Fixes to actually run code

This is the version to run the first (trivial) infinite loop
correctly.  I hacked up the loader slightly to replace one of the
(nonexistent) pages with a static byte array.

z80 code executed:

$4000:
	JP	$4000

4000  c3 40 00
4003

This version also draws the opcode executed on the screen, to aid in
debugging the emulator:

        move.b  d0,$4c00+32*(128/8)

Also, it turns out that I was mixing up the emulated SP (a4) and emulated
PC (a6).  That has been fixed.

Further, it seems that movea defaults to a word operation in a68k.
This led to pointer corruption, which has been fixed.

5 files changed, 31 insertions, 10 deletions

diff --git a/680.h b/680.h
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/680.h
diff --git a/loader.c b/loader.c
index 56561c0..97f2d4c 100644
--- a/loader.c
+++ b/loader.c
@@ -8,9 +8,11 @@
 #include <tigcclib.h>
 #include "asm_vars.h"
 
+#include "680.h"
+
 HANDLE page_handles[256];
 
-char infloop[16] = { 0xc3, 0, 0, 0 };
+char infloop[16] = { 0xC3, 0x40, 0, 0, 0, 0 };
 
 void init_load(void);
 void *deref_page(int);
@@ -55,7 +57,8 @@ void init_load(void)
 
 	mem_page_0 = pages[0];
 	mem_page_loc_0 = 0;
-	mem_page_1 = pages[0x1f];
+//	mem_page_1 = pages[0x1f];
+	mem_page_1 = infloop;
 	mem_page_loc_1 = 0x1f;
 	mem_page_2 = pages[0];
 	mem_page_loc_2 = 0;
diff --git a/main.asm b/main.asm
index 9a4789f..e6f2a54 100644
--- a/main.asm
+++ b/main.asm
@@ -66,8 +66,8 @@ emu_setup:
 	lea	flag_storage,a3
 	move.w	#$4000,d1
 	bsr	deref
-	move	a0,a6
-	move	a0,a4
+	move.l	a0,a6
+	move.l	a0,a4
 
 	rts
 
diff --git a/misc.c b/misc.c
new file mode 100644
index 0000000..9224145
--- /dev/null
+++ b/misc.c
@@ -0,0 +1,17 @@
+/* Miscellaneous C routines for 680 project.
+ *
+ * Error handling, for now.
+ *
+ * Copyright 2010, Duncan Smith
+ * GPL
+ */
+
+#include <tigcclib.h>
+#include "asm_vars.h"
+
+/* SOMETHING WENT HORRIBLY HORRIBLY WRONG
+ */
+void throw_error(char *message)
+{
+	return;
+}
diff --git a/opcodes.asm b/opcodes.asm
index fe5547c..8042296 100644
--- a/opcodes.asm
+++ b/opcodes.asm
@@ -108,7 +108,8 @@ _align	SET	_align+$20
 	;; This is run at the end of every instruction routine.
 DONE	MACRO
 	clr.w	d0		; 4 cycles / 2 bytes
-	move.b	(a4)+,d0	; 8 cycles / 2 bytes
+	move.b	(a6)+,d0	; 8 cycles / 2 bytes
+	move.b	d0,$4c00+32*(128/8)
 	rol.w	#5,d0		;16 cycles / 2 bytes
 	jmp	0(a5,d0.w)	;14 cycles / 4 bytes
 	;; overhead:		 42 cycles /10 bytes
@@ -602,7 +603,7 @@ emu_op_31:
 	;; LD	SP,immed.w
 	FETCHWI	d1
 	bsr	deref
-	movea	a0,a4
+	movea.l	a0,a4
 	DONE
 
 	START
@@ -1792,7 +1793,7 @@ emu_op_c3:			; S12 T36
 	;; PC <- immed.w
 	FETCHWI	d1
 	bsr	deref
-	movea	a0,a6
+	movea.l	a0,a6
 	DONE
 
 	START
@@ -1844,7 +1845,7 @@ emu_op_c9:
 	;; SP <- (SP+2)
 	POPW	d1
 	bsr	deref
-	movea	a0,a6
+	movea.l	a0,a6
 	DONE
 
 	START
@@ -2095,7 +2096,7 @@ emu_op_e9:
 	;; JP	(HL)
 	FETCHB	d6,d1
 	bsr	deref
-	movea	a0,a6
+	movea.l	a0,a6
 	DONE
 
 	START
@@ -2225,7 +2226,7 @@ emu_op_f9:
 	;; SP <- HL
 	move.w	d6,d1
 	bsr	deref
-	movea	a0,a4
+	movea.l	a0,a4
 	DONE
 
 	START