSCII</a> more details. </pre> -<h3>Macros</h3> +<h2>Macros</h2> <p> Macros can be defined in one of two ways; either parameterless or with named @@ -743,13 +803,14 @@ be replaced by using the following option, e.g. </pre> <p> -Note that this is enforced when the macro is *used*, not when it is *defined*. +Note that this is enforced when the macro is <u>used</u> not when it is +defined. Also the character must not be quoted, as that will be parsed as a string holding the character code of the character. </p> -<h3>Output Format</h3> +<h2>Output Format</h2> By default the assembled code is written to a file called <b>output</b> as raw binary. The generated output can be controlled with the following options. @@ -801,10 +862,10 @@ A Spectrum emulator TAP file. </td></tr> <tr><td class="cmd"> -<a href="#zx81out">p-file</a> +<a href="#zx81out">zx81</a> </td> <td class="def"> -A ZX-81 emulator P file. +A ZX81 emulator P file. </td></tr> <tr><td class="cmd"> @@ -850,6 +911,71 @@ another TAP file containing a BASIC loader, for example. <h3 id="zx81out">ZX81 .P Output Format</h3> +<p> +Generates a P-file for an emulator. A ZX81 .P file is simply a dump of memory +from the system variables onwards. +</p> + +<p>This format does not support memory blocks (the .P file is not a container +format) and so will only output anything in the first bank used, and using the +<b>output-file</b> for the filename. +</p> + +<p>The output file will be created as a BASIC program, containing a REM +statement holding the machine code, and a command to execute the code. As +such the output will fail if the code in Bank 0 does not start at address 16514. +Your code must also support being executed from this address. +</p> + +<p>Another important thing to note is about the display file. In the ZX81 +memory map the DFILE can move around depending on the size of the program. +The output driver will create a display file for you. The easiest way to +reference this is to read the DFILE system variable when your program starts. +</p> + +<p>Alternatively you can just as easily set up your own display file once +your program starts if you have special requirements, e.g. a display file for +pseudo hi-res. +</p> + + +<h4>ZX81 .P Output Format options</h4> + +<p>The ZX81 output driver supports the following settings that can be set via +an <b>option</b> command. +</p> + +<table> + +<thead><tr><td class="head">Option</td> +<td class="head">Description</td></tr></thead> + +<tr><td class="cmd"> +option zx81-margin, <pal|ntsc> +</td> +<td class="def"> +Sets the MARGIN system variable appropriately either for the PAL or NTSC +TV system. Defaults to PAL. +</td></tr> + +<tr><td class="cmd"> +option zx81-autorun, <on|off> +</td> +<td class="def"> +Whether the ZX81 should auto run the machine code. Defaults to on. +</td></tr> + +<tr><td class="cmd"> +option zx81-collapse-dfile, <on|off> +</td> +<td class="def"> +Whether the display file should be generated collapsed (e.g. for 1K mode). +Defaults to off. +</td></tr> + + +</table> + <h3 id="t64out">C64 T64 Tape Output Format</h3> <p> @@ -876,7 +1002,7 @@ to start the machine code, e.g. <p>Any remaining blocks will be stored as-is without any basic loader.</p> -<h3>Listing</h3> +<h2>Listing</h2> <p> By default no output listing is generated. This can be controlled by the @@ -1088,14 +1214,14 @@ equivalent: <p> For the hidden OUT instruction using the flag register, $00 or $ff depending -on where you're reading, the following are all equivalent, where _value_ can -be any value at all: +on where you're reading, the following are all equivalent, where <i>value</i> +can be any value at all: </p> <pre class="codeblock"> out (c) out (c),f - out (c),<value> + out (c),<i>value</i> </pre> |