Initial commit.

6510.h

@@ -0,0 +1,62 @@
+/* 6510.h - processor emulation for C64 emulator */
+/* by Brian Huffman 11-29-00 */
+
+//void cpu6510_main (int cycles);
+void cpu6510_main (void);
+
+void cpu6510_reset (void);
+void cpu6510_irq (void);
+void cpu6510_nmi (void);
+void cpu6510_brk (void);
+
+void print_state (void);
+
+void cpu6510_bad_line (void);
+
+void cpu6510_callback (int source, void (*callback)(void), int time);
+int cpu6510_clock (void);
+
+enum {
+	CB_NONE,
+	CB_MAIN,
+	CB_RASTER,
+	CB_REDRAW,
+	CB_FRAME,
+	CB_TIMER1A,
+	CB_TIMER1B,
+	CB_MAX
+};
+/*
+typedef struct CPUState {
+
+	// processor registers
+	// 16-bit: pc
+	// 8-bit: a,x,y,s,p
+	// 1-bit: c,z,i,d,b,v,n
+	int reg_pc;
+	int reg_a;
+	int reg_x;
+	int reg_y;
+	int reg_s;
+	int reg_p;
+	int flag_n;
+	int flag_z;
+	int flag_c;
+
+	// cycle counter
+	int clock;
+} CPUState;
+*/
+
+
+
+
+
+
+
+
+
+
+
+
+

6510_addressing.c

@@ -0,0 +1,79 @@
+/* 6510_addressing.c - inline functions for 6510 addressing modes */
+/* this file is included directly into 6510.c */
+
+/* immediate mode */
+inline int addr_imm() {
+  return reg_pc++;
+}
+
+/* zero page */
+inline int addr_zpg() {
+  return mem_read(reg_pc++);
+}
+
+/* absolute */
+inline int addr_abs() {
+  int address = mem_read_16(reg_pc);
+  reg_pc+=2;
+  return address;
+}
+
+/* zero page, x */
+inline int addr_zpx() {
+  int address = mem_read(reg_pc++) + reg_x;
+  return (address &= 0xff);
+}
+
+/* zero page, y */
+inline int addr_zpy() {
+  int address = mem_read(reg_pc++) + reg_y;
+  return (address &= 0xff);
+}
+
+/* absolute, x */
+inline int addr_abx() {
+  int address = mem_read(reg_pc++) + reg_x;
+
+  /* test for page boundary crossing */
+  if (address > 0xff) clock_advance(1);
+
+  return address + (mem_read(reg_pc++) << 8);
+}
+
+/* absolute, y */
+inline int addr_aby() {
+  int address = mem_read(reg_pc++) + reg_y;
+
+  /* test for page boundary crossing */
+  if (address > 0xff) clock_advance(1);
+
+  return address + (mem_read(reg_pc++) << 8);
+}
+
+/* indexed indirect */
+inline int addr_inx() {
+  int index = mem_read(reg_pc++) + reg_x;
+  index &= 0xff;
+  return mem_read_16(index);
+}
+
+/* indirect indexed */
+inline int addr_iny() {
+  int index, address;
+
+  index = mem_read(reg_pc++);
+  address = mem_read(index) + reg_y;
+
+  /* test for page boundary crossing */
+  if (address > 0xff) clock_advance(1);
+
+  return address + (mem_read(index + 1) << 8);
+}
+
+/* absolute indirect */
+inline int addr_ind() {
+  int index = mem_read_16(reg_pc);
+  reg_pc += 2;
+  return mem_read_16(index);
+}
+

