1385 lines
133 KiB
C
1385 lines
133 KiB
C
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#include <stdint.h>
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#include <avr/pgmspace.h>
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//extern void printhex(uint16_t val);
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//extern void serout(uint8_t value);
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extern uint8_t RAM[];
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#define NULL (void *) 0
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#define RAM_SIZE 832
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#define FLAG_CARRY 0x01
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#define FLAG_ZERO 0x02
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#define FLAG_INTERRUPT 0x04
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#define FLAG_DECIMAL 0x08
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#define FLAG_BREAK 0x10
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#define FLAG_CONSTANT 0x20
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#define FLAG_OVERFLOW 0x40
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#define FLAG_SIGN 0x80
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#define BASE_STACK 0x100
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#define saveaccum(n) a = (uint8_t)((n) & 0x00FF)
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//flag modifier macros
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#define setcarry() cpustatus |= FLAG_CARRY
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#define clearcarry() cpustatus &= (~FLAG_CARRY)
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#define setzero() cpustatus |= FLAG_ZERO
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#define clearzero() cpustatus &= (~FLAG_ZERO)
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#define setinterrupt() cpustatus |= FLAG_INTERRUPT
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#define clearinterrupt() cpustatus &= (~FLAG_INTERRUPT)
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#define setdecimal() cpustatus |= FLAG_DECIMAL
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#define cleardecimal() cpustatus &= (~FLAG_DECIMAL)
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#define setoverflow() cpustatus |= FLAG_OVERFLOW
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#define clearoverflow() cpustatus &= (~FLAG_OVERFLOW)
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#define setsign() cpustatus |= FLAG_SIGN
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#define clearsign() cpustatus &= (~FLAG_SIGN)
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//flag calculation macros
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#define zerocalc(n) { if ((n) & 0x00FF) clearzero(); else setzero(); }
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#define signcalc(n) { if ((n) & 0x0080) setsign(); else clearsign(); }
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#define carrycalc(n) { if ((n) & 0xFF00) setcarry(); else clearcarry(); }
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#define overflowcalc(n, m, o) { if (((n) ^ (uint16_t)(m)) & ((n) ^ (o)) & 0x0080) setoverflow(); else clearoverflow(); }
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//6502 CPU registers
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uint16_t pc;
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uint8_t sp, a, x, y, cpustatus;
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//helper variables
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//uint32_t instructions = 0; //keep track of total instructions executed
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//int32_t clockticks6502 = 0, clockgoal6502 = 0;
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uint16_t oldpc, ea, reladdr, value, result;
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uint8_t opcode, oldcpustatus, useaccum;
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uint8_t RAM[RAM_SIZE];
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const unsigned char BIOS[16384] PROGMEM = { 0x78 , 0xE3 , 0x67 , 0xE4 , 0x43 , 0x42 , 0x4D , 0x42 , 0x41 , 0x53 , 0x49 , 0x43 , 0x30 , 0xC8 , 0x41 , 0xC7 , 0x1D , 0xCD , 0xF7 , 0xC8 , 0xA4 , 0xCB , 0xBE , 0xCB , 0x80 , 0xD0 , 0x5 , 0xCC , 0xA4 , 0xC9 , 0x9F , 0xC8 , 0x70 , 0xC8 , 0x27 , 0xC9 , 0x1C , 0xC8 , 0x82 , 0xC8 , 0xD1 , 0xC8 , 0x3A , 0xC9 , 0x2E , 0xC8 , 0x4A , 0xC9 , 0x2C , 0xD8 , 0x64 , 0xE1 , 0x52 , 0xE1 , 0x61 , 0xE1 , 0xB2 , 0xD3 , 0x23 , 0xD8 , 0x7F , 0xCA , 0x9F , 0xCA , 0x56 , 0xC8 , 0x9B , 0xC6 , 0x5D , 0xC6 , 0x85 , 0xCA , 0x26 , 0xE1 , 0xBA , 0xE1 , 0xC3 , 0xE1 , 0x7A , 0xCB , 0x41 , 0xC6 , 0x39 , 0xDC , 0xCC , 0xDC , 0x58 , 0xDC , 0x0 , 0x0 , 0x7D , 0xD3 , 0x9E , 0xD3 , 0x71 , 0xDF , 0x94 , 0xE0 , 0xEA , 0xD9 , 0xED , 0xDF , 0x61 , 0xE2 , 0x68 , 0xE2 , 0xB1 , 0xE2 , 0xB , 0xE3 , 0xD , 0xD8 , 0x7C , 0xD7 , 0x65 , 0xD4 , 0xAD , 0xD7 , 0x8B , 0xD7 , 0xEC , 0xD6 , 0x0 , 0xD7 , 0x2C , 0xD7 , 0x37 , 0xD7 , 0x79 , 0x69 , 0xD8 , 0x79 , 0x52 , 0xD8 , 0x7B , 0x2A , 0xDA , 0x7B , 0x11 , 0xDB , 0x7F , 0x7A , 0xDF , 0x50 , 0xE8 , 0xCF , 0x46 , 0xE5 , 0xCF , 0x7D , 0xB3 , 0xDF , 0x5A , 0xD3 , 0xCE , 0x64 , 0x15 , 0xD0 , 0x45 , 0x4E , 0xC4 , 0x46 , 0x4F , 0xD2 , 0x4E , 0x45 , 0x58 , 0xD4 , 0x44 , 0x41 , 0x54 , 0xC1 , 0x49 , 0x4E , 