Resident Evil 3 : Nemesis (Biohazard 3 – Last Escape): Resident Evil 3 - PS1 Modders Edition

Resident Evil 3 - PS1 Modders Edition v1.0

1:This mod disables a checksum on the PS1 version of RE3 that would previously prohibit people from modifying the disc with custom textures. Normally this would have caused a crash. There might be more benefits from this disabled checksum that have yet to be discovered. Make sure to not exceed normal file limits (This is something to address in the near future for a V1.1)

2:The EXE (SLUS_009.23) has been expanded by adjusting the header and padding most of it with 00's besides some info text. From 000D4000 till 000F07FF free space is added, giving about 116735 bytes of extra space for people to do custom code. On the PSX ram the location would be from 800E3800 till 800FFFFF ending right before the stack.

3:To easily find assembly code locations that are within the range of the EXE you can take the PSX ram address of your assembly code and sub 8000F800 from it to find it on the EXE. This will generally only work for non dynamic memory, however you can still manually find arrays of dynamic memory and modify them to make a call to the new empty space and do all kinds of cool stuff.

4:To apply the patch run the RE3 Modders Edition v1.0.exe in the same folder where "Resident Evil 3 - Nemesis (USA).bin" is located.

RE3 PS1 Modders Edition v1.0

1:This mod disables a checksum on the PS1 version of RE3 that would previously prohibit people from modifying the disc with custom textures. Normally this would have caused a crash. There might be more benefits from this disabled checksum that have yet to be discovered. Make sure to not exceed normal file limits (This is something to address in the near future for a V1.1)

2:The EXE (SLUS_009.23) has been expanded by adjusting the header and padding most of it with 00's besides some info text. From 000D4000 till 000F07FF free space is added, giving about 116735 bytes of extra space for people to do custom code. On the PSX ram the location would be from 800E3800 till 800FFFFF ending right before the stack.

3:To easily find assembly code locations that are within the range of the EXE you can take the PSX ram address of your assembly code and sub 8000F800 from it to find it on the EXE. This will generally only work for non dynamic memory, however you can still manually find arrays of dynamic memory and modify them to make a call to the new empty space and do all kinds of cool stuff.

4:To apply the patch run the RE3 Modders Edition v1.0.exe in the same folder where "Resident Evil 3 - Nemesis (USA).bin" is located.

© 6th of June 2022 Unicorngoulash, some rights reserved.
Declaration of claiming rights: Modification of the assembly hex opcode(s).
Usage condition: Credits for the ASM hex modification(s)

Game info:

rominfo : Game: Resident Evil 3 - Nemesis (NTSC-U)
ID:SLUS_009.23
File/ROM SHA-1: FCB0CE9B9F2E608A52A8E3A09AA62F0EB9EAFF72
File/ROM CRC32: AE3E7A90

System: PS1
Game: Resident Evil 3 - Nemesis (NTSC-U)
ID:SLUS_009.23
File/ROM SHA-1: FCB0CE9B9F2E608A52A8E3A09AA62F0EB9EAFF72
File/ROM CRC32: AE3E7A90