Added ZX81 output driver

15 files changed, 558 insertions, 52 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
+&apos;
 </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, &lt;pal|ntsc&gt;
+</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, &lt;on|off&gt;
+</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, &lt;on|off&gt;
+</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>
 
 
diff --git a/src/Makefile b/src/Makefile
index 0812105..29ef34c 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -41,7 +41,8 @@ SOURCE	=	casm.c		\
 		z80.c		\
 		rawout.c	\
 		specout.c	\
-		t64out.c
+		t64out.c	\
+		zx81out.c
 
 OBJECTS	=	casm.o		\
 		expr.o		\
@@ -60,7 +61,8 @@ OBJECTS	=	casm.o		\
 		z80.o		\
 		rawout.o	\
 		specout.o	\
-		t64out.o
+		t64out.o	\
+		zx81out.o
 
 $(TARGET): $(OBJECTS)
 	$(CC) $(CLAGS) -o $(TARGET) $(OBJECTS)
@@ -73,7 +75,7 @@ clean:
 alias.o: alias.c global.h basetype.h util.h state.h alias.h
 casm.o: casm.c global.h basetype.h util.h state.h expr.h label.h macro.h \
   cmd.h parse.h codepage.h stack.h listing.h alias.h output.h rawout.h \
-  specout.h z80.h 6502.h
+  specout.h t64out.h zx81out.h z80.h 6502.h
 codepage.o: codepage.c global.h basetype.h util.h state.h codepage.h \
   parse.h cmd.h
 expr.o: expr.c global.h basetype.h util.h state.h expr.h label.h
@@ -84,7 +86,7 @@ listing.o: listing.c global.h basetype.h util.h state.h label.h macro.h \
 macro.o: macro.c global.h basetype.h util.h state.h codepage.h parse.h \
   cmd.h varchar.h macro.h
 output.o: output.c global.h basetype.h util.h state.h output.h parse.h \
-  cmd.h rawout.h specout.h t64out.h
+  cmd.h rawout.h specout.h t64out.h zx81out.h
 parse.o: parse.c global.h basetype.h util.h state.h codepage.h parse.h \
   cmd.h
 rawout.o: rawout.c global.h basetype.h util.h state.h rawout.h parse.h \
@@ -100,3 +102,5 @@ varchar.o: varchar.c global.h basetype.h util.h state.h codepage.h \
   parse.h cmd.h varchar.h
 z80.o: z80.c global.h basetype.h util.h state.h expr.h label.h parse.h \
   cmd.h codepage.h varchar.h z80.h
+zx81out.o: zx81out.c global.h basetype.h util.h state.h codepage.h \
+  parse.h cmd.h zx81out.h
diff --git a/src/casm.c b/src/casm.c
index 7624978..bad07f1 100644
--- a/src/casm.c
+++ b/src/casm.c
@@ -40,10 +40,7 @@
 #include "stack.h"
 #include "listing.h"
 #include "alias.h"
-
 #include "output.h"
-#include "rawout.h"
-#include "specout.h"
 
 /* ---------------------------------------- PROCESSORS
 */
@@ -404,6 +401,14 @@ static CommandStatus OPTION(const char *label, int argc, char *argv[],
     {
         return SpecTAPOutputSetOption(entry->value, ac, args, q, err, errsize);
     }
+    else if ((entry = ParseTable(opt, T64OutputOptions())))
+    {
+        return T64OutputSetOption(entry->value, ac, args, q, err, errsize);
+    }
+    else if ((entry = ParseTable(opt, ZX81OutputOptions())))
+    {
+        return ZX81OutputSetOption(entry->value, ac, args, q, err, errsize);
+    }
     else if ((entry = ParseTable(opt, cpu->options())))
     {
         return cpu->set_option(entry->value, ac, args, q, err, errsize);
diff --git a/src/codepage.c b/src/codepage.c
index 4cbc1bc..cecdf66 100644
--- a/src/codepage.c
+++ b/src/codepage.c
@@ -101,8 +101,8 @@ static CodepageDef cp_ascii[] =
 