6510_highlevel.c

@@ -0,0 +1,114 @@
+/* highlevel.c - optimized routines for often-called sections of kernal */
+/* this file should be included directly into 6510.c */
+
+#include "serial.h"
+
+inline static void update_nz(int result) {
+	flag_nz = result;
+}
+
+/* poll keyboard buffer */
+inline void kernal_e5cd() {
+/*
+	e5cd:  LDA $c6  	;a5c6    ;NDX no. of chars in keyboard queue
+	e5cf:  STA $cc  	;85cc    ;BLNSW cursor blink enable, 0=blink
+	e5d1:  STA $0292	;8d9202  ;AUTODN automatic scroll down, 0=ON
+	e5d4:  BEQ $e5cd  	;f0f7    ;loop until keys are pressed
+*/
+
+	reg_a = mem_read(0xc6);
+	mem_write(0xcc, reg_a);
+	mem_write(0x0292, reg_a);
+	update_nz(reg_a);
+	if (reg_a==0) { reg_pc = 0xe5cd; clock_advance(1); }
+	else reg_pc = 0xe5d6;
+	clock_advance(3+3+4+2);
+}
+
+inline void kernal_e9d4() {
+	int address;
+/*
+	e9d4:  LDA ($ac),Y  	;b1ac    ;SAL screen scrolling ptr
+	e9d6:  STA ($d1),Y  	;91d1    ;PNT screen address ptr
+	e9d8:  LDA ($ae),Y  	;b1ae    ;EAL color scrolling ptr
+	e9da:  STA ($f3),Y  	;91f3    ;USER color address ptr
+	e9dc:  DEY 		;88
+	e9dd:  BPL $e9d4  	;10f5    ;loop to copy entire line
+*/
+	address = mem_read(0xac) + reg_y;
+	if (address > 0xff) clock_advance(1);
+	address += (mem_read(0xad) << 8);
+	reg_a = mem_read(address);
+
+	address = mem_read_16(0xd1) + reg_y;
+	mem_write (address, reg_a);
+
+	address = mem_read(0xae) + reg_y;
+	if (address > 0xff) clock_advance(1);
+	address += (mem_read(0xaf) << 8);
+	reg_a = mem_read(address);
+
+	address = mem_read_16(0xf3) + reg_y;
+	mem_write (address, reg_a);
+
+	reg_y = (reg_y - 1) & 0xff;
+	update_nz(reg_y);
+	if ( !(reg_p & N_FLAG) ) { reg_pc = 0xe9d4; clock_advance(1); }
+	else reg_pc = 0xe9df;
+	clock_advance(5+6+5+6+2+2);
+}
+/*
+eab3:  LSR 		;4a      ;check next row
+...
+ead2:  BNE $eab3  	;d0df    ;loop to all rows
+*/
+
+
+/*
+fd6c:  INC $c2  	;e6c2
+...
+fd86:  BEQ $fd6c  	;f0e4    ;loop to check all pages
+*/
+
+/*****************************************/
+/**** serial emulation kernal patches ****/
+/*****************************************/
+
+/* LISTN */
+/* SECND */
+/* TALK */
+/* TKSA */
+/* CIOUT */
+inline void kernal_ed40() {
+	int atn, error;
+
+	atn = mem_read(0xdd00) & 0x08;
+
+	/* $95 = BSOUT, buffered serial char */
+	error = serial_write (atn, mem_read(0x95));
+
+	if (error == SERIAL_DEVICE_NOT_PRESENT) mem_write(0x90, mem_read(0x90) | 0x80);
+	if (error == SERIAL_TIME_OUT) mem_write(0x90, mem_read(0x90) | 0x03);
+	cpu6510_CLI();
+	cpu6510_RTS();
+}
+
+/* ACPTR */
+inline void kernal_ee13() {
+	int result = serial_read ();
+	if (result & SERIAL_END_OF_FILE) mem_write (0x90, mem_read(0x90) | 0x40);
+	if (result == SERIAL_TIME_OUT) mem_write (0x90, mem_read(0x90) | 0x02);
+
+	reg_a = result & 0xff;
+	cpu6510_CLI();
+	cpu6510_CLC();
+	cpu6510_RTS();
+}
+
+inline void do_highlevel() {
+	if (reg_pc == 0xe5cd + 1) kernal_e5cd();
+	else if (reg_pc == 0xe9d4 + 1) kernal_e9d4();
+	else if (reg_pc == 0xed40 + 1) kernal_ed40();
+	else if (reg_pc == 0xee13 + 1) kernal_ee13();
+	else cpu6510_JAM();
+}