This is a2.c in view mode; [Download] [Up]
/*
* a2, an Apple II emulator in C
* (c) Copyright 1990 by Rich Skrenta
*
* Command line interface written by Tom Markson
*
* Distribution agreement:
*
* You may freely copy or redistribute this software, so long
* as there is no profit made from its use, sale, trade or
* reproduction. You may not change this copyright notice,
* and it must be included prominently in any copy made.
*
* Send emulator related mail to: skrenta@blekko.commodore.com
* skrenta@blekko.uucp
*/
#include <stdio.h>
#include "a2.h"
#define BRANCH() val = mem[Pc++]; if (val & 0x80) Pc += val - 256; else Pc += val;
#define put_status(s) stmp = s; N = stmp & 0x80; V = stmp & 0x40; B = stmp & 0x10; D = stmp & 0x08; I = stmp & 0x04; NZ = !(stmp & 0x02); C = stmp & 0x01;
extern long trace_lo, trace_hi;
extern FILE *logging_fp;
extern long phantom_location;
extern long breakpoint;
run()
{
register unsigned short ptr;
register unsigned short ptmp;
register unsigned int val;
register unsigned int tmp;
register unsigned int num;
unsigned char stmp;
int foo;
int show_flags = FALSE;
unsigned long mjhostet = 0;
do { /* while (tracing) */
if (tracing) {
if (breakpoint == Pc) {
MoveCursor(term_lines, 0);
printf("Break at $%.4X\n", Pc);
return;
}
if (phantom_location == (long) Pc)
phantom_location = -1; /* start tracing now */
if (phantom_location == -1
&& trace_lo != -1
&& (long) Pc >= trace_lo
&& (long) Pc <= trace_hi) {
diss(Pc, logging_fp);
show_flags = TRUE;
} else
show_flags = FALSE;
}
do { /* while (running) */
/* MJHOSTET HACK */
#if 1
if (!(mjhostet++ & 32767))
redraw_hgr_screen (mem + 0x2000);
#endif
switch (mem[Pc++]) {
case 0x00: /* BRK */
PCINC;
push(high(Pc));
push(low(Pc));
B = 1; /* set I flag? */
push(get_status());
Pc = join(mem[0xFFFE], mem[0xFFFF]);
break;
case 0x01: /* ORA (indirect, X) */
INDX;
A |= REFptr;
SIGN(A);
ZERO(A);
break;
case 0x02:
break;
case 0x03:
break;
case 0x04: /* TSB zero page 65C02 */
break;
case 0x05: /* ORA zero page */
A |= rZEROP;
SIGN(A);
ZERO(A);
break;
case 0x06: /* ASL zero page */
ZEROP;
val = REFzero << 1;
CARRY(val);
val &= 0xFF;
SETzero(val);
SIGN(val);
ZERO(val);
break;
case 0x07:
break;
case 0x08: /* PHP */
push(get_status());
break;
case 0x09: /* ORA immediate */
A |= REFimm;
SIGN(A);
ZERO(A);
break;
case 0x0A: /* ASL accumulator */
A = A << 1;
CARRY(A);
A &= 0xFF;
SIGN(A);
ZERO(A);
break;
case 0x0B:
break;
case 0x0C: /* TSB absolute 65C02 */
break;
case 0x0D: /* ORA absolute */
ABSOL;