 static CodepageDef cp_zx81[] =
 {
-    {' ', 0x00}, {'!', 0x00}, {'"', 0x0b}, {'#', 0x0c}, 
-    {'$', 0x0d}, {'%', 0x00}, {'&', 0x00}, {'\'', 0x0b}, 
+    {' ', 0x00}, {'!', 0x8f}, {'"', 0x0b}, {'#', 0x0c}, 
+    {'$', 0x0d}, {'%', 0x00}, {'&', 0x00}, {'\'', 0x8b}, 
     {'(', 0x10}, {')', 0x11}, {'*', 0x17}, {'+', 0x15}, 
     {',', 0x1a}, {'-', 0x16}, {'.', 0x1b}, {'/', 0x24}, 
     {'0', 0x1c}, {'1', 0x1d}, {'2', 0x1e}, {'3', 0x1f}, 
@@ -116,15 +116,15 @@ static CodepageDef cp_zx81[] =
     {'P', 0xb5}, {'Q', 0xb6}, {'R', 0xb7}, {'S', 0xb8}, 
     {'T', 0xb9}, {'U', 0xba}, {'V', 0xbb}, {'W', 0xbc}, 
     {'X', 0xbd}, {'Y', 0xbe}, {'Z', 0xbf}, {'[', 0x10}, 
-    {'\\', 0x24}, {']', 0x11}, {'^', 0xde}, {'_', 0x80}, 
-    {'`', 0x60}, {'a', 0x26}, {'b', 0x27}, {'c', 0x28}, 
+    {'\\', 0x98}, {']', 0x11}, {'^', 0xde}, {'_', 0x80}, 
+    {'`', 0x76}, {'a', 0x26}, {'b', 0x27}, {'c', 0x28}, 
     {'d', 0x29}, {'e', 0x2a}, {'f', 0x2b}, {'g', 0x2c}, 
     {'h', 0x2d}, {'i', 0x2e}, {'j', 0x2f}, {'k', 0x30}, 
     {'l', 0x31}, {'m', 0x32}, {'n', 0x33}, {'o', 0x34}, 
     {'p', 0x35}, {'q', 0x36}, {'r', 0x37}, {'s', 0x38}, 
     {'t', 0x39}, {'u', 0x3a}, {'v', 0x3b}, {'w', 0x3c}, 
     {'x', 0x3d}, {'y', 0x3e}, {'z', 0x3f}, {'{', 0x90}, 
-    {'|', 0x00}, {'}', 0x91}, {'~', 0x96},
+    {'|', 0x80}, {'}', 0x91}, {'~', 0x96},
     {0, 0}
 };
 
diff --git a/src/example/Makefile b/src/example/Makefile
index e9ddfce..7c53209 100644
--- a/src/example/Makefile
+++ b/src/example/Makefile
@@ -20,18 +20,24 @@
 # Makefile for examples
 #
 
-ALL	= spectrum.tap c64.t64 # zx81.p
+ALL	= spectrum.tap c64.t64 zx81.p
 CASM	= ../casm
 
-all: $(ALL)
+all: $(ALL) $(CASM)
+
+$(CASM): ../*.[ch]
+	cd .. ; make
 
 remake: clean all
 
-spectrum.tap: spectrum.asm
+spectrum.tap: spectrum.asm $(CASM)
 	$(CASM) spectrum.asm
 
-c64.t64: c64.asm
+c64.t64: c64.asm $(CASM)
 	$(CASM) c64.asm
 
+zx81.p: zx81.asm $(CASM)
+	$(CASM) zx81.asm
+
 clean:
 	rm -f $(ALL)
diff --git a/src/example/zx81.asm b/src/example/zx81.asm
new file mode 100644
index 0000000..3a0021c
--- /dev/null
+++ b/src/example/zx81.asm
@@ -0,0 +1,34 @@
+	; Simple example ZX81 code
+	;
+
+	option	output-file,zx81.p
+	option	output-format,zx81
+
+	option	zx81-margin,pal
+	option	zx81-autorun,on
+	option	zx81-collapse-dfile,off
+
+	option	codepage,zx81
+
+DFILE:	equ	16396
+
+	org 16514
+
+	ld	hl,(DFILE)
+	inc	hl
+	ld	de,hello
+loop:
+	ld	a,(de)
+	cp	255
+	ret	z
+	ld	(hl),a
+	inc	hl
+	inc	de
+
+	ld	a,(hl)
+	cp	$76
+	jr	nz,loop
+	inc	hl
+	jr	loop
+
+hello:	db	"HELLO|WORLD hello world (#69.99 well spent)",255
diff --git a/src/label.c b/src/label.c
index c15627f..75270ef 100644
--- a/src/label.c
+++ b/src/label.c
@@ -277,17 +277,17 @@ int LabelExpand(const char *expr, int *result)
         {
             found = ParseBase(expr + 1, 16, result, '\0');
         }
-        else if (last == 'h')
+        else if (last == 'h' || last == 'H')
         {
-            found = ParseBase(expr, 16, result, 'h');
+            found = ParseBase(expr, 16, result, last);
         }
         else if (first == '%')
         {
             found = ParseBase(expr, 2, result, '\0');
         }
-        else if (last == 'b')
+        else if (last == 'b' || last == 'B')
         {
-            found = ParseBase(expr, 2, result, 'b');
+            found = ParseBase(expr, 2, result, last);
         }
         else if (first == '\'' && last == '\'' && len == 3)
         {
diff --git a/src/output.c b/src/output.c
index 4c03e4e..8476f9d 100644
--- a/src/output.c
+++ b/src/output.c
@@ -28,12 +28,6 @@
 #include "global.h"
 #include "output.h"
 
