diff options
| -rw-r--r-- | config.h | 3 | ||||
| -rw-r--r-- | emulator.c | 12 |
2 files changed, 9 insertions, 6 deletions
diff --git a/config.h b/config.h index 38d0ce7..19677a0 100644 --- a/config.h +++ b/config.h @@ -2,6 +2,7 @@ #define _CONFIG_H_ #define DEBUG 1 +#define COSMAC_VIP_COMPATIBILITY 1 //if set to != 0 it will change the emulator to work with Cosmac VIP era's games //#define STOP_ON_INFINITE_LOOP #define SCREEN_WIDTH 852 @@ -17,5 +18,7 @@ #define dbgprintf(fmt, ...) \ do { if(DEBUG) fprintf (stdout, fmt, ##__VA_ARGS__); } while(0) +#define COSMAC_VIP(code) \ + do { if(COSMAC_VIP_COMPATIBILITY) code else ; } while(0); #endif diff --git a/emulator.c b/emulator.c index 8fed056..466a9f2 100644 --- a/emulator.c +++ b/emulator.c @@ -248,8 +248,8 @@ int emulator_tick(Emulator* emulator) emulator->regs.V[X] -= emulator->regs.V[Y]; break; case 0x6: - emulator->regs.V[X] = emulator->regs.V[X] >> 1; - emulator->regs.VF = N == 0x1 ? 1 : 0; + emulator->regs.VF = emulator->regs.V[X] & 0x1; + emulator->regs.V[X] >>= 1; break; case 0x7: if(emulator->regs.V[Y] > emulator->regs.V[X]) @@ -259,8 +259,8 @@ int emulator_tick(Emulator* emulator) emulator->regs.V[X] = emulator->regs.V[Y] - emulator->regs.V[X]; break; case 0xE: - emulator->regs.V[X] = emulator->regs.V[X] << 1; - emulator->regs.VF = first_nibble == 0x1 ? 1 : 0; + emulator->regs.VF = emulator->regs.V[X] >> 7; + emulator->regs.V[X] <<= 1; break; default: printf("DEFAULT: Instr: 0x%x\n", instr); @@ -342,12 +342,12 @@ int emulator_tick(Emulator* emulator) case 0x55: //FX55 for (int i = 0; i <= X; ++i) emulator->memory[emulator->regs.I + i] = emulator->regs.V[i]; - emulator->regs.I += X + 1; + COSMAC_VIP(emulator->regs.I += X + 1;) break; case 0x65: //FX65 for (int i = 0; i <= X; ++i) emulator->regs.V[i] = emulator->memory[emulator->regs.I + i]; - emulator->regs.I += X + 1; + COSMAC_VIP(emulator->regs.I += X + 1;) break; case 0x15: //FX15 dbgprintf("SET THE DELAY TIMER TO V[X]!\n"); |