A |= REFptr;
SIGN(A);
ZERO(A);
break;
case 0x0E: /* ASL absolute */
ABSOL;
val = REFptr << 1;
CARRY(val);
val &= 0xFF;
SETptr(val);
SIGN(val);
ZERO(val);
break;
case 0x0F:
break;
case 0x10: /* BPL */
if (N) {
PCINC;
} else {
BRANCH();
}
break;
case 0x11: /* ORA (indirect), Y */
INDY;
A |= REFptr;
SIGN(A);
ZERO(A);
break;
case 0x12: /* ORA (indz) 65C02 */
break;
case 0x13:
break;
case 0x14: /* TRB zero page 65C02 */
break;
case 0x15: /* ORA zero page, X */
A |= rZEROX;
SIGN(A);
ZERO(A);
break;
case 0x16: /* ASL zero page, X */
ZEROX;
val = REFzero << 1;
CARRY(val);
val &= 0xFF;
SETzero(val);
SIGN(val);
ZERO(val);
break;
case 0x17:
break;
case 0x18: /* CLC */
C = 0;
break;
case 0x19: /* ORA absolute, Y */
ABSY;
A |= REFptr;
SIGN(A);
ZERO(A);
break;
case 0x1A: /* INA 65C02 */
break;
case 0x1C: /* TRB absolute 65C02 */
break;
case 0x1D: /* ORA absolute, X */
ABSX;
A |= REFptr;
SIGN(A);
ZERO(A);
break;
case 0x1E: /* ASL absolute, X */
ABSX;
val = REFptr << 1;
CARRY(val);
val &= 0xFF;
SETptr(val);
SIGN(val);
ZERO(val);
break;
case 0x1F:
break;
case 0x20: /* JSR */
ptmp = REFimm;
ptmp |= mem[Pc] << 8;
push(high(Pc));
push(low(Pc));
Pc = ptmp;
if (jmp_tbl[Pc])
jump(jmp_tbl[Pc]);
break;
case 0x21: /* AND (indirect, X) */
INDX;
A &= REFptr;
SIGN(A);
ZERO(A);
break;
case 0x22:
break;
case 0x23:
break;
case 0x24: /* BIT zero page */
tmp = rZEROP;
ZERO(A & tmp);
N = tmp & 0x80;
V = tmp & 0x40;
break;
case 0x25: /* AND zero page */
A &= rZEROP;
SIGN(A);
ZERO(A);
break;
case 0x26: /* ROL zero page */
ZEROP;
val = REFzero;
tmp = C;
val = val << 1;
CARRY(val);
val = (val & 0xFF) | tmp;
SETzero(val);
SIGN(val);
ZERO(val);
break;
case 0x27:
break;
case 0x28: /* PLP */
put_status(pop());
break;
case 0x29: /* AND immediate */
A &= REFimm;
SIGN(A);
ZERO(A);
break;
case 0x2A: /* ROL accumulator */
tmp = C;
A = A << 1;
CARRY(A);
A = (A & 0xFF) | tmp;
SIGN(A);
ZERO(A);
break;
case 0x2B:
break;
case 0x2C: /* BIT absolute */
ABSOL;
tmp = REFptr;
ZERO(A & tmp);
N = tmp & 0x80;
V = tmp & 0x40;
break;
case 0x2D: /* AND absolute */
ABSOL;
A &= REFptr;
SIGN(A);
ZERO(A);
break;
case 0x2E: /* ROL absolute */
ABSOL;
val = REFptr;
tmp = C;
val = val << 1;
CARRY(val);
val = (val & 0xFF) | tmp;
SETptr(val);
SIGN(val);
ZERO(val);
break;
case 0x2F:
break;
case 0x30: /* BMI */
if (N) {
BRANCH();
} else{
PCINC;
}
break;
case 0x31: /* AND (indirect), Y */
INDY;
A &= REFptr;
SIGN(A);
ZERO(A);
break;
case 0x32: /* AND (indz) 65C02 */
break;
case 0x33:
break;
case 0x34: /* BIT zero page, X 65C02 */