0x50 , 0x55 , 0x54 , 0xA3 , 0x49 , 0x4E , 0x50 , 0x55 , 0xD4 , 0x44 , 0x49 , 0xCD , 0x52 , 0x45 , 0x41 , 0xC4 , 0x4C , 0x45 , 0xD4 , 0x47 , 0x4F , 0x54 , 0xCF , 0x52 , 0x55 , 0xCE , 0x49 , 0xC6 , 0x52 , 0x45 , 0x53 , 0x54 , 0x4F , 0x52 , 0xC5 , 0x47 , 0x4F , 0x53 , 0x55 , 0xC2 , 0x52 , 0x45 , 0x54 , 0x55 , 0x52 , 0xCE , 0x52 , 0x45 , 0xCD , 0x53 , 0x54 , 0x4F , 0xD0 , 0x4F , 0xCE , 0x57 , 0x41 , 0x49 , 0xD4 , 0x4C , 0x4F , 0x41 , 0xC4 , 0x53 , 0x41 , 0x56 , 0xC5 , 0x56 , 0x45 , 0x52 , 0x49 , 0x46 , 0xD9 , 0x44 , 0x45 , 0xC6 , 0x50 , 0x4F , 0x4B , 0xC5 , 0x50 , 0x52 , 0x49 , 0x4E , 0x54 , 0xA3 , 0x50 , 0x52 , 0x49 , 0x4E , 0xD4 , 0x43 , 0x4F , 0x4E , 0xD4 , 0x4C , 0x49 , 0x53 , 0xD4 , 0x43 , 0x4C , 0xD2 , 0x43 , 0x4D , 0xC4 , 0x53 , 0x59 , 0xD3 , 0x4F , 0x50 , 0x45 , 0xCE , 0x43 , 0x4C , 0x4F , 0x53 , 0xC5 , 0x47 , 0x45 , 0xD4 , 0x4E , 0x45 , 0xD7 , 0x54 , 0x41 , 0x42 , 0xA8 , 0x54 , 0xCF , 0x46 , 0xCE , 0x53 , 0x50 , 0x43 , 0xA8 , 0x54 , 0x48 , 0x45 , 0xCE , 0x4E , 0x4F , 0xD4 , 0x53 , 0x54 , 0x45 , 0xD0 , 0xAB , 0xAD , 0xAA , 0xAF , 0xDE , 0x41 , 0x4E , 0xC4 , 0x4F , 0xD2 , 0xBE , 0xBD , 0xBC , 0x53 , 0x47 , 0xCE , 0x49 , 0x4E , 0xD4 , 0x41 , 0x42 , 0xD3 , 0x55 , 0x53 , 0xD2 , 0x46 , 0x52 , 0xC5 , 0x50 , 0x4F , 0xD3 , 0x53 , 0x51 , 0xD2 , 0x52 , 0x4E , 0xC4 , 0x4C , 0x4F , 0xC7 , 0x45 , 0x58 , 0xD0 , 0x43 , 0x4F , 0xD3 , 0x53 , 0x49 , 0xCE , 0x54 , 0x41 , 0xCE , 0x41 , 0x54 , 0xCE , 0x50 , 0x45 , 0x45 , 0xCB , 0x4C , 0x45 , 0xCE , 0x53 , 0x54 , 0x52 , 0xA4 , 0x56 , 0x41 , 0xCC , 0x41 , 0x53 , 0xC3 , 0x43 , 0x48 , 0x52 , 0xA4 , 0x4C , 0x45 , 0x46 , 0x54 , 0xA4 , 0x52 , 0x49 , 0x47 , 0x48 , 0x54 , 0xA4 , 0x4D , 0x49 , 0x44 , 0xA4 , 0x47 , 0xCF , 0x0 , 0x54 , 0x4F , 0x4F , 0x20 , 0x4D , 0x41 , 0x4E , 0x59 , 0x20 , 0x46 , 0x49 , 0x4C , 0x45 , 0xD3 , 0x46 , 0x49 , 0x4C , 0x45 , 0x20 , 0x4F , 0x50 , 0x45 , 0xCE , 0x46 , 0x49 , 0x4C , 0x45 , 0x20 , 0x4E , 0x4F , 0x54 , 0x20 , 0x4F , 0x50 , 0x45 , 0xCE , 0x46 , 0x49 , 0x4C , 0x45 , 0x20 , 0x4E , 0x4F , 0x54 , 0x20 , 0x46 , 0x4F , 0x55 , 0x4E , 0xC4 , 0x44 , 0x45 , 0x56 , 0x49 , 0x43 , 0x45 , 0x20 , 0x4E , 0x4F , 0x54 , 0x20 , 0x50 , 0x52 , 0x45 , 0x53 , 0x45 , 0x4E , 0xD4 , 0x4E , 0x4F , 0x54 , 0x20 , 0x49 , 0x4E , 0x50 , 0x55 , 0x54 , 0x20 , 0x46 , 0x49 , 0x4C , 0xC5 , 0x4E , 0x4F , 0x54 , 0x20 , 0x4F , 0x55 , 0x54 , 0x50 , 0x55 , 0x54 , 0x20 , 0x46 , 0x49 , 0x4C , 0xC5 , 0x4D , 0x49 , 0x53 , 0x53 , 0x49 , 0x4E , 0x47 , 0x20 , 0x46 , 0x49 , 0x4C , 0x45 , 0x20 , 0x4E , 0x41 , 0x4D , 0xC5 , 0x49 , 0x4C , 0x4C , 0x45 , 0x47 , 0x41 , 0x4C , 0x20 , 0x44 , 0x45 , 0x56 , 0x49 , 0x43 , 0x45 , 0x20 , 0x4E , 0x55 , 0x4D , 0x42 , 0x45 , 0xD2 , 0x4E , 0x45 , 0x58 , 0x54 , 0x20 , 0x57 , 0x49 , 0x54 , 0x48 , 0x4F , 0x55 , 0x54 , 0x20 , 0x46 , 0x4F , 0xD2 , 0x53 , 0x59 , 0x4E , 0x54 , 0x41 , 0xD8 , 0x52 , 0x45 , 0x54 , 0x55 , 0x52 , 0x4E , 0x20 , 0x57 , 0x49
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};
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uint8_t read6502(uint16_t address) {
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if (address >= 0xC000) {
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return(pgm_read_byte_near(BIOS + (address - 0xC000)));
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}
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if (address < RAM_SIZE) return(RAM[address]);
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return(readEEPROM(address) );
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}
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void write6502(uint16_t address, uint8_t value) {
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if (address < RAM_SIZE) {
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RAM[address] = value;
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}
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else {
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writeEEPROM(address, value );
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}
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}
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//a few general functions used by various other functions
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void push16(uint16_t pushval) {
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write6502(BASE_STACK + sp, (pushval >> 8) & 0xFF);
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write6502(BASE_STACK + ((sp - 1) & 0xFF), pushval & 0xFF);
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sp -= 2;
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}
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void push8(uint8_t pushval) {
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write6502(BASE_STACK + sp--, pushval);
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}
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uint16_t pull16() {
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uint16_t temp16;
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temp16 = read6502(BASE_STACK + ((sp + 1) & 0xFF)) | ((uint16_t)read6502(BASE_STACK + ((sp + 2) & 0xFF)) << 8);
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sp += 2;
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return(temp16);
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}
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uint8_t pull8() {
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return (read6502(BASE_STACK + ++sp));
