diff options
Diffstat (limited to 'emulator.c')
| -rw-r--r-- | emulator.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/emulator.c b/emulator.c index 57fc3f3..fe7693f 100644 --- a/emulator.c +++ b/emulator.c @@ -46,6 +46,8 @@ int emulator_load_rom(Emulator* emulator, char* rom_name) //rom loaded after 0x200 into memory int bytes_read = fread(emulator->memory + GAME_LOAD_LOCATION, 1, st.st_size, rom); + fclose(rom); + if(bytes_read != st.st_size) { perror("doesnt cuadrar\n"); @@ -59,5 +61,39 @@ int emulator_load_rom(Emulator* emulator, char* rom_name) int emulator_tick(Emulator* emulator) { + uint16_t* pc = &emulator->pc; + uint16_t instr = (emulator->memory[*pc] << 8) | emulator->memory[*pc + 1]; + *pc += 2; + + uint8_t first_nibble = (instr >> 12) & 0xf; + uint8_t X = (instr & 0x0F00) >> 8; //second_nibble + uint8_t Y = (instr & 0x00F0) >> 4; //third_nibble + uint8_t N = (instr & 0x000F); //fourth_nibble + uint8_t NN = (instr & 0x00FF); //second_byte + uint16_t NNN = (instr & 0x0FFF); //last three nibbles + + printf("instr: 0x%x\n", instr); + printf("A: 0x%x\nX: 0x%x\nY: 0x%x\nN: 0x%x\nNN: 0x%x\nNNN: 0x%x\n\n", first_nibble, X, Y, N, NN, NNN); + + switch(first_nibble) + { + case 1: + break; + case 2: + break; + case 3: + break; + case 4: + break; + case 5: + break; + case 6: + break; + case 7: + break; + case 8: + break; + } + return 0; } |