break;
case 0x35: /* AND zero page, X */
A &= rZEROX;
SIGN(A);
ZERO(A);
break;
case 0x36: /* ROL zero page, X */
ZEROX;
val = REFzero;
tmp = C;
val = val << 1;
CARRY(val);
val = (val & 0xFF) | tmp;
SETzero(val);
SIGN(val);
ZERO(val);
break;
case 0x37:
break;
case 0x38: /* SEC */
C = 1;
break;
case 0x39: /* AND absolute, Y */
ABSY;
A &= REFptr;
SIGN(A);
ZERO(A);
break;
case 0x3A: /* DEA 65C02 */
break;
case 0x3B:
break;
case 0x3C: /* BIT absolute, X 65C02 */
break;
case 0x3D: /* AND absolute, X */
ABSX;
A &= REFptr;
SIGN(A);
ZERO(A);
break;
case 0x3E: /* ROL absolute, X */
ABSX;
val = REFptr;
tmp = C;
val = val << 1;
CARRY(val);
val = (val & 0xFF) | tmp;
SETptr(val);
SIGN(val);
ZERO(val);
break;
case 0x3F:
break;
case 0x40: /* RTI */
put_status(pop());
Pc = pop();
Pc |= pop() << 8;
break;
case 0x41: /* EOR (indirect, X) */
INDX;
A ^= REFptr;
SIGN(A);
ZERO(A);
break;
case 0x42:
break;
case 0x43:
break;
case 0x44:
break;
case 0x45: /* EOR zero page */
A ^= rZEROP;
SIGN(A);
ZERO(A);
break;
case 0x46: /* LSR zero page */
ZEROP;
tmp = REFzero;
C = (tmp & 0x01);
tmp = tmp >> 1;
SETzero(tmp);
N = 0;
ZERO(tmp);
break;
case 0x47:
break;
case 0x48: /* PHA */
push(A);
break;
case 0x49: /* EOR immediate */
A ^= REFimm;
SIGN(A);
ZERO(A);
break;
case 0x4A: /* LSR accumulator */
C = (A & 0x01);
A = A >> 1;
N = 0;
ZERO(A);
break;
case 0x4B:
break;
case 0x4C: /* JMP absolute */
ptmp = REFimm;
ptmp |= REFimm << 8;
Pc = ptmp;
if (jmp_tbl[Pc])
jump(jmp_tbl[Pc]);
break;
case 0x4D: /* EOR absolute */
ABSOL;
A ^= REFptr;
SIGN(A);
ZERO(A);
break;
case 0x4E: /* LSR absolute */
ABSOL;
tmp = REFptr;
C = (tmp & 0x01);
tmp = tmp >> 1;
SETptr(tmp);
N = 0;
ZERO(tmp);
break;
case 0x4F:
break;
case 0x50: /* BVC */
if (V) {
PCINC;
} else {
BRANCH();
}
break;
case 0x51: /* EOR (indirect), Y */
INDY;
A ^= REFptr;
SIGN(A);
ZERO(A);
break;
case 0x52: /* EOR (indz) 65C02 */
break;
case 0x53:
break;
case 0x54:
break;
case 0x55: /* EOR zero page, X */
A ^= rZEROX;
SIGN(A);
ZERO(A);
break;
case 0x56: /* LSR zero page, X */
ZEROX;
tmp = REFzero;
C = (tmp & 0x01);
tmp = tmp >> 1;
SETzero(tmp);
N = 0;
ZERO(tmp);
break;
case 0x57:
break;
case 0x58: /* CLI */
I = 0;
break;
case 0x59: /* EOR absolute, Y */
ABSY;
A ^= REFptr;
SIGN(A);
ZERO(A);
break;
case 0x5A: /* PHY 65C02 */
break;
case 0x5B:
break;
case 0x5C:
break;
case 0x5D: /* EOR absolute, X */
ABSX;
A ^= REFptr;
SIGN(A);
ZERO(A);
break;
case 0x5E: /* LSR absolute, X */
ABSX;
tmp = REFptr;
C = (tmp & 0x01);
tmp = tmp >> 1;
SETptr(tmp);