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}
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void reset6502() {
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pc = (uint16_t)read6502(0xFFFC) | ((uint16_t)read6502(0xFFFD) << 8);
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a = 0;
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x = 0;
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y = 0;
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sp = 0xFD;
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cpustatus |= FLAG_CONSTANT;
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}
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//addressing mode functions, calculates effective addresses
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void imp() { //implied
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}
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void acc() { //accumulator
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useaccum = 1;
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}
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void imm() { //immediate
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ea = pc++;
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}
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void zp() { //zero-page
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ea = (uint16_t)read6502((uint16_t)pc++);
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}
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void zpx() { //zero-page,X
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ea = ((uint16_t)read6502((uint16_t)pc++) + (uint16_t)x) & 0xFF; //zero-page wraparound
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}
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void zpy() { //zero-page,Y
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ea = ((uint16_t)read6502((uint16_t)pc++) + (uint16_t)y) & 0xFF; //zero-page wraparound
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}
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void rel() { //relative for branch ops (8-bit immediate value, sign-extended)
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reladdr = (uint16_t)read6502(pc++);
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if (reladdr & 0x80) reladdr |= 0xFF00;
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}
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void abso() { //absolute
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ea = (uint16_t)read6502(pc) | ((uint16_t)read6502(pc+1) << 8);
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pc += 2;
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}
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void absx() { //absolute,X
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uint16_t startpage;
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ea = ((uint16_t)read6502(pc) | ((uint16_t)read6502(pc+1) << 8));
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startpage = ea & 0xFF00;
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ea += (uint16_t)x;
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pc += 2;
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}
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void absy() { //absolute,Y
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uint16_t startpage;
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ea = ((uint16_t)read6502(pc) | ((uint16_t)read6502(pc+1) << 8));
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startpage = ea & 0xFF00;
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ea += (uint16_t)y;
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pc += 2;
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}
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void ind() { //indirect
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uint16_t eahelp, eahelp2;
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eahelp = (uint16_t)read6502(pc) | (uint16_t)((uint16_t)read6502(pc+1) << 8);
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eahelp2 = (eahelp & 0xFF00) | ((eahelp + 1) & 0x00FF); //replicate 6502 page-boundary wraparound bug
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ea = (uint16_t)read6502(eahelp) | ((uint16_t)read6502(eahelp2) << 8);
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pc += 2;
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}
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void indx() { // (indirect,X)
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uint16_t eahelp;
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eahelp = (uint16_t)(((uint16_t)read6502(pc++) + (uint16_t)x) & 0xFF); //zero-page wraparound for table pointer
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ea = (uint16_t)read6502(eahelp & 0x00FF) | ((uint16_t)read6502((eahelp+1) & 0x00FF) << 8);
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}
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void indy() { // (indirect),Y
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uint16_t eahelp, eahelp2, startpage;
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eahelp = (uint16_t)read6502(pc++);
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eahelp2 = (eahelp & 0xFF00) | ((eahelp + 1) & 0x00FF); //zero-page wraparound
