copy-sprites.py

#!/usr/bin/env python
# This script copies character sprite data from the source ROM into the destination ROM.

#All sprites are 0x200 in size (ie 0x25000-0x251FF)

#Fighter = 0x25000        Knight = 0x25C00
#Thief = 0x25200          Ninja = 0x25E00
#BlackBelt = 0x25400      Master = 0x26000
#RedMage = 0x25600        RedWizard = 0x26200
#WhiteMage = 0x25800      WhiteWizard = 0x26400
#BlackMage = 0x25A00      BlackWizard = 0x26600

import sys

if len(sys.argv) < 2:
    print("Usage: copy_sprites.py <source> <destination>")
    sys.exit(1)
else:
    source_rom = sys.argv[1]
    dest_rom   = sys.argv[2]

sprites = {
    'fighter'   : { 'offset': 0x25000, 'data': b'' },
    'knight'    : { 'offset': 0x25C00, 'data': b'' },
    'thief'     : { 'offset': 0x25200, 'data': b'' },
    'ninja'     : { 'offset': 0x25E00, 'data': b'' },
    'blackbelt' : { 'offset': 0x25400, 'data': b'' },
    'master'    : { 'offset': 0x26000, 'data': b'' },
    'redmage'   : { 'offset': 0x25600, 'data': b'' },
    'redwizard' : { 'offset': 0x26200, 'data': b'' },
    'whitemage' : { 'offset': 0x25800, 'data': b'' },
    'whitewiz'  : { 'offset': 0x26400, 'data': b'' },
    'blackmage' : { 'offset': 0x25A00, 'data': b'' },
    'blackwiz'  : { 'offset': 0x26600, 'data': b'' },
}

# Read sprite data into memory
with open(source_rom, 'r+b') as f:
    for k in sprites:
        f.seek(sprites[k]['offset'])
        sprites[k]['data'] = f.read(0x200)
    f.seek(0)
    f.seek(0x9000)
    map_sprites = f.read(0xC00)

with open(dest_rom, 'r+b') as f:
    data = bytearray(f.read())
    # Update map sprites
    data[0x9000:0x9C00] = map_sprites

    # Update sprite data in memory
    for k in sprites:
        offset = sprites[k]['offset']
        data[offset:offset+0x200] = sprites[k]['data']
    # Write ROM data to file
    f.seek(0)
    f.write(data)