N = 0;
ZERO(tmp);
break;
case 0x5F:
break;
case 0x60: /* RTS */
DO_RTS;
break;
case 0x61: /* ADC (indirect, X) */
INDX;
val = REFptr;
tmp = A & 0x80;
stmp = val & 0x80;
if (D) {
num = tobinary(val);
val = tobinary(A);
val += num + C;
dCARRY(val);
while (val >= 100)
val -= 100;
A = tobcd(val);
} else {
A += val + C;
CARRY(A);
A &= 0xFF;
}
ZERO(A);
SIGN(A);
V = (tmp == stmp) && (tmp != N);
break;
case 0x62:
break;
case 0x63:
break;
case 0x64: /* STZ zero page 65C02 */
break;
case 0x65: /* ADC zero page */
val = rZEROP;
tmp = A & 0x80;
stmp = val & 0x80;
if (D) {
num = tobinary(val);
val = tobinary(A);
val += num + C;
dCARRY(val);
while (val >= 100)
val -= 100;
A = tobcd(val);
} else {
A += val + C;
CARRY(A);
A &= 0xFF;
}
ZERO(A);
SIGN(A);
V = (tmp == stmp) && (tmp != N);
break;
case 0x66: /* ROR zero page */
ZEROP;
val = REFzero;
tmp = C;
C = val & 0x01;
val = val >> 1;
val |= tmp << 7;
SETzero(val);
SIGN(val);
ZERO(val);
break;
case 0x67:
break;
case 0x68: /* PLA */
A = pop();
SIGN(A);
ZERO(A);
break;
case 0x69: /* ADC immediate */
val = REFimm;
tmp = A & 0x80;
stmp = val & 0x80;
if (D) {
num = tobinary(val);
val = tobinary(A);
val += num + C;
dCARRY(val);
while (val >= 100)
val -= 100;
A = tobcd(val);
} else {
A += val + C;
CARRY(A);
A &= 0xFF;
}
ZERO(A);
SIGN(A);
V = (tmp == stmp) && (tmp != N);
break;
case 0x6A: /* ROR accumulator */
tmp = C;
C = A & 0x01;
A = A >> 1;
A |= tmp << 7;
SIGN(A);
ZERO(A);
break;
case 0x6B:
break;
case 0x6C: /* JMP indirect */
ptmp = REFimm;
ptmp |= REFimm << 8;
Pc = mem[ptmp++];
Pc |= mem[ptmp] << 8;
if (jmp_tbl[Pc])
jump(jmp_tbl[Pc]);
break;
case 0x6D: /* ADC absolute */
ABSOL;
val = REFptr;
tmp = A & 0x80;
stmp = val & 0x80;
if (D) {
num = tobinary(val);
val = tobinary(A);
val += num + C;
dCARRY(val);
while (val >= 100)
val -= 100;
A = tobcd(val);
} else {
A += val + C;
CARRY(A);
A &= 0xFF;
}
ZERO(A);
SIGN(A);
V = (tmp == stmp) && (tmp != N);
break;
case 0x6E: /* ROR absolute */
ABSOL;
val = REFptr;
tmp = C;
C = val & 0x01;
val = val >> 1;
val |= tmp << 7;
SETptr(val);
SIGN(val);
ZERO(val);
break;
case 0x6F:
break;
case 0x70: /* BVS */
if (V) {
BRANCH();
} else {
PCINC;
}
break;
case 0x71: /* ADC (indirect),Y */
INDY;
val = REFptr;
tmp = A & 0x80;
stmp = val & 0x80;
if (D) {
num = tobinary(val);
val = tobinary(A);
val += num + C;
dCARRY(val);
while (val >= 100)
val -= 100;
A = tobcd(val);
} else {
A += val + C;
CARRY(A);
A &= 0xFF;
}
ZERO(A);
SIGN(A);
V = (tmp == stmp) && (tmp != N);
break;