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ea = (uint16_t)read6502(eahelp) | ((uint16_t)read6502(eahelp2) << 8);
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startpage = ea & 0xFF00;
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ea += (uint16_t)y;
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}
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static uint16_t getvalue() {
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if (useaccum) return((uint16_t)a);
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else return((uint16_t)read6502(ea));
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}
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static uint16_t getvalue16() {
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return((uint16_t)read6502(ea) | ((uint16_t)read6502(ea+1) << 8));
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}
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void putvalue(uint16_t saveval) {
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if (useaccum) a = (uint8_t)(saveval & 0x00FF);
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else write6502(ea, (saveval & 0x00FF));
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}
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//instruction handler functions
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void adc() {
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value = getvalue();
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result = (uint16_t)a + value + (uint16_t)(cpustatus & FLAG_CARRY);
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carrycalc(result);
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zerocalc(result);
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overflowcalc(result, a, value);
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signcalc(result);
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#ifndef NES_CPU
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if (cpustatus & FLAG_DECIMAL) {
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clearcarry();
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if ((a & 0x0F) > 0x09) {
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a += 0x06;
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}
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if ((a & 0xF0) > 0x90) {
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a += 0x60;
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setcarry();
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}
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//clockticks6502++;
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}
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#endif
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saveaccum(result);
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}
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void op_and() {
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value = getvalue();
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result = (uint16_t)a & value;
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zerocalc(result);
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signcalc(result);
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saveaccum(result);
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}
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void asl() {
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value = getvalue();
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result = value << 1;
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carrycalc(result);
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zerocalc(result);
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signcalc(result);
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putvalue(result);
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}
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void bcc() {
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if ((cpustatus & FLAG_CARRY) == 0) {
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oldpc = pc;
|
||
|
|
pc += reladdr;
|
||
|
|
//if ((oldpc & 0xFF00) != (pc & 0xFF00)) clockticks6502 += 2; //check if jump crossed a page boundary
|
||
|
|
// else clockticks6502++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void bcs() {
|
||
|
|
if ((cpustatus & FLAG_CARRY) == FLAG_CARRY) {
|
||
|
|
oldpc = pc;
|
||
|
|
pc += reladdr;
|
||
|
|
//if ((oldpc & 0xFF00) != (pc & 0xFF00)) clockticks6502 += 2; //check if jump crossed a page boundary
|
||
|
|
// else clockticks6502++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void beq() {
|
||
|
|
if ((cpustatus & FLAG_ZERO) == FLAG_ZERO) {
|
||
|
|
oldpc = pc;
|
||
|
|
pc += reladdr;
|
||
|
|
//if ((oldpc & 0xFF00) != (pc & 0xFF00)) clockticks6502 += 2; //check if jump crossed a page boundary
|
||
|
|
// else clockticks6502++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void op_bit() {
|
||
|
|
value = getvalue();
|
||
|
|
result = (uint16_t)a & value;
|
||
|
|
|
||
|
|
zerocalc(result);
|
||
|
|
cpustatus = (cpustatus & 0x3F) | (uint8_t)(value & 0xC0);
|
||
|
|
}
|
||
|
|
|
||
|
|
void bmi() {
|
||
|
|
if ((cpustatus & FLAG_SIGN) == FLAG_SIGN) {
|
||
|
|
oldpc = pc;
|
||
|
|
pc += reladdr;
|
||
|
|
//if ((oldpc & 0xFF00) != (pc & 0xFF00)) clockticks6502 += 2; //check if jump crossed a page boundary
|
||
|
|