-#include "rawout.h"
-#include "specout.h"
-#include "t64out.h"
-/* TODO #include "zx81out.h" */
-
-
 /* ---------------------------------------- GLOBALS
 */
 
@@ -56,7 +50,8 @@ typedef enum
 {
     RAW,
     TAP,
-    T64
+    T64,
+    ZX81
 } Format;
 
 static char             output[4096] = "output";
@@ -69,6 +64,7 @@ static ValueTable       format_table[] =
     {"raw",             RAW},
     {"spectrum",        TAP},
     {"t64",             T64},
+    {"zx81",            ZX81},
     {NULL}
 };
 
@@ -142,6 +138,10 @@ int OutputCode(void)
             return T64Output(output, output_bank, bank, count,
                              error, sizeof error);
 
+        case ZX81:
+            return ZX81Output(output, output_bank, bank, count,
+                              error, sizeof error);
+
         default:
             break;
     }
diff --git a/src/output.h b/src/output.h
index cb0e5ca..8ea1c1d 100644
--- a/src/output.h
+++ b/src/output.h
@@ -29,6 +29,13 @@
 #include "parse.h"
 #include "cmd.h"
 
+/* Pull in the output drivers
+*/
+#include "rawout.h"
+#include "specout.h"
+#include "t64out.h"
+#include "zx81out.h"
+
 /* ---------------------------------------- INTERFACES
 */
 
diff --git a/src/rawout.c b/src/rawout.c
index 35ff650..3f75b50 100644
--- a/src/rawout.c
+++ b/src/rawout.c
@@ -67,7 +67,7 @@ int RawOutput(const char *filename, const char *filename_bank,
 
         if (!(fp = fopen(name, "wb")))
         {
-            snprintf(error, error_size, "Failed to open %s\n", name);
+            snprintf(error, error_size, "Failed to open %s", name);
             return FALSE;
         }
 
diff --git a/src/specout.c b/src/specout.c
index e5ed897..b29b6ba 100644
--- a/src/specout.c
+++ b/src/specout.c
@@ -81,7 +81,7 @@ int SpecTAPOutput(const char *filename, const char *filename_bank,
 
     if (!fp)
     {
-        snprintf(error, error_size, "Failed to create %s\n", filename);
+        snprintf(error, error_size, "Failed to create %s", filename);
         return FALSE;
     }
 
diff --git a/src/t64out.c b/src/t64out.c
index 0fd308f..6aa82f2 100644
--- a/src/t64out.c
+++ b/src/t64out.c
@@ -122,7 +122,7 @@ int T64Output(const char *filename, const char *filename_bank,
 
     if (!fp)
     {
-        snprintf(error, error_size, "Failed to create %s\n", filename);
+        snprintf(error, error_size, "Failed to create %s", filename);
         return FALSE;
     }
 
diff --git a/src/t64out.h b/src/t64out.h
index 2743d0e..b4c5103 100644
--- a/src/t64out.h
+++ b/src/t64out.h
@@ -43,7 +43,7 @@ CommandStatus T64OutputSetOption(int opt, int argc, char *argv[],
                                  size_t error_size);
 