case 0x72: /* ADC (indz) 65C02 */
break;
case 0x73:
break;
case 0x74: /* STZ zero page, X 65C02 */
break;
case 0x75: /* ADC zero page, X */
val = rZEROX;
tmp = A & 0x80;
stmp = val & 0x80;
if (D) {
num = tobinary(val);
val = tobinary(A);
val += num + C;
dCARRY(val);
while (val >= 100)
val -= 100;
A = tobcd(val);
} else {
A += val + C;
CARRY(A);
A &= 0xFF;
}
ZERO(A);
SIGN(A);
V = (tmp == stmp) && (tmp != N);
break;
case 0x76: /* ROR zero page, X */
ZEROX;
val = REFzero;
tmp = C;
C = val & 0x01;
val = val >> 1;
val |= tmp << 7;
SETzero(val);
SIGN(val);
ZERO(val);
break;
case 0x77:
break;
case 0x78: /* SEI */
I = 1;
break;
case 0x79: /* ADC absolute, Y */
ABSY;
val = REFptr;
tmp = A & 0x80;
stmp = val & 0x80;
if (D) {
num = tobinary(val);
val = tobinary(A);
val += num + C;
dCARRY(val);
while (val >= 100)
val -= 100;
A = tobcd(val);
} else {
A += val + C;
CARRY(A);
A &= 0xFF;
}
ZERO(A);
SIGN(A);
V = (tmp == stmp) && (tmp != N);
break;
case 0x7A: /* PLY 65C02 */
break;
case 0x7B:
break;
case 0x7C: /* JMP (abs indirect, X) 65C02 */
break;
case 0x7D: /* ADC absolute, X */
ABSX;
val = REFptr;
tmp = A & 0x80;
stmp = val & 0x80;
if (D) {
num = tobinary(val);
val = tobinary(A);
val += num + C;
dCARRY(val);
while (val >= 100)
val -= 100;
A = tobcd(val);
} else {
A += val + C;
CARRY(A);
A &= 0xFF;
}
ZERO(A);
SIGN(A);
V = (tmp == stmp) && (tmp != N);
break;
case 0x7E: /* ROR absolute, X */
ABSX;
val = REFptr;
tmp = C;
C = val & 0x01;
val = val >> 1;
val |= tmp << 7;
SETptr(val);
SIGN(val);
ZERO(val);
break;
case 0x7F:
break;
case 0x80: /* BRA 65C02 */
break;
case 0x81: /* STA (indirect, X) */
INDX;
SETptr(A);
break;
case 0x82:
break;
case 0x83:
break;
case 0x84: /* STY zero page */
sZEROP(Y);
break;
case 0x85: /* STA zero page */
sZEROP(A);
break;
case 0x86: /* STX zero page */
sZEROP(X);
break;
case 0x87:
break;
case 0x88: /* DEY */
Y--;
SIGN(Y);
ZERO(Y);
break;
case 0x89:
break;
case 0x8A: /* TXA */
A = X;
SIGN(A);
ZERO(A);
break;
case 0x8B:
break;
case 0x8C: /* STY absolute */
ABSOL;
SETptr(Y);
break;
case 0x8D: /* STA absolute */
ABSOL;
SETptr(A);
break;
case 0x8E: /* STX absolute */
ABSOL;
SETptr(X);
break;
case 0x8F:
break;
case 0x90: /* BCC */
if (C) {
PCINC;
} else {
BRANCH();
}
break;
case 0x91: /* STA (indirect), Y */
INDY;
SETptr(A);
break;
case 0x92:
break;
case 0x93:
break;
case 0x94: /* STY zero page, X */
sZEROX(Y);
break;
case 0x95: /* STA zero page, X */
sZEROX(A);
break;
case 0x96: /* STX zero page, Y */
sZEROY(X);
break;
case 0x97:
break;
case 0x98: /* TYA */