// else clockticks6502++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void bne() {
|
||
|
|
if ((cpustatus & FLAG_ZERO) == 0) {
|
||
|
|
oldpc = pc;
|
||
|
|
pc += reladdr;
|
||
|
|
//if ((oldpc & 0xFF00) != (pc & 0xFF00)) clockticks6502 += 2; //check if jump crossed a page boundary
|
||
|
|
// else clockticks6502++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void bpl() {
|
||
|
|
if ((cpustatus & FLAG_SIGN) == 0) {
|
||
|
|
oldpc = pc;
|
||
|
|
pc += reladdr;
|
||
|
|
//if ((oldpc & 0xFF00) != (pc & 0xFF00)) clockticks6502 += 2; //check if jump crossed a page boundary
|
||
|
|
// else clockticks6502++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void brk() {
|
||
|
|
pc++;
|
||
|
|
push16(pc); //push next instruction address onto stack
|
||
|
|
push8(cpustatus | FLAG_BREAK); //push CPU cpustatus to stack
|
||
|
|
setinterrupt(); //set interrupt flag
|
||
|
|
pc = (uint16_t)read6502(0xFFFE) | ((uint16_t)read6502(0xFFFF) << 8);
|
||
|
|
}
|
||
|
|
|
||
|
|
void bvc() {
|
||
|
|
if ((cpustatus & FLAG_OVERFLOW) == 0) {
|
||
|
|
oldpc = pc;
|
||
|
|
pc += reladdr;
|
||
|
|
//if ((oldpc & 0xFF00) != (pc & 0xFF00)) clockticks6502 += 2; //check if jump crossed a page boundary
|
||
|
|
// else clockticks6502++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void bvs() {
|
||
|
|
if ((cpustatus & FLAG_OVERFLOW) == FLAG_OVERFLOW) {
|
||
|
|
oldpc = pc;
|
||
|
|
pc += reladdr;
|
||
|
|
//if ((oldpc & 0xFF00) != (pc & 0xFF00)) clockticks6502 += 2; //check if jump crossed a page boundary
|
||
|
|
// else clockticks6502++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void clc() {
|
||
|
|
clearcarry();
|
||
|
|
}
|
||
|
|
|
||
|
|
void cld() {
|
||
|
|
cleardecimal();
|
||
|
|
}
|
||
|
|
|
||
|
|
void cli() {
|
||
|
|
clearinterrupt();
|
||
|
|
}
|
||
|
|
|
||
|
|
void clv() {
|
||
|
|
clearoverflow();
|
||
|
|
}
|
||
|
|
|
||
|
|
void cmp() {
|
||
|
|
value = getvalue();
|
||
|
|
result = (uint16_t)a - value;
|
||
|
|
|
||
|
|
if (a >= (uint8_t)(value & 0x00FF)) setcarry();
|
||
|
|
else clearcarry();
|
||
|
|
if (a == (uint8_t)(value & 0x00FF)) setzero();
|
||
|
|
else clearzero();
|
||
|
|
signcalc(result);
|
||
|
|
}
|
||
|
|
|
||
|
|
void cpx() {
|
||
|
|
value = getvalue();
|
||
|
|
result = (uint16_t)x - value;
|
||
|
|
|
||
|
|
if (x >= (uint8_t)(value & 0x00FF)) setcarry();
|
||
|
|
else clearcarry();
|
||
|
|
if (x == (uint8_t)(value & 0x00FF)) setzero();
|
||
|
|
else clearzero();
|
||
|
|
signcalc(result);
|
||
|
|
}
|
||
|
|
|
||
|
|
void cpy() {
|
||
|
|
value = getvalue();
|
||
|
|
result = (uint16_t)y - value;
|
||
|
|
|
||
|
|
if (y >= (uint8_t)(value & 0x00FF)) setcarry();
|
||
|
|
else clearcarry();
|
||
|
|
if (y == (uint8_t)(value & 0x00FF)) setzero();
|
||
|
|
else clearzero();
|
||
|
|
signcalc(result);
|
||
|
|
}
|
||
|
|
|
||
|
|
void dec() {
|
||
|
|
value = getvalue();
|
||
|
|
result = value - 1;
|
||
|
|
|
||
|
|
zerocalc(result);
|
||
|
|
signcalc(result);
|
||
|
|
|
||
|
|
putvalue(result);
|
||
|
|
}
|
||
|
|
|
||
|
|
void dex() {
|
||
|
|
x--;
|
||
|
|
|
||
|
|
zerocalc(x);
|
||
|
|
signcalc(x);
|
||
|
|
}
|
||
|
|
|
||
|
|
void dey() {
|
||
|
|
y--;
|
||
|
|
|
||
|
|
zerocalc(y);
|
||
|
|
signcalc(y);
|
||
|
|
}
|
||
|
|
|
||
|
|
void eor() {
|
||
|
|
value = getvalue();
|
||
|
|
result = (uint16_t)a ^ value;
|
||
|
|
|
||
|
|
zerocalc(result);
|
||
|
|
signcalc(result);
|
||
|
|
|
||
|
|
saveaccum(result);
|
||
|
|
}
|
||
|
|
|
||
|
|
void inc() {
|
||
|
|
value = getvalue();
|
||
|
|
result = value + 1;
|
||
|
|
|
||
|
|
zerocalc(result);
|
||
|
|
signcalc(result);
|
||
|
|
|
||
|
|
putvalue(result);
|
||
|
|
}
|
||
|
|
|
||
|
|
void inx() {
|
||
|
|
x++;
|
||
|
|
|
||
|
|
zerocalc(x);
|
||
|
|
signcalc(x);
|
||
|
|
}
|
||
|
|
|
||
|
|
void iny() {
|
||
|
|
y++;
|
||
|
|
|
||
|
|
zerocalc(y);
|
||
|
|
signcalc(y);
|
||
|
|
}
|
||
|
|
|
||
|
|
void jmp() {
|
||
|
|
pc = ea;
|
||
|
|
}
|
||
|
|
|
||
|
|
void jsr() {
|
||
|
|
push16(pc - 1);
|
||
|
|
pc = ea;
|
||
|
|
}
|
||
|
|
|
||
|
|
void lda() {
|
||
|
|
value = getvalue();
|
||
|
|
a = (uint8_t)(value & 0x00FF);
|
||
|
|
|
||
|
|
zerocalc(a);
|
||
|
|
signcalc(a);
|
||
|
|
}
|
||
|
|
|
||
|
|
void ldx() {
|
||
|
|
value = getvalue();
|
||
|
|
x = (uint8_t)(value & 0x00FF);
|
||
|
|
|
||
|
|
zerocalc(x);
|
||
|
|
signcalc(x);
|
||
|
|
}
|
||
|
|
|
||
|
|
void ldy() {
|
||
|
|
value = getvalue();
|
||
|
|
y = (uint8_t)(value & 0x00FF);
|
||
|
|
|
||
|
|
zerocalc(y);
|
||
|
|
signcalc(y);
|
||
|
|
}
|
||
|
|
|
||
|
|
void lsr() {
|
||
|
|
value = getvalue();
|
||
|
|
result = value >> 1;
|
||
|
|
|
||
|
|
if (value & 1) setcarry();
|
||
|
|
else clearcarry();
|
||
|
|
zerocalc(result);
|
||
|
|
signcalc(result);
|
||
|
|
|
||
|
|
putvalue(result);
|
||
|
|
}
|
||
|
|
|
||
|
|
void nop() {
|
||
|
|
}
|
||
|
|
|
||
|
|
void ora() {
|
||
|
|
value = getvalue();
|
||
|
|
result = (uint16_t)a | value;
|
||
|
|
|
||
|
|
zerocalc(result);
|
||
|
|
signcalc(result);
|
||
|
|
|
||
|
|
saveaccum(result);
|
||
|
|
}
|
||
|
|
|
||
|
|
void pha() {
|
||
|
|
push8(a);
|
||
|
|
}
|
||
|
|
|
||
|
|
void php() {
|
||
|
|
push8(cpustatus | FLAG_BREAK);
|
||
|
|
}
|
||
|
|
|
||
|
|
void pla() {
|
||
|
|
a = pull8();
|
||
|
|
|
||
|
|
zerocalc(a);
|
||
|
|
signcalc(a);
|
||
|
|
}
|
||
|
|
|
||
|
|
void plp() {
|
||
|
|
cpustatus = pull8() | FLAG_CONSTANT;
|
||
|
|
}
|
||
|
|
|
||
|
|
void rol() {
|
||
|
|
value = getvalue();
|
||
|
|
