diff options
Diffstat (limited to 'cpu.c')
| -rw-r--r-- | cpu.c | 19 |
1 files changed, 10 insertions, 9 deletions
@@ -127,9 +127,7 @@ opcode_mem(enum addressing_mode mode) val = (arg + regs.y) % 256; break; case AM_REL: - val = arg + regs.pc; - if (((regs.pc + 1) & 0xFF00) != (val & 0xFF00)) - val -= 0x0100; + val = (int8_t)arg + regs.pc; break; case AM_IMM: case AM_ABS: @@ -174,6 +172,9 @@ branch(uint16_t addr, bool cond) return; cycles++; + if (((regs.pc + 1) & 0xFF00) != (addr & 0xFF00)) + cycles++; + regs.pc = addr; } @@ -277,7 +278,7 @@ BRK(uint16_t arg) { /* TODO: push regs.pc and regs.status to stack and load IRQ vector */ regs.status.brk = 1; - // exit(0); + exit(0); } void @@ -771,11 +772,11 @@ DCP(uint16_t arg) memwrite(arg, tmp); regs.status.carry = tmp <= regs.a; - STATUS_UPDATE_NZ(tmp); + STATUS_UPDATE_NZ(regs.a - tmp); } void -ISC(uint16_t arg) +ISB(uint16_t arg) { INC(arg); SBC(peek(arg)); @@ -807,7 +808,7 @@ void RLA(uint16_t arg) { ROL(arg); - AND(arg); + AND(peek(arg)); } void @@ -821,14 +822,14 @@ void SLO(uint16_t arg) { ASL(arg); - ORA(arg); + ORA(peek(arg)); } void SRE(uint16_t arg) { LSR(arg); - EOR(arg); + EOR(peek(arg)); } void |