A = Y;
SIGN(A);
ZERO(A);
break;
case 0x99: /* STA absolute, Y */
ABSY;
SETptr(A);
break;
case 0x9A: /* TXS */
Sp = X;
break;
case 0x9B:
break;
case 0x9C: /* STZ absolute 65C02 */
break;
case 0x9D: /* STA absolute, X */
ABSX;
SETptr(A);
break;
case 0x9E: /* STZ absolute, X 65C02 */
break;
case 0x9F:
break;
case 0xA0: /* LDY immediate */
Y = REFimm;
SIGN(Y);
ZERO(Y);
break;
case 0xA1: /* LDA (indirect, X) */
INDX;
A = REFptr;
SIGN(A);
ZERO(A);
break;
case 0xA2: /* LDX immediate */
X = REFimm;
SIGN(X);
ZERO(X);
break;
case 0xA3:
break;
case 0xA4: /* LDY zero page */
Y = rZEROP;
SIGN(Y);
ZERO(Y);
break;
case 0xA5: /* LDA zero page */
A = rZEROP;
SIGN(A);
ZERO(A);
break;
case 0xA6: /* LDX zero page */
X = rZEROP;
SIGN(X);
ZERO(X);
break;
case 0xA7:
break;
case 0xA8: /* TAY */
Y = A;
SIGN(Y);
ZERO(Y);
break;
case 0xA9: /* LDA immediate */
A = REFimm;
SIGN(A);
ZERO(A);
break;
case 0xAA: /* TAX */
X = A;
SIGN(X);
ZERO(X);
break;
case 0xAB:
break;
case 0xAC: /* LDY absolute */
ABSOL;
Y = REFptr;
SIGN(Y);
ZERO(Y);
break;
case 0xAD: /* LDA absolute */
ABSOL;
A = REFptr;
SIGN(A);
ZERO(A);
break;
case 0xAE: /* LDX absolute */
ABSOL;
X = REFptr;
SIGN(X);
ZERO(X);
break;
case 0xAF:
break;
case 0xB0: /* BCS */
if (C) {
BRANCH();
} else {
PCINC;
}
break;
case 0xB1: /* LDA (indirect), Y */
INDY;
A = REFptr;
SIGN(A);
ZERO(A);
break;
case 0xB2: /* LDA (indz) 65C02 */
break;
case 0xB3:
break;
case 0xB4: /* LDY zero page, X */
Y = rZEROX;
SIGN(Y);
ZERO(Y);
break;
case 0xB5: /* LDA zero page, X */
A = rZEROX;
SIGN(A);
ZERO(A);
break;
case 0xB6: /* LDX zero page, Y */
X = rZEROY;
SIGN(X);
ZERO(X);
break;
case 0xB7:
break;
case 0xB8: /* CLV */
V = 0;
break;
case 0xB9: /* LDA absolute, Y */
ABSY;
A = REFptr;
SIGN(A);
ZERO(A);
break;
case 0xBA: /* TSX */
X = Sp;
SIGN(X);
ZERO(X);
break;
case 0xBB:
break;
case 0xBC: /* LDY absolute, X */
ABSX;
Y = REFptr;
SIGN(Y);
ZERO(Y);
break;
case 0xBD: /* LDA absolute, X */
ABSX;
A = REFptr;
SIGN(A);
ZERO(A);
break;
case 0xBE: /* LDX absolute, Y */
ABSY;
X = REFptr;
SIGN(X);
ZERO(X);
break;
case 0xBF:
break;
case 0xC0: /* CPY immediate */
tmp = REFimm;
C = (Y >= tmp);
tmp = (Y - tmp) & 0xFF;
SIGN(tmp);
ZERO(tmp);
break;
case 0xC1: /* CMP (indirect, X) */
INDX;
tmp = REFptr;
C = (A >= tmp);
tmp = (A - tmp) & 0xFF;
SIGN(tmp);
ZERO(tmp);
break;
case 0xC2:
break;
case 0xC3:
break;
case 0xC4: /* CPY zero page */
tmp = rZEROP;
C = (Y >= tmp);
tmp = (Y - tmp) & 0xFF;
SIGN(tmp);
ZERO(tmp);
break;
case 0xC5: /* CMP zero page */
tmp = rZEROP;
C = (A >= tmp);
tmp = (A - tmp) & 0xFF;
SIGN(tmp);
ZERO(tmp);
break;
case 0xC6: /* DEC zero page */
ZEROP;
stmp = REFzero - 1;
SETzero(stmp);
SIGN(stmp);
ZERO(stmp);
break;
case 0xC7:
break;
case 0xC8: /* INY */
Y++;
SIGN(Y);
ZERO(Y);
break;
case 0xC9: /* CMP immediate */
tmp = REFimm;
C = (A >= tmp);
tmp = (A - tmp) & 0xFF;
SIGN(tmp);
ZERO(tmp);
break;
case 0xCA: /* DEX */
X--;
SIGN(X);
ZERO(X);
break;
case 0xCB:
break;
case 0xCC: /* CPY absolute */
ABSOL;
tmp = REFptr;
C = (Y >= tmp);
tmp = (Y - tmp) & 0xFF;
SIGN(tmp);
ZERO(tmp);
break;
case 0xCD: /* CMP absolute */
ABSOL;
tmp = REFptr;
C = (A >= tmp);
tmp = (A - tmp) & 0xFF;
SIGN(tmp);
ZERO(tmp);
break;
case 0xCE: /* DEC absolute */
ABSOL;
stmp = REFptr - 1;
SETptr(stmp);
SIGN(stmp);
ZERO(stmp);
break;
case 0xCF:
break;
case 0xD0: /* BNE */
if (NZ) {
BRANCH();
} else {
PCINC;
}
break;
case 0xD1: /* CMP (indirect), Y */
INDY;
tmp = REFptr;
C = (A >= tmp);
tmp = (A - tmp) & 0xFF;
SIGN(tmp);
ZERO(tmp);
break;
case 0xD2: /* CMP (indz) 65C02 */
break;
case 0xD3:
break;
case 0xD4:
break;
case 0xD5: /* CMP zero page, X */
tmp = rZEROX;
C = (A >= tmp);
tmp = (A - tmp) & 0xFF;
SIGN(tmp);
ZERO(tmp);
break;
case 0xD6: /* DEC zero page, X */
ZEROX;
stmp = REFzero - 1;
SETzero(stmp);
SIGN(stmp);
ZERO(stmp);
break;
case 0xD7:
break;
case 0xD8: /* CLD */
D = 0;
break;
case 0xD9: /* CMP absolute, Y */
ABSY;
tmp = REFptr;
C = (A >= tmp);
tmp = (A - tmp) & 0xFF;
SIGN(tmp);
ZERO(tmp);
break;
case 0xDA: /* PHX 65C02 */
break;
case 0xDB:
break;
case 0xDC:
break;
case 0xDD: /* CMP absolute, X */
ABSX;
tmp = REFptr;
C = (A >= tmp);
tmp = (A - tmp) & 0xFF;
SIGN(tmp);
ZERO(tmp);
break;
case 0xDE: /* DEC absolute, X */
ABSX;
stmp = REFptr - 1;
SETptr(stmp);
SIGN(stmp);
ZERO(stmp);
break;
case 0xDF:
break;
case 0xE0: /* CPX immediate */
tmp = REFimm;
C = (X >= tmp);
tmp = (X - tmp) & 0xFF;
SIGN(tmp);
ZERO(tmp);
break;
case 0xE1: /* SBC (indirect, X) */
INDX;
val = REFptr;
tmp = A & 0x80;
stmp = val & 0x80;
if (D) {
assert(FALSE);
} else {
foo = A - (val + !C);
C = (foo >= 0);
A = foo & 0xFF;
}
ZERO(A);
SIGN(A);
V = (tmp != stmp) && (tmp != N);
break;
case 0xE2:
break;
case 0xE3:
break;
case 0xE4: /* CPX zero page */
tmp = rZEROP;
C = (X >= tmp);
tmp = (X - tmp) & 0xFF;
SIGN(tmp);
ZERO(tmp);
break;
case 0xE5: /* SBC zero page */
val = rZEROP;
tmp = A & 0x80;
stmp = val & 0x80;
if (D) {
assert(FALSE);
} else {
foo = A - (val + !C);
C = (foo >= 0);
A = foo & 0xFF;
}
ZERO(A);
SIGN(A);
V = (tmp != stmp) && (tmp != N);
