def main():
cpu = Cpu()
cpu.load_rom('games/UFO')
while cpu.running:
# each instruction is 2bytes long
# so they need to be put together
high_byte = cpu.memory[cpu.program_counter]
low_byte = cpu.memory[cpu.program_counter+1]
opcode = high_byte << 8 | low_byte
cpu.opcode = OpCode(opcode)
instruction = cpu.instruction_mapping.get(cpu.opcode.identifier, None)
if not instruction:
raise Exception('Instruction not found {:x}'.format(cpu.opcode))
else:
instruction()
cpu.program_counter += 2