 
-/* Spectrum TAP output of assembly.  Returns TRUE if OK, FALSE for failure.
+/* C64 T64 tape output of assembly.  Returns TRUE if OK, FALSE for failure.
 */
 int T64Output(const char *filename, const char *filename_bank,
               MemoryBank **bank, int count,
diff --git a/src/zx81out.c b/src/zx81out.c
new file mode 100644
index 0000000..fe4d83c
--- /dev/null
+++ b/src/zx81out.c
@@ -0,0 +1,268 @@
+/*
+
+    casm - Simple, portable assembler
+
+    Copyright (C) 2003-2015  Ian Cowburn (ianc@noddybox.demon.co.uk)
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+    -------------------------------------------------------------------------
+
+    ZX81 tape output handler.
+
+*/
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "global.h"
+#include "codepage.h"
+#include "zx81out.h"
+
+
+/* ---------------------------------------- MACROS & TYPES
+*/
+
+enum option_t
+{
+    OPT_MARGIN,
+    OPT_AUTORUN,
+    OPT_DFILE_COLLAPSED
+};
+
+static const ValueTable option_set[] =
+{
+    {"zx81-margin",             OPT_MARGIN},
+    {"zx81-autorun",            OPT_AUTORUN},
+    {"zx81-collapse-dfile",     OPT_DFILE_COLLAPSED},
+    {NULL}
+};
+
+typedef enum
+{
+    PAL = 55,
+    NTSC = 31
+} TVFormat;
+
+static ValueTable       format_table[] =
+{
+    {"pal",             PAL},
+    {"NTSC",            NTSC},
+    {NULL}
+};
+
+static TVFormat         tv_format = PAL;
+static int              run = TRUE;
+static int              collapse_dfile = FALSE;
+
+/* ---------------------------------------- PRIVATE FUNCTIONS
+*/
+
+static int PokeB(Byte *mem, int addr, Byte b)
+{
+    mem[addr++] = b;
+    return (addr % 0x10000);
+}
+
+
+static int PokeW(Byte *mem, int addr, int w)
+{
+    addr = PokeB(mem, addr, w & 0xff);
+    return PokeB(mem, addr, (w & 0xff00) >> 8);
+}
+
+
+/* ---------------------------------------- INTERFACES
+*/
+const ValueTable *ZX81OutputOptions(void)
+{
+    return option_set;
+}
+
+CommandStatus ZX81OutputSetOption(int opt, int argc, char *argv[],
+                                     int quoted[],
+                                     char *err, size_t errsize)
+{
+    const ValueTable *val;
+
+    CMD_ARGC_CHECK(1);
+
+    switch(opt)
+    {
+        case OPT_MARGIN:
+            CMD_TABLE(argv[0], format_table, val);
+            tv_format = val->value;
+            break;
+
+        case OPT_AUTORUN:
+            run = ParseTrueFalse(argv[0], TRUE);
+            break;
+
+        case OPT_DFILE_COLLAPSED:
+            collapse_dfile = ParseTrueFalse(argv[0], TRUE);
+            break;
+
+        default:
+            break;
+    }
+
+    return CMD_OK;
+}
+
+int ZX81Output(const char *filename, const char *filename_bank,
+              MemoryBank **bank, int count, char *error, size_t error_size)
+{
+    static const int line[] =
+    {
+        0, 10, 14, 0, 0xf9, 0xd4, 0x1d, 0x22, 0x21, 0x1d,
+        0x20, 0x7e, 0x8f, 0x01, 0x04, 0x00, 0x00, 0x76, -1
+    };
+
+    FILE *fp = fopen(filename, "wb");
+    Byte *mem;
+    int min;
+    int max;
+    int len;
+    int next;
+    int dfile;
+    int vars;
+    int addr;
+    int f;
+
+    mem = bank[0]->memory;
+    min = bank[0]->min_address_used;
+    max = bank[0]->max_address_used;
+
+    len = max - min + 1;
+
+    if (min != 16514)
+    {
+        snprintf(error, error_size, "Code must start at 16514 to work with the "
+                                        "ZX81 output driver.");
+        return FALSE;
+    }
+
+    if (!fp)
+    {
+        snprintf(error, error_size, "Failed to create %s", filename);
+        return FALSE;
+    }
+
+    /* Create the system variables and BASIC program around the supplied code.
+       BASIC is done first to calculate various system variables.
+    */
+    addr = 16509;
+
+    /* Program line with REM statement
+    */
+    addr = PokeW(mem, addr, 0x0000);            /* Line number  */
+    addr = PokeW(mem, addr, len + 2);           /* Line length  */
+    addr = PokeB(mem, addr, 0xea);              /* REM token    */
+
+    addr += len;                                /* Skip code    */
+
+    addr = PokeB(mem, addr, 0x76);              /* NL token     */
+
+    /* Program line to launch the code