break;
case 0xE6: /* INC zero page */
ZEROP;
stmp = REFzero + 1;
SIGN(stmp);
ZERO(stmp);
SETzero(stmp);
break;
case 0xE7:
break;
case 0xE8: /* INX */
X++;
SIGN(X);
ZERO(X);
break;
case 0xE9: /* SBC immediate */
val = REFimm;
tmp = A & 0x80;
stmp = val & 0x80;
if (D) {
assert(FALSE);
} else {
foo = A - (val + !C);
C = (foo >= 0);
A = foo & 0xFF;
}
ZERO(A);
SIGN(A);
V = (tmp != stmp) && (tmp != N);
break;
case 0xEA: /* NOP */
break;
case 0xEB:
break;
case 0xEC: /* CPX absolute */
ABSOL;
tmp = REFptr;
C = (X >= tmp);
tmp = (X - tmp) & 0xFF;
SIGN(tmp);
ZERO(tmp);
break;
case 0xED: /* SBC absolute */
ABSOL;
val = REFptr;
tmp = A & 0x80;
stmp = val & 0x80;
if (D) {
assert(FALSE);
} else {
foo = A - (val + !C);
C = (foo >= 0);
A = foo & 0xFF;
}
ZERO(A);
SIGN(A);
V = (tmp != stmp) && (tmp != N);
break;
case 0xEE: /* INC absolute */
ABSOL;
stmp = REFptr + 1;
SETptr(stmp);
SIGN(stmp);
ZERO(stmp);
break;
case 0xEF:
break;
case 0xF0: /* BEQ */
if (NZ) {
PCINC;
} else {
BRANCH();
}
break;
case 0xF1: /* SBC (indirect), Y */
INDY;
val = REFptr;
tmp = A & 0x80;
stmp = val & 0x80;
if (D) {
assert(FALSE);
} else {
foo = A - (val + !C);
C = (foo >= 0);
A = foo & 0xFF;
}
ZERO(A);
SIGN(A);
V = (tmp != stmp) && (tmp != N);
break;
case 0xF2: /* SBC (indz) 65C02 */
break;
case 0xF3:
break;
case 0xF4:
break;
case 0xF5: /* SBC zero page, X */
val = rZEROX;
tmp = A & 0x80;
stmp = val & 0x80;
if (D) {
assert(FALSE);
} else {
foo = A - (val + !C);
C = (foo >= 0);
A = foo & 0xFF;
}
ZERO(A);
SIGN(A);
V = (tmp != stmp) && (tmp != N);
break;
case 0xF6: /* INC zero page, X */
ZEROX;
stmp = REFzero + 1;
SETzero(stmp);
SIGN(stmp);
ZERO(stmp);
break;
case 0xF7:
break;
case 0xF8: /* SED */
D = 1;
break;
case 0xF9: /* SBC absolute, Y */
ABSY;
val = REFptr;
tmp = A & 0x80;
stmp = val & 0x80;
if (D) {
assert(FALSE);
} else {
foo = A - (val + !C);
C = (foo >= 0);
A = foo & 0xFF;
}
ZERO(A);
SIGN(A);
V = (tmp != stmp) && (tmp != N);
break;
case 0xFA: /* PLX 65C02 */
break;
case 0xFB:
break;
case 0xFC:
break;
case 0xFD: /* SBC absolute, X */
ABSX;
val = REFptr;
tmp = A & 0x80;
stmp = val & 0x80;
if (D) {
assert(FALSE);
} else {
foo = A - (val + !C);
C = (foo >= 0);
A = foo & 0xFF;
}
ZERO(A);
SIGN(A);
V = (tmp != stmp) && (tmp != N);
break;
case 0xFE: /* INC absolute, X */
ABSX;
stmp = REFptr + 1;
SETptr(stmp);
SIGN(stmp);
ZERO(stmp);
break;
case 0xFF:
break;
}
} while (running);
if (show_flags)
flags(logging_fp);
} while (tracing);
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.