5 files changed, 42 insertions, 7 deletions
diff --git a/680.inc b/680.inc
index 3578ea9..20f3bed 100644
--- a/680.inc
+++ b/680.inc
@@ -11,11 +11,11 @@ ehl	EQUR	d6
 eixy	EQUR	d7
 
 SAVEREG	MACRO
-	movem	d3-d7/a3-a6,-(sp)
+	movem.l	d3-d7/a3-a6,-(sp)
 	ENDM
 
 RESTREG	MACRO
-	movem	(sp)+,d3-d7/a3-a6
+	movem.l	(sp)+,d3-d7/a3-a6
 	ENDM
 
 ;; pushm	MACRO
diff --git a/Makefile b/Makefile
index 262bfe3..f3bb30f 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 ASM_FILES=alu.asm flags.asm opcodes.asm ports.asm interrupts.asm main.asm
 ASM=main.asm
-C_FILES=loader.c bankswap.c video.c misc.c
+C_FILES=loader.c bankswap.c video.c misc.c debug.c
 
 TIGCCFLAGS=-Wall
 CFLAGS=-Wall -ltifiles
diff --git a/debug.c b/debug.c
new file mode 100644
index 0000000..332ae16
--- /dev/null
+++ b/debug.c
@@ -0,0 +1,14 @@
+/* Debugging routines for 680 project.
+ *
+ * Includes debug output.
+ *
+ * Copyright 2010, Duncan Smith
+ * GPL
+ */
+
+#include <stdio.h>
+
+void char_draw(char c)
+{
+	putchar((short)c);
+}
diff --git a/loader.c b/loader.c
index 97f2d4c..75654f4 100644
--- a/loader.c
+++ b/loader.c
@@ -12,7 +12,12 @@
 
 HANDLE page_handles[256];
 
-char infloop[16] = { 0xC3, 0x40, 0, 0, 0, 0 };
+char infloop[16] = { 0xC3, 0x40,	// JP 4000h
+		     0, 0, 0, 0 };
+char writestr[16] = { 0x3E, 0x41,	// LD A,'A'
+		      0xD3, 0x00,	// OUT 00h,A
+		      0xC3, 0x40, 0x00	// JP 4000h
+};
 
 void init_load(void);
 void *deref_page(int);
@@ -58,7 +63,7 @@ void init_load(void)
 	mem_page_0 = pages[0];
 	mem_page_loc_0 = 0;
 //	mem_page_1 = pages[0x1f];
-	mem_page_1 = infloop;
+	mem_page_1 = writestr;
 	mem_page_loc_1 = 0x1f;
 	mem_page_2 = pages[0];
 	mem_page_loc_2 = 0;
diff --git a/ports.asm b/ports.asm
index 5834ae5..c7b43e4 100644
--- a/ports.asm
+++ b/ports.asm
@@ -4,7 +4,10 @@
 	;; Port is in d0, byte is in d1
 	;; Destroys a0
 port_in:
-	movea	lut_ports_in(pc,d0),a0
+	andi.w	#$ff,d0
+	add.w	d0,d0
+	add.w	d0,d0
+	movea.l	lut_ports_in(pc,d0),a0
 	jmp	(a0)
 	rts
 
@@ -267,7 +270,10 @@ lut_ports_in:
 	dc.l	port_in_ff
 
 port_out:
-	movea	lut_ports_out(pc,d0.w),a0
+	andi.w	#$ff,d0
+	add.w	d0,d0
+	add.w	d0,d0
+	movea.l	lut_ports_out(pc,d0.w),a0
 	jmp	(a0)
 	rts
 
@@ -531,6 +537,16 @@ lut_ports_out:
 
 port_in_00:
 port_out_00:
+	;; Temporary test harness.  Writing to this port writes a
+	;; character to the screen.
+	SAVEREG
+	andi.w	#$ff,d1
+	move.w	d1,-(sp)
+	jsr	char_draw
+	addq	#2,sp
+	RESTREG
+	rts
+
 port_in_01:
 port_out_01:
 port_in_02: