chip8.py

import pygame
import sys
import random

# Chip-8 Emulator Constants
MEMORY_SIZE = 4096
REGISTER_COUNT = 16
STACK_SIZE = 16
PROGRAM_START_ADDRESS = 0x200
FONTSET_START_ADDRESS = 0x50
DISPLAY_WIDTH = 64
DISPLAY_HEIGHT = 32
DISPLAY_SCALE = 10
REFRESH_RATE = 60

# Chip-8 Emulator Variables
memory = [0] * MEMORY_SIZE
registers = [0] * REGISTER_COUNT
I = 0
pc = PROGRAM_START_ADDRESS
opcode = 0
stack = [0] * STACK_SIZE
sp = 0
display = [[0] * DISPLAY_WIDTH for _ in range(DISPLAY_HEIGHT)]
keys = [0] * 16
delay_timer = 0
sound_timer = 0

# Chip-8 Fontset
fontset = [
    0xF0, 0x90, 0x90, 0x90, 0xF0,  # 0
    0x20, 0x60, 0x20, 0x20, 0x70,  # 1
    0xF0, 0x10, 0xF0, 0x80, 0xF0,  # 2
    0xF0, 0x10, 0xF0, 0x10, 0xF0,  # 3
    0x90, 0x90, 0xF0, 0x10, 0x10,  # 4
    0xF0, 0x80, 0xF0, 0x10, 0xF0,  # 5
    0xF0, 0x80, 0xF0, 0x90, 0xF0,  # 6
    0xF0, 0x10, 0x20, 0x40, 0x40,  # 7
    0xF0, 0x90, 0xF0, 0x90, 0xF0,  # 8
    0xF0, 0x90, 0xF0, 0x10, 0xF0,  # 9
    0xF0, 0x90, 0xF0, 0x90, 0x90,  # A
    0xE0, 0x90, 0xE0, 0x90, 0xE0,  # B
    0xF0, 0x80, 0x80, 0x80, 0xF0,  # C
    0xE0, 0x90, 0x90, 0x90, 0xE0,  # D
    0xF0, 0x80, 0xF0, 0x80, 0xF0,  # E
    0xF0, 0x80, 0xF0, 0x80, 0x80   # F
]

def load_rom(rom_path):
    rom_file = open(rom_path, "rb")
    rom_data = rom_file.read()
    rom_file.close()

    for i, byte in enumerate(rom_data):
        memory[PROGRAM_START_ADDRESS + i] = byte

def emulate_cycle():
    global pc, opcode, sp, delay_timer, sound_timer

    # Fetch opcode
    opcode = memory[pc] << 8 | memory[pc + 1]

    # Decode and execute opcode
    # ...

    # Update timers
    if delay_timer > 0:
        delay_timer -= 1

    if sound_timer > 0:
        if sound_timer == 1:
            print("BEEP!")  # Placeholder for sound playback
        sound_timer -= 1

def main():
    global pc, display, keys

    if len(sys.argv) != 2:
        print("Usage: chip8.py <rom_path>")
        return

    rom_path = sys.argv[1]

    # Initialize Chip-8 emulator
    pc = PROGRAM_START_ADDRESS
    load_rom(rom_path)
    memory[FONTSET_START_ADDRESS:FONTSET_START_ADDRESS + len(fontset)] = fontset

    # Initialize pygame
    pygame.init()
    clock = pygame.time.Clock()
    screen = pygame.display.set_mode((DISPLAY_WIDTH * DISPLAY_SCALE, DISPLAY_HEIGHT * DISPLAY_SCALE))
    pygame.display.set_caption("Chip-8 Emulator")

    # Emulation loop
    while True:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                sys.exit()

            # Handle key press events
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_1:
                    keys[0x1] = 1
                elif event.key == pygame.K_2:
                    keys[0x2] = 1
                elif event.key == pygame.K_3:
                    keys[0x3] = 1
                elif event.key == pygame.K_4:
                    keys[0xC] = 1
                elif event.key == pygame.K_q:
                    keys[0x4] = 1
                elif event.key == pygame.K_w:
                    keys[0x5] = 1
                elif event.key == pygame.K_e:
                    keys[0x6] = 1
                elif event.key == pygame.K_r:
                    keys[0xD] = 1
                elif event.key == pygame.K_a:
                    keys[0x7] = 1
                elif event.key == pygame.K_s:
                    keys[0x8] = 1
                elif event.key == pygame.K_d:
                    keys[0x9] = 1
                elif event.key == pygame.K_f:
                    keys[0xE] = 1
                elif event.key == pygame.K_z:
                    keys[0xA] = 1
                elif event.key == pygame.K_x:
                    keys[0x0] = 1
                elif event.key == pygame.K_c:
                    keys[0xB] = 1
                elif event.key == pygame.K_v:
                    keys[0xF] = 1

            # Handle key release events
            if event.type == pygame.KEYUP:
                if event.key == pygame.K_1:
                    keys[0x1] = 0
                elif event.key == pygame.K_2:
                    keys[0x2] = 0
                elif event.key == pygame.K_3:
                    keys[0x3] = 0
                elif event.key == pygame.K_4:
                    keys[0xC] = 0
                elif event.key == pygame.K_q:
                    keys[0x4] = 0
                elif event.key == pygame.K_w:
                    keys[0x5] = 0
                elif event.key == pygame.K_e:
                    keys[0x6] = 0
                elif event.key == pygame.K_r:
                                        keys[0xD] = 0
                elif event.key == pygame.K_a:
                    keys[0x7] = 0
                elif event.key == pygame.K_s:
                    keys[0x8] = 0
                elif event.key == pygame.K_d:
                    keys[0x9] = 0
                elif event.key == pygame.K_f:
                    keys[0xE] = 0
                elif event.key == pygame.K_z:
                    keys[0xA] = 0
                elif event.key == pygame.K_x:
                    keys[0x0] = 0
                elif event.key == pygame.K_c:
                    keys[0xB] = 0
                elif event.key == pygame.K_v:
                    keys[0xF] = 0

        # Emulate a cycle
        emulate_cycle()

        # Update the display
        for y in range(DISPLAY_HEIGHT):
            for x in range(DISPLAY_WIDTH):
                pixel = display[y][x]
                rect = pygame.Rect(x * DISPLAY_SCALE, y * DISPLAY_SCALE, DISPLAY_SCALE, DISPLAY_SCALE)

                if pixel == 1:
                    pygame.draw.rect(screen, (255, 255, 255), rect)
                else:
                    pygame.draw.rect(screen, (0, 0, 0), rect)

        pygame.display.flip()
        clock.tick(REFRESH_RATE)

if __name__ == "__main__":
    main()


# ...

def emulate_cycle():
    global pc, opcode, sp, delay_timer, sound_timer

    opcode = (memory[pc] << 8) | memory[pc + 1]

    # Decode and execute opcode
    if opcode == 0x00E0:
        # Clear the display
        for y in range(DISPLAY_HEIGHT):
            for x in range(DISPLAY_WIDTH):
                display[y][x] = 0
        pc += 2
    elif opcode == 0x00EE:
        # Return from subroutine
        pc = stack[sp]
        sp -= 1
        pc += 2
    elif opcode & 0xF000 == 0x1000:
        # Jump to address NNN
        address = opcode & 0x0FFF
        pc = address
    elif opcode & 0xF000 == 0x2000:
        # Call subroutine at address NNN
        address = opcode & 0x0FFF
        sp += 1
        stack[sp] = pc
        pc = address
    elif opcode & 0xF000 == 0x3000:
        # Skip next instruction if VX == NN
        vx = (opcode & 0x0F00) >> 8
        nn = opcode & 0x00FF
        if registers[vx] == nn:
            pc += 4
        else:
            pc += 2
    # Implement other opcodes...

    # Update timers
    if delay_timer > 0:
        delay_timer -= 1
    if sound_timer > 0:
        if sound_timer == 1:
            print("BEEP!")  # Placeholder for sound playback
        sound_timer -= 1

def main():
    # ...

    # Emulation loop
    while True:
        # ...

        # Emulate a cycle
        emulate_cycle()

        # Update the display
        # ...

        pygame.display.flip()
        clock.tick(REFRESH_RATE)


    # Update the display
    for y in range(DISPLAY_HEIGHT):
        for x in range(DISPLAY_WIDTH):
            pixel = display[y][x]
            rect = pygame.Rect(x * DISPLAY_SCALE, y * DISPLAY_SCALE, DISPLAY_SCALE, DISPLAY_SCALE)

            if pixel == 1:
                pygame.draw.rect(screen, (255, 255, 255), rect)
            else:
                pygame.draw.rect(screen, (0, 0, 0), rect)