+    */
+    next = addr;
+
+    f = 0;
+    while (line[f] != -1)
+    {
+    	addr = PokeB(mem, addr, line[f++]);
+    }
+
+    /* Display file
+    */
+    dfile = addr;
+
+    if (collapse_dfile)
+    {
+        for(f = 0; f < 25; f++)
+        {
+            addr = PokeB(mem, addr, 0x76);
+        }
+    }
+    else
+    {
+        addr = PokeB(mem, addr, 0x76);
+
+        for(f = 0; f < 24; f++)
+        {
+            int n;
+
+            for(n = 0; n < 32; n++)
+            {
+                addr = PokeB(mem, addr, 0);
+            }
+
+            addr = PokeB(mem, addr, 0x76);
+        }
+    }
+
+    /* Vars
+    */
+    vars = addr;
+    addr = PokeB(mem, addr, 0x80);
+
+    /* System variables
+    */
+    addr = 0x4009;
+
+    addr = PokeB(mem, addr, 0);                 /* VERSN        */
+    addr = PokeW(mem, addr, 0);                 /* E_PPC        */
+    addr = PokeW(mem, addr, dfile);             /* D_FILE       */
+    addr = PokeW(mem, addr, dfile + 1);         /* DF_CC        */
+    addr = PokeW(mem, addr, vars);              /* VARS         */
+    addr = PokeW(mem, addr, 0);                 /* DEST         */
+    addr = PokeW(mem, addr, vars + 1);          /* E_LINE       */
+    addr = PokeW(mem, addr, vars - 1);          /* CH_ADD       */
+    addr = PokeW(mem, addr, 0);                 /* X_PTR        */
+    addr = PokeW(mem, addr, vars + 5);          /* STKBOT       */
+    addr = PokeW(mem, addr, vars + 5);          /* STKEND       */
+    addr = PokeB(mem, addr, 0);                 /* BREG         */
+    addr = PokeW(mem, addr, 16477);             /* MEM          */
+    addr = PokeB(mem, addr, 0);                 /* unused       */
+    addr = PokeB(mem, addr, 2);                 /* DF_SZ        */
+    addr = PokeW(mem, addr, 2);                 /* S_TOP        */
+    addr = PokeW(mem, addr, 0xffff);            /* LAST_K       */
+    addr = PokeB(mem, addr, 0xff);              /* LAST_K       */
+    addr = PokeB(mem, addr, tv_format);         /* MARGIN       */
+    addr = PokeW(mem, addr, run ? next : dfile);/* NXTLIN       */
+    addr = PokeW(mem, addr, 0);                 /* OLDPPC       */
+    addr = PokeB(mem, addr, 0);                 /* FLAGX        */
+    addr = PokeW(mem, addr, 0);                 /* STRLEN       */
+    addr = PokeW(mem, addr, 0xc8d);             /* T_ADDR       */
+    addr = PokeW(mem, addr, 0);                 /* SEED         */
+    addr = PokeW(mem, addr, 0x0ffff);           /* FRAMES       */
+    addr = PokeW(mem, addr, 0);                 /* COORDS       */
+    addr = PokeB(mem, addr, 0xbc);              /* PR_CC        */
+    addr = PokeB(mem, addr, 33);                /* S_POSN       */
+    addr = PokeB(mem, addr, 24);                /* S_POSN       */
+    addr = PokeW(mem, addr, 0x40);              /* CDFLAG       */
+
+    /* Write the constructed P file
+    */
+    fwrite(mem + 0x4009, vars - 0x4009 + 1, 1, fp);
+
+    fclose(fp);
+
+    return TRUE;
+}
+
+
+/*
+vim: ai sw=4 ts=8 expandtab
+*/
diff --git a/src/zx81out.h b/src/zx81out.h
new file mode 100644
index 0000000..e6f3190
--- /dev/null
+++ b/src/zx81out.h
@@ -0,0 +1,56 @@
+/*
+
+    casm - Simple, portable assembler
+
+    Copyright (C) 2003-2015  Ian Cowburn (ianc@noddybox.demon.co.uk)
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+    -------------------------------------------------------------------------
+
+    ZX81 .P file output
+
+*/
+
+#ifndef CASM_ZX81OUT_H
+#define CASM_ZX81OUT_H
+
+#include "parse.h"
+#include "state.h"
+#include "cmd.h"
+
+/* ---------------------------------------- INTERFACES
+*/
+
+
+/* RAW Output options
+*/
+const ValueTable *ZX81OutputOptions(void);
+
+CommandStatus ZX81OutputSetOption(int opt, int argc, char *argv[],
+                                  int quoted[], char *error,
+                                  size_t error_size);
+
+
+/* ZX81 P file output of assembly.  Returns TRUE if OK, FALSE for failure.
+*/
+int ZX81Output(const char *filename, const char *filename_bank,
+              MemoryBank **bank, int count,
+              char *error, size_t error_size);
+
+#endif
+
+/*
+vim: ai sw=4 ts=8 expandtab
+*/