result = (value << 1) | (cpustatus & FLAG_CARRY);
|
||
|
|
|
||
|
|
carrycalc(result);
|
||
|
|
zerocalc(result);
|
||
|
|
signcalc(result);
|
||
|
|
|
||
|
|
putvalue(result);
|
||
|
|
}
|
||
|
|
|
||
|
|
void ror() {
|
||
|
|
value = getvalue();
|
||
|
|
result = (value >> 1) | ((cpustatus & FLAG_CARRY) << 7);
|
||
|
|
|
||
|
|
if (value & 1) setcarry();
|
||
|
|
else clearcarry();
|
||
|
|
zerocalc(result);
|
||
|
|
signcalc(result);
|
||
|
|
|
||
|
|
putvalue(result);
|
||
|
|
}
|
||
|
|
|
||
|
|
void rti() {
|
||
|
|
cpustatus = pull8();
|
||
|
|
value = pull16();
|
||
|
|
pc = value;
|
||
|
|
}
|
||
|
|
|
||
|
|
void rts() {
|
||
|
|
value = pull16();
|
||
|
|
pc = value + 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
void sbc() {
|
||
|
|
value = getvalue() ^ 0x00FF;
|
||
|
|
result = (uint16_t)a + value + (uint16_t)(cpustatus & FLAG_CARRY);
|
||
|
|
|
||
|
|
carrycalc(result);
|
||
|
|
zerocalc(result);
|
||
|
|
overflowcalc(result, a, value);
|
||
|
|
signcalc(result);
|
||
|
|
|
||
|
|
#ifndef NES_CPU
|
||
|
|
if (cpustatus & FLAG_DECIMAL) {
|
||
|
|
clearcarry();
|
||
|
|
|
||
|
|
a -= 0x66;
|
||
|
|
if ((a & 0x0F) > 0x09) {
|
||
|
|
a += 0x06;
|
||
|
|
}
|
||
|
|
if ((a & 0xF0) > 0x90) {
|
||
|
|
a += 0x60;
|
||
|
|
setcarry();
|
||
|
|
}
|
||
|
|
|
||
|
|
//clockticks6502++;
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
saveaccum(result);
|
||
|
|
}
|
||
|
|
|
||
|
|
void sec() {
|
||
|
|
setcarry();
|
||
|
|
}
|
||
|
|
|
||
|
|
void sed() {
|
||
|
|
setdecimal();
|
||
|
|
}
|
||
|
|
|
||
|
|
void sei() {
|
||
|
|
setinterrupt();
|
||
|
|
}
|
||
|
|
|
||
|
|
void sta() {
|
||
|
|
putvalue(a);
|
||
|
|
}
|
||
|
|
|
||
|
|
void stx() {
|
||
|
|
putvalue(x);
|
||
|
|
}
|
||
|
|
|
||
|
|
void sty() {
|
||
|
|
putvalue(y);
|
||
|
|
}
|
||
|
|
|
||
|
|
void tax() {
|
||
|
|
x = a;
|
||
|
|
|
||
|
|
zerocalc(x);
|
||
|
|
signcalc(x);
|
||
|
|
}
|
||
|
|
|
||
|
|
void tay() {
|
||
|
|
y = a;
|
||
|
|
|
||
|
|
zerocalc(y);
|
||
|
|
signcalc(y);
|
||
|
|
}
|
||
|
|
|
||
|
|
void tsx() {
|
||
|
|
x = sp;
|
||
|
|
|
||
|
|
zerocalc(x);
|
||
|
|
signcalc(x);
|
||
|
|
}
|
||
|
|
|
||
|
|
void txa() {
|
||
|
|
a = x;
|
||
|
|
|
||
|
|
zerocalc(a);
|
||
|
|
signcalc(a);
|
||
|
|
}
|
||
|
|
|
||
|
|
void txs() {
|
||
|
|
sp = x;
|
||
|
|
}
|
||
|
|
|
||
|
|
void tya() {
|
||
|
|
a = y;
|
||
|
|
|
||
|
|
zerocalc(a);
|
||
|
|
signcalc(a);
|
||
|
|
}
|
||
|
|
|
||
|
|
//undocumented instructions
|
||
|
|
#ifdef UNDOCUMENTED
|
||
|
|
void lax() {
|
||
|
|
lda();
|
||
|
|
ldx();
|
||
|
|
}
|
||
|
|
|
||
|
|
void sax() {
|
||
|
|
sta();
|
||
|
|
stx();
|
||
|
|
putvalue(a & x);
|
||
|
|
}
|
||
|
|
|
||
|
|
void dcp() {
|
||
|
|
dec();
|
||
|
|
cmp();
|
||
|
|
}
|
||
|
|
|
||
|
|
void isb() {
|
||
|
|
inc();
|
||
|
|
sbc();
|
||
|
|
}
|
||
|
|
|
||
|
|
void slo() {
|
||
|
|
asl();
|
||
|
|
ora();
|
||
|
|
}
|
||
|
|
|
||
|
|
void rla() {
|
||
|
|
rol();
|
||
|
|
op_and();
|
||
|
|
}
|
||
|
|
|
||
|
|
void sre() {
|
||
|
|
lsr();
|
||
|
|
eor();
|
||
|
|
}
|
||
|
|
|
||
|
|
void rra() {
|
||
|
|
ror();
|
||
|
|
adc();
|
||
|
|
}
|
||
|
|
#else
|
||
|
|
#define lax nop
|
||
|
|
#define sax nop
|
||
|
|
#define dcp nop
|
||
|
|
#define isb nop
|
||
|
|
#define slo nop
|
||
|
|
#define rla nop
|
||
|
|
#define sre nop
|
||
|
|
#define rra nop
|
||
|
|
#endif
|
||
|
|
|
||
|
|
|
||
|
|
void nmi6502() {
|
||
|
|
push16(pc);
|
||
|
|
push8(cpustatus);
|
||
|
|
cpustatus |= FLAG_INTERRUPT;
|
||
|
|
pc = (uint16_t)read6502(0xFFFA) | ((uint16_t)read6502(0xFFFB) << 8);
|
||
|
|
}
|
||
|
|
|
||
|
|
void irq6502() {
|
||
|
|
push16(pc);
|
||
|
|
push8(cpustatus);
|
||
|
|
cpustatus |= FLAG_INTERRUPT;
|
||
|
|
pc = (uint16_t)read6502(0xFFFE) | ((uint16_t)read6502(0xFFFF) << 8);
|
||
|
|
}
|
||
|
|
|
||
|
|
#ifdef USE_TIMING
|
||
|
|
prog_char ticktable[256] PROGMEM = {
|
||
|
|
/* | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | A | B | C | D | E | F | */
|
||
|
|
/* 0 */ 7, 6, 2, 8, 3, 3, 5, 5, 3, 2, 2, 2, 4, 4, 6, 6, /* 0 */
|
||
|
|
/* 1 */ 2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 4, 4, 7, 7, /* 1 */
|
||
|
|
/* 2 */ 6, 6, 2, 8, 3, 3, 5, 5, 4, 2, 2, 2, 4, 4, 6, 6, /* 2 */
|
||
|
|
/* 3 */ 2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 4, 4, 7, 7, /* 3 */
|
||
|
|
/* 4 */ 6, 6, 2, 8, 3, 3, 5, 5, 3, 2, 2, 2, 3, 4, 6, 6, /* 4 */
|
||
|
|
/* 5 */ 2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 4, 4, 7, 7, /* 5 */
|
||
|
|
/* 6 */ 6, 6, 2, 8, 3, 3, 5, 5, 4, 2, 2, 2, 5, 4, 6, 6, /* 6 */
|
||
|
|
/* 7 */ 2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 4, 4, 7, 7, /* 7 */
|
||
|
|
/* 8 */ 2, 6, 2, 6, 3, 3, 3, 3, 2, 2, 2, 2, 4, 4, 4, 4, /* 8 */
|
||
|
|
/* 9 */ 2, 6, 2, 6, 4, 4, 4, 4, 2, 5, 2, 5, 5, 5, 5, 5, /* 9 */
|
||
|
|
/* A */ 2, 6, 2, 6, 3, 3, 3, 3, 2, 2, 2, 2, 4, 4, 4, 4, /* A */
|
||
|
|
/* B */ 2, 5, 2, 5, 4, 4, 4, 4, 2, 4, 2, 4, 4, 4, 4, 4, /* B */
|
||
|
|
/* C */ 2, 6, 2, 8, 3, 3, 5, 5, 2, 2, 2, 2, 4, 4, 6, 6, /* C */
|
||
|
|
/* D */ 2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 4, 4, 7, 7, /* D */
|
||
|
|
/* E */ 2, 6, 2, 8, 3, 3, 5, 5, 2, 2, 2, 2, 4, 4, 6, 6, /* E */
|
||
|
|
/* F */ 2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 4, 4, 7, 7 /* F */
|
||
|
|
};
|
||
|
|
#endif
|
||
|
|
|
||
|
|
void exec6502() {
|
||
|
|
#ifdef USE_TIMING
|
||
|
|
clockgoal6502 += tickcount;
|
||
|
|
|
||
|
|
while (clockgoal6502 > 0) {
|
||
|
|
#else
|
||
|
|
//while (tickcount--) {
|
||
|
