gr-sim: combine the 6502 emulation stuff

gr-sim/6502_emulate.c

@@ -10,6 +10,24 @@ unsigned char ram[RAMSIZE];
 
 /* Registers */
 unsigned char a,y,x;
+unsigned short sp;
+
+/* Flags */
+unsigned int n,z,c,v;
+
+int init_6502(void) {
+
+	a=0;
+	y=0;
+	x=0;
+
+	sp=0x1ff;
+
+	n=0; z=0; c=0; v=0;
+
+	return 0;
+
+}
 
 unsigned short y_indirect(unsigned char base, unsigned char y) {
 
@@ -23,3 +41,67 @@ unsigned short y_indirect(unsigned char base, unsigned char y) {
 
 }
 
+void adc(int value) {
+
+	int temp_a;
+	int temp_value;
+	int result;
+
+	temp_a=a&0xff;
+	temp_value=value&0xff;
+
+	result=(temp_a+temp_value+c);
+
+	c=(result&0x100)>>8;
+	n=(result&0x80)>>7;
+
+	v=!!((a^result)&(value^result)&0x80);
+
+	a=result&0xff;
+	z=(a==0);
+
+}
+
+void sbc(int value) {
+	int temp_a;
+	int result;
+	int temp_value;
+
+	temp_a=a&0xff;
+	temp_value=value&0xff;
+
+	result=temp_a-temp_value-(!c);
+
+	c=(result&0x100)>>8;
+	n=(result&0x80)>>7;
+
+	v=!!((a^result)&((255-value)^result)&0x80);
+
+	a=result&0xff;
+	z=(a==0);
+}
+
+void cmp(int value) {
+
+	int temp_a;
+	int temp_value;
+
+	temp_a=a&0xff;
+	temp_value=value&0xff;
+	temp_a=temp_a-temp_value;
+	c=(temp_a&0x100)>>8;
+	n=(temp_a&0x80)>>7;
+	z=(a==0);
+}
+
+void pha(void) {
+
+	sp--;
+	ram[sp]=a;
+}
+
+void pla(void) {
+
+	a=ram[sp];
+	sp++;
+}

gr-sim/6502_emulate.h

@@ -1,4 +1,14 @@
 #define RAMSIZE	128*1024
 extern unsigned char ram[RAMSIZE];
 extern unsigned char a,y,x;
+extern unsigned short sp;
+extern unsigned int n,z,c,v;
+
 unsigned short y_indirect(unsigned char base, unsigned char y);
+int init_6502(void);
+void adc(int value);
+void sbc(int value);
+void cmp(int value);
+void pha(void);
+void pla(void);
+

gr-sim/l4d.c

@@ -18,62 +18,6 @@ static unsigned char input[MAX_INPUT];
 #define A4L	0x42
 #define A4H	0x43
 
-static short s;
-static int n,z,c,v;
-
-void adc(int value) {
-
-	int temp_a;
-	int temp_value;
-	int result;
-
-	temp_a=a&0xff;
-	temp_value=value&0xff;
-
-	result=(temp_a+temp_value+c);
-
-	c=(result&0x100)>>8;
-	n=(result&0x80)>>7;
-
-	v=!!((a^result)&(value^result)&0x80);
-
-	a=result&0xff;
-	z=(a==0);
-
-}
-
-void sbc(int value) {
-	int temp_a;
-	int result;
-	int temp_value;
-
-	temp_a=a&0xff;
-	temp_value=value&0xff;
-
-	result=temp_a-temp_value-(!c);
-
-	c=(result&0x100)>>8;
-	n=(result&0x80)>>7;
-
-	v=!!((a^result)&((255-value)^result)&0x80);
-
-	a=result&0xff;
-	z=(a==0);
-}
-
-void cmp(int value) {
-
-	int temp_a;
-	int temp_value;
-
-	temp_a=a&0xff;
-	temp_value=value&0xff;
-	temp_a=temp_a-temp_value;
-	c=(temp_a&0x100)>>8;
-	n=(temp_a&0x80)>>7;
-	z=(a==0);
-}
-
 static void getsrc(void) {
 //getsrc:
 	a=ram[y_indirect(src,y)];		// lda 	(src), y
@@ -85,18 +29,6 @@ done_getsrc: ;
 	//+	rts
 }
 
-static void pha(void) {
-
-	s--;
-	ram[s]=a;
-}
-
-static void pla(void) {
-
-	a=ram[s];
-	s++;
-}
-
 void buildcount(void) {
 
 //buildcount:
@@ -161,6 +93,8 @@ int main(int argc, char **argv) {
 	int size;
 	short orgoff,paksize,pakoff;
 
+	init_6502();
+
 	fff=fopen("../mockingboard/outi.raw.lz4","r");
 	if (fff==NULL) {
 		fprintf(stderr,"Error opening!\n");
@@ -174,8 +108,6 @@ int main(int argc, char **argv) {
 
 	memcpy(&ram[0x2000],input,size);
 
-	s=0x1ff;
-
 	//LZ4 data decompressor for Apple II
 	//Peter Ferrie (peter.ferrie@gmail.com)