|
#endif
|
||
|
|
opcode = read6502(pc++);
|
||
|
|
cpustatus |= FLAG_CONSTANT;
|
||
|
|
|
||
|
|
useaccum = 0;
|
||
|
|
|
||
|
|
switch (opcode) {
|
||
|
|
case 0x0:
|
||
|
|
imp();
|
||
|
|
brk();
|
||
|
|
break;
|
||
|
|
case 0x1:
|
||
|
|
indx();
|
||
|
|
ora();
|
||
|
|
break;
|
||
|
|
case 0x5:
|
||
|
|
zp();
|
||
|
|
ora();
|
||
|
|
break;
|
||
|
|
case 0x6:
|
||
|
|
zp();
|
||
|
|
asl();
|
||
|
|
break;
|
||
|
|
case 0x8:
|
||
|
|
imp();
|
||
|
|
php();
|
||
|
|
break;
|
||
|
|
case 0x9:
|
||
|
|
imm();
|
||
|
|
ora();
|
||
|
|
break;
|
||
|
|
case 0xA:
|
||
|
|
acc();
|
||
|
|
asl();
|
||
|
|
break;
|
||
|
|
case 0xD:
|
||
|
|
abso();
|
||
|
|
ora();
|
||
|
|
break;
|
||
|
|
case 0xE:
|
||
|
|
abso();
|
||
|
|
asl();
|
||
|
|
break;
|
||
|
|
case 0x10:
|
||
|
|
rel();
|
||
|
|
bpl();
|
||
|
|
break;
|
||
|
|
case 0x11:
|
||
|
|
indy();
|
||
|
|
ora();
|
||
|
|
break;
|
||
|
|
case 0x15:
|
||
|
|
zpx();
|
||
|
|
ora();
|
||
|
|
break;
|
||
|
|
case 0x16:
|
||
|
|
zpx();
|
||
|
|
asl();
|
||
|
|
break;
|
||
|
|
case 0x18:
|
||
|
|
imp();
|
||
|
|
clc();
|
||
|
|
break;
|
||
|
|
case 0x19:
|
||
|
|
absy();
|
||
|
|
ora();
|
||
|
|
break;
|
||
|
|
case 0x1D:
|
||
|
|
absx();
|
||
|
|
ora();
|
||
|
|
break;
|
||
|
|
case 0x1E:
|
||
|
|
absx();
|
||
|
|
asl();
|
||
|
|
break;
|
||
|
|
case 0x20:
|
||
|
|
abso();
|
||
|
|
jsr();
|
||
|
|
break;
|
||
|
|
case 0x21:
|
||
|
|
indx();
|
||
|
|
op_and();
|
||
|
|
break;
|
||
|
|
case 0x24:
|
||
|
|
zp();
|
||
|
|
op_bit();
|
||
|
|
break;
|
||
|
|
case 0x25:
|
||
|
|
zp();
|
||
|
|
op_and();
|
||
|
|
break;
|
||
|
|
case 0x26:
|
||
|
|
zp();
|
||
|
|
rol();
|
||
|
|
break;
|
||
|
|
case 0x28:
|
||
|
|
imp();
|
||
|
|
plp();
|
||
|
|
break;
|
||
|
|
case 0x29:
|
||
|
|
imm();
|
||
|
|
op_and();
|
||
|
|
break;
|
||
|
|
case 0x2A:
|
||
|
|
acc();
|
||
|
|
rol();
|
||
|
|
break;
|
||
|
|
case 0x2C:
|
||
|
|
abso();
|
||
|
|
op_bit();
|
||
|
|
break;
|
||
|
|
case 0x2D:
|
||
|
|
abso();
|
||
|
|
op_and();
|
||
|
|
break;
|
||
|
|
case 0x2E:
|
||
|
|
abso();
|
||
|
|
rol();
|
||
|
|
break;
|
||
|
|
case 0x30:
|
||
|
|
rel();
|
||
|
|
bmi();
|
||
|
|
break;
|
||
|
|
case 0x31:
|
||
|
|
indy();
|
||
|
|
op_and();
|
||
|
|
break;
|
||
|
|
case 0x35:
|
||
|
|
zpx();
|
||
|
|
op_and();
|
||
|
|
break;
|
||
|
|
case 0x36:
|
||
|
|
zpx();
|
||
|
|
rol();
|
||
|
|
break;
|
||
|
|
case 0x38:
|
||
|
|
imp();
|
||
|
|
sec();
|
||
|
|
break;
|
||
|
|
case 0x39:
|
||
|
|
absy();
|
||
|
|
op_and();
|
||
|
|
break;
|
||
|
|
case 0x3D:
|
||
|
|
absx();
|
||
|
|
op_and();
|
||
|
|
break;
|
||
|
|
case 0x3E:
|
||
|
|
absx();
|
||
|
|
rol();
|
||
|
|
break;
|
||
|
|
case 0x40:
|
||
|
|
imp();
|
||
|
|
rti();
|
||
|
|
break;
|
||
|
|
case 0x41:
|
||
|
|
indx();
|
||
|
|
eor();
|
||
|
|
break;
|
||
|
|
case 0x45:
|
||
|
|
zp();
|
||
|
|
eor();
|
||
|
|
break;
|
||
|
|
case 0x46:
|
||
|
|
zp();
|
||
|
|
lsr();
|
||
|
|
break;
|
||
|
|
case 0x48:
|
||
|
|
imp();
|
||
|
|
pha();
|
||
|
|
break;
|
||
|
|
case 0x49:
|
||
|
|
imm();
|
||
|
|
eor();
|
||
|
|
break;
|
||
|
|
case 0x4A:
|
||
|
|
acc();
|
||
|
|
lsr();
|
||
|
|
break;
|
||
|
|
case 0x4C:
|
||
|
|
abso();
|
||
|
|
jmp();
|
||
|
|
break;
|
||
|
|
case 0x4D:
|
||
|
|
abso();
|
||
|
|
eor();
|
||
|
|
break;
|
||
|
|
case 0x4E:
|
||
|
|
abso();
|
||
|
|
lsr();
|
||
|
|
break;
|
||
|
|
case 0x50:
|
||
|
|
rel();
|
||
|
|
bvc();
|
||
|
|
break;
|
||
|
|
case 0x51:
|
||
|
|
indy();
|
||
|
|
eor();
|
||
|
|
break;
|
||
|
|
case 0x55:
|
||
|
|
zpx();
|
||
|
|
eor();
|
||
|
|
break;
|
||
|
|
case 0x56:
|
||
|
|
zpx();
|
||
|
|
lsr();
|
||
|
|
break;
|
||
|
|
case 0x58:
|
||
|
|
imp();
|
||
|
|
cli();
|
||
|
|
break;
|
||
|
|
case 0x59:
|
||
|
|
absy();
|
||
|
|
eor();
|
||
|
|
break;
|
||
|
|
case 0x5D:
|
||
|
|
absx();
|
||
|
|
eor();
|
||
|
|
break;
|
||
|
|
case 0x5E:
|
||
|
|
absx();
|
||
|
|
lsr();
|
||
|
|
break;
|
||
|
|
case 0x60:
|
||
|
|
imp();
|
||
|
|
rts();
|
||
|
|
break;
|
||
|
|
case 0x61:
|
||
|
|
indx();
|
||
|
|
adc();
|
||
|
|
break;
|
||
|
|
case 0x65:
|
||
|
|
zp();
|
||
|
|
adc();
|
||
|
|
break;
|
||
|
|
case 0x66:
|
||
|
|
zp();
|
||
|
|
ror();
|
||
|
|
break;
|
||
|
|
case 0x68:
|
||
|
|
imp();
|
||
|
|
pla();
|
||
|
|
break;
|
||
|
|
case 0x69:
|
||
|
|
imm();
|
||
|
|
adc();
|
||
|
|
break;
|
||
|
|
case 0x6A:
|
||
|
|
acc();
|
||
|
|
ror();
|
||
|
|
break;
|
||
|
|
case 0x6C:
|
||
|
|
ind();
|
||
|
|
jmp();
|
||
|
|
break;
|
||
|
|
case 0x6D:
|
||
|
|
abso();
|
||
|
|
adc();
|
||
|
|
break;
|
||
|
|
case 0x6E:
|
||
|
|
abso();
|
||
|
|
ror();
|
||
|
|
break;
|
||
|
|
case 0x70:
|
||
|
|
rel();
|
||
|
|
bvs();
|
||
|
|
break;
|
||
|
|
case 0x71:
|
||
|
|
indy();
|
||
|
|
adc();
|
||
|
|
break;
|
||
|
|
case 0x75:
|
||
|
|
zpx();
|
||
|
|
adc();
|
||
|
|
break;
|
||
|
|
case 0x76:
|
||
|
|
zpx();
|
||
|
|
ror();
|
||
|
|
break;
|
||
|
|
case 0x78:
|
||
|
|
imp();
|
||
|
|
sei();
|
||
|
|
break;
|
||
|
|
case 0x79:
|
||
|
|
absy();
|
||
|
|
adc();
|
||
|
|
break;
|
||
|
|
case 0x7D:
|
||
|
|
absx();
|
||
|
|
adc();
|
||
|
|
break;
|
||
|
|
case 0x7E:
|
||
|
|
absx();
|
||
|
|
ror();
|
||
|
|
break;
|
||
|
|
case 0x81:
|
||
|
|
indx();
|
||
|
|
sta();
|
||
|
|
break;
|
||
|
|
case 0x84:
|
||
|
|
zp();
|
||
|
|
sty();
|
||
|
|
break;
|
||
|
|
case 0x85:
|
||
|
|
zp();
|
||
|
|
sta();
|
||
|
|
break;
|
||
|
|
case 0x86:
|
||
|
|
zp();
|
||
|
|
stx();
|
||
|
|
break;
|
||
|
|
case 0x88:
|
||
|
|
imp();
|
||
|
|
dey();
|
||
|
|
break;
|
||
|
|
case 0x8A:
|
||
|
|
imp();
|
||
|
|
txa();
|
||
|
|
break;
|
||
|
|
case 0x8C:
|
||
|
|
abso();
|
||
|
|
sty();
|
||
|
|
break;
|
||
|
|
case 0x8D:
|
||
|
|
abso();
|
||
|
|
sta();
|
||
|
|
break;
|
||
|
|
case 0x8E:
|
||
|
|
abso();
|
||
|
|
stx();
|
||
|
|
break;
|
||
|
|
case 0x90:
|
||
|
|
rel();
|
||
|
|
bcc();
|
||
|
|
break;
|
||
|
|
case 0x91:
|
||
|
|
indy();
|
||
|
|
sta();
|
||
|
|
break;
|
||
|
|
case 0x94:
|
||
|
|
zpx();
|
||
|
|
sty();
|
||
|
|
break;
|
||
|
|
case 0x95:
|
||
|
|
zpx();
|
||
|
|
sta();
|
||
|
|
break;
|
||
|
|
case 0x96:
|
||
|
|
zpy();
|
||
|
|
stx();
|
||
|
|
break;
|
||
|
|
case 0x98:
|
||
|
|
imp();
|
||
|
|
tya();
|
||
|
|
break;
|
||
|
|
case 0x99:
|
||
|
|
absy();
|
||
|
|
sta();
|
||
|
|
break;
|
||
|
|
case 0x9A:
|
||
|
|
imp();
|
||
|
|
txs();
|
||
|
|
break;
|
||
|
|
case 0x9D:
|
||
|
|
absx();
|
||
|
|
sta();
|
||
|
|
break;
|
||
|
|
case 0xA0:
|
||
|
|
imm();
|
||
|
|
ldy();
|
||
|
|
break;
|
||
|
|
case 0xA1:
|
||
|
|
indx();
|
||
|
|
lda();
|
||
|
|
break;
|
||
|
|
case 0xA2:
|
||
|
|
imm();
|
||
|
|
ldx();
|
||
|
|
break;
|
||
|
|
case 0xA4:
|
||
|
|
zp();
|
||
|
|
ldy();
|
||
|
|
break;
|
||
|
|
case 0xA5:
|
||
|
|
zp();
|
||
|
|
lda();
|
||
|
|
break;
|
||
|
|
case 0xA6:
|
||
|
|
zp();
|
||
|
|
ldx();
|
||
|
|
break;
|
||
|
|
case 0xA8:
|
||
|
|
imp();
|
||
|
|
tay();
|
||
|
|
break;
|
||
|
|
case 0xA9:
|
||
|
|
imm();
|
||
|
|
lda();
|
||
|
|
break;
|
||
|
|
case 0xAA:
|
||
|
|
imp();
|
||
|
|
tax();
|
||
|
|
break;
|
||
|
|
case 0xAC:
|
||
|
|
abso();
|
||
|
|
ldy();
|
||
|
|
break;
|
||
|
|
case 0xAD:
|
||
|
|
abso();
|
||
|
|
lda();
|
||
|
|
break;
|
||
|
|
case 0xAE:
|
||
|
|
abso();
|
||
|
|
ldx();
|
||
|
|
break;
|
||
|
|
case 0xB0:
|
||
|
|
rel();
|
||
|
|
bcs();
|
||
|
|
break;
|
||
|
|
case 0xB1:
|
||
|
|
indy();
|
||
|
|
lda();
|
||
|
|
break;
|
||
|
|
case 0xB4:
|
||
|
|
zpx();
|
||
|
|
ldy();
|
||
|
|
break;
|
||
|
|
case 0xB5:
|
||
|
|
zpx();
|
||
|
|
lda();
|
||
|
|
break;
|
||
|
|
case 0xB6:
|
||
|
|
zpy();
|
||
|
|
ldx();
|
||
|
|
break;
|
||
|
|
case 0xB8:
|
||
|
|
imp();
|
||
|
|
clv();
|
||
|
|
break;
|
||
|
|
case 0xB9:
|
||
|
|
absy();
|
||
|
|
lda();
|
||
|
|
break;
|
||
|
|
case 0xBA:
|
||
|
|
imp();
|
||
|
|
tsx();
|
||
|
|
break;
|
||
|
|
case 0xBC:
|
||
|
|
absx();
|
||
|
|
ldy();
|
||
|
|
break;
|
||
|
|
case 0xBD:
|
||
|
|
absx();
|
||
|
|
lda();
|
||
|
|
break;
|
||
|
|
case 0xBE:
|
||
|
|
absy();
|
||
|
|
ldx();
|
||
|
|
break;
|
||
|
|
case 0xC0:
|
||
|
|
imm();
|
||
|
|
cpy();
|
||
|
|
break;
|
||
|
|
case 0xC1:
|
||
|
|
indx();
|
||
|
|
cmp();
|
||
|
|
break;
|
||
|
|
case 0xC4:
|
||
|
|
zp();
|
||
|
|
cpy();
|
||
|
|
break;
|
||
|
|
case 0xC5:
|
||
|
|
zp();
|
||
|
|
cmp();
|
||
|
|
break;
|
||
|
|
case 0xC6:
|
||
|
|
zp();
|
||
|
|
dec();
|
||
|
|
break;
|
||
|
|
case 0xC8:
|
||
|
|
imp();
|
||
|
|
iny();
|
||
|
|
break;
|
||
|
|
case 0xC9:
|
||
|
|
imm();
|
||
|
|
cmp();
|
||
|
|
break;
|
||
|
|
case 0xCA:
|
||
|
|
imp();
|
||
|
|
dex();
|
||
|
|
break;
|
||
|
|
case 0xCC:
|
||
|
|
abso();
|
||
|
|
cpy();
|
||
|
|
break;
|
||
|
|
case 0xCD:
|
||
|
|
abso();
|
||
|
|
cmp();
|
||
|
|
break;
|
||
|
|
case 0xCE:
|
||
|
|
abso();
|
||
|
|
dec();
|
||
|
|
break;
|
||
|
|
case 0xD0:
|
||
|
|
rel();
|
||
|
|
bne();
|
||
|
|
break;
|
||
|
|
case 0xD1:
|
||
|
|
indy();
|
||
|
|
cmp();
|
||
|
|
break;
|
||
|
|
case 0xD5:
|
||
|
|
zpx();
|
||
|
|
cmp();
|
||
|
|
break;
|
||
|
|
case 0xD6:
|
||
|
|
zpx();
|
||
|
|
dec();
|
||
|
|
break;
|
||
|
|
case 0xD8:
|
||
|
|
imp();
|
||
|
|
cld();
|
||
|
|
break;
|
||
|
|
case 0xD9:
|
||
|
|
absy();
|
||
|
|
cmp();
|
||
|
|
break;
|
||
|
|
case 0xDD:
|
||
|
|
absx();
|
||
|
|
cmp();
|
||
|
|
break;
|
||
|
|
case 0xDE:
|
||
|
|
absx();
|
||
|
|
dec();
|
||
|
|
break;
|
||
|
|
case 0xE0:
|
||
|
|
imm();
|
||
|
|
cpx();
|
||
|
|
break;
|
||
|
|
case 0xE1:
|
||
|
|
indx();
|
||
|
|
sbc();
|
||
|
|
break;
|
||
|
|
case 0xE4:
|
||
|
|
zp();
|
||
|
|
cpx();
|
||
|
|
break;
|
||
|
|
case 0xE5:
|
||
|
|
zp();
|
||
|
|
sbc();
|
||
|
|
break;
|
||
|
|
case 0xE6:
|
||
|
|
zp();
|
||
|
|
inc();
|
||
|
|
break;
|
||
|
|
case 0xE8:
|
||
|
|
imp();
|
||
|
|
inx();
|
||
|
|
break;
|
||
|
|
case 0xE9:
|
||
|
|
imm();
|
||
|
|
sbc();
|
||
|
|
break;
|
||
|
|
case 0xEB:
|
||
|
|
imm();
|
||
|
|
sbc();
|
||
|
|
break;
|
||
|
|
case 0xEC:
|
||
|
|
abso();
|
||
|
|
cpx();
|
||
|
|
break;
|
||
|
|
case 0xED:
|
||
|
|
abso();
|
||
|
|
sbc();
|
||
|
|
break;
|
||
|
|
case 0xEE:
|
||
|
|
abso();
|
||
|
|
inc();
|
||
|
|
break;
|
||
|
|
case 0xF0:
|
||
|
|
rel();
|
||
|
|
beq();
|
||
|
|
break;
|
||
|
|
case 0xF1:
|
||
|
|
indy();
|
||
|
|
sbc();
|
||
|
|
break;
|
||
|
|
case 0xF5:
|
||
|
|
zpx();
|
||
|
|
sbc();
|
||
|
|
break;
|
||
|
|
case 0xF6:
|
||
|
|
zpx();
|
||
|
|
inc();
|
||
|
|
break;
|
||
|
|
case 0xF8:
|
||
|
|
imp();
|
||
|
|
sed();
|
||
|
|
break;
|
||
|
|
case 0xF9:
|
||
|
|
absy();
|
||
|
|
sbc();
|
||
|
|
break;
|
||
|
|
case 0xFD:
|
||
|
|
absx();
|
||
|
|
sbc();
|
||
|
|
break;
|
||
|
|
case 0xFE:
|
||
|
|
absx();
|
||
|
|
inc();
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
#ifdef USE_TIMING
|
||
|
|
clockgoal6502 -= (int32_t)pgm_read_byte_near(ticktable + opcode);
|
||
|
|
#endif
|
||
|
|
//instructions++;
|
||
|
|
//} //while
|
||
|
|
}
|
||
|
|
|
||
|
|
uint16_t getpc() {
|
||
|
|
return(pc);
|
||
|
|
}
|
||
|
|
|
||
|
|
uint8_t getop() {
|
||
|
|
return(opcode);
|
||
|
|
}
|
||
|
|
|
||
|
|
|