PS1 Disc-Based Game ID

Available in this repository are xdelta patches for PS1 BIOS files that will allow games running off of disc or PSIO to automatically send Game ID data to a MemCard Pro or SD2PSX, as well as a PS1Digital, Retro GEM, and even a BlueRetro receiver, if you have one of these memory cards installed. Game ID data allows these memory cards to auto-select a virtual memory card page for each game you play, and for HDMI mods and BlueRetro to allow for per-game settings. This doesn't require the user to boot any separate software or exploit, plays the nostalgic PS1 boot splash like a regular startup, and should hopefully maintain full software compatibility.

A note on PS1Digital/Retro GEM/BlueRetro support:

In the future, these may be able to support Game ID functionality without needing a specific memory card, but for now, since these devices do not send the required ACK signals when receiving a Game ID command, you must have a MemCard Pro or SD2PSX installed. PS1Digital and Retro GEM are yet to be tested fully.

WARNING- As of the time of publishing these patches have had limited testing on real hardware. Users who wish to test these patches should have an easy way to modify their BIOS back to stock in case something goes wrong.

Supported hardware

• 8bitmods MemCard Pro
• SD2PSX
• If you have either of the above, you should also gain additional functionality with:
  • PSIO
  • PS1Digital/Retro GEM
  • BlueRetro bluetooth receiver

Requirements

• A supported original BIOS dump (.bin format)
• A replacement EEPROM chip for your system's BIOS and an adapter board to match the console pinout
  • SST 39VF040 recommended
  • Order your own boards from OSHPark and flash the chip yourself
  • OR if you want you can try to contact Will at Will's Console Modifications in the UK to ask if he'd be willing to provide a board + flash chip with pre-patched BIOS. Please note that Will has not endorsed this and I have not reached out to him- other providers may hopefully offer options in the future, including some myself once more testing has been performed.
  • All existing adapter boards require your system to have a 32-pin BIOS chip (see Supported Hardware section below for systems that potentially do not have a 32-pin chip)
• If you have blank chips, an EEPROM programmer (The CD-based flasher is deprecated), OR a kind individual selling pre-flashed chips in some capacity.
  • For blank chips, if you have no way of flashing an individual SST 39VF040 chip, you can purchase a FlashCatUSB XPORT plus a TSOP-32 (Type-B) adapter, or use mi213's TL866 adapter (+ a hot air station to remove the flash chip after flashing) for TL866ii family flashers readily available from Aliexpress (or the socketed versions of mi213's boards to avoid needing a hot air station).

Installing replacement BIOS PCB

Note that this is intended for pre-flashed chips.

1) Locate your BIOS chip (IC102) and make sure it is a 32-pin chip (32 marking in one of the corners)

2) Carefully remove the chip with a hot air rework station, or if you do not have one, by clipping the legs of each pin with a pair of sharp flush cutters

3) If you used flush cutters, use your soldering iron to wipe away any leftover feet, and then clean away the old solder with a soldering wick and clean the area with isopropyl alcohol

4) Prepare your adapter PCB by aligning the flash chip as best you can, tacking down one corner with lots of flux and a little bit of solder (I used too much on one side here), checking the alignment for the other side, and tacking down the opposite corner. If alignment looks good, continue to work the rest of the pins, again using a lot of flux and very little solder

5) Check for shorts on any adjacent pins of the flash chip. Most pins on the adapter are next to each other. Bridge your pad for /WE and VCC if necessary, and solder your adapter in place on the PS1 motherboard. Again use lots of flux, and plenty of solder this time (much harder to bridge these pins). Clean the surrounding areas of the motherboard, and the pins on the flash chip with alcohol when you are done.

How to patch your BIOS dump .bin

Apply the supplied xdelta patch file to your original .bin BIOS dump using DeltaPatcher, or another xdelta patching tool.

Final checksums after patching will be (Release v1.0)

Supported firmware

Tested

• SCPH-5502/5552 (PAL)
• SCPH-101 (US)

Untested

NTSC-U/C

• SCPH-1001**
• SCPH-5501
• SCPH-7001/7501 (should work for 7503 and 9001 as well)

NTSC-J

• SCPH-3500**
• SCPH-5000 (may be a bad dump per PSXDEV)
• SCPH-5500
• SCPH-7000 (should work for 9000 as well)
• SCPH-7003 (identical to NTSC-U/C SCPH-5501)
• SCPH-100

PAL

• SCPH-7002/7502/9002
• SCPH-102A
• SCPH-102B

** - Motherboards for these models may contain a 40-pin BIOS chip. I am not currently aware of any readily available replacement PCBs for these units, and the significant pinout differences would necessitate an adapter PCB.

Unsupported firmware

• Requires an alternative code injection point
  • SCPH-1000 (NTSC-J)
  • SCPH-1002 (PAL)
  • SCPH-3000 (NTSC-J)
• Unverified dumps (per PSXDEV)
  • SCPH-5903 (NTSC-J?)
  • SCPH-7000W (NTSC-J?)
  • SCPH-7500 (NTSC-J)
  • SCPH-7503 (NTSC-J?)
  • SCPH-9000 (NTSC-J)
  • SCPH-9001 (NTSC-U/C)
  • SCPH-9003 (NTSC-J?)
  • SCPH-102 (PAL)
  • SCPH-102C (PAL)
  • SCPH-103 (NTSC-J?)

You can very likely use any firmware you want on any hardware revision (barring of course special models like the Net Yaroze or other devkits)

Todo

• Additional hardware verification

Special thanks

• nocash for his amazing help with developing this patch and for all his work on no$psx and extensive PSX documentation. This project would not exist without him, and as he is currently forced to stay in a small room with family, I'd highly recommend supporting his Patreon or donating directly if you are able!
• 8bitmods for developing the wonderful MemCard Pro and even offering me an advance unit for testing this patch with!
• megavolt85 for developing and releasing the source for their BIOS patching program, even though it didn't end up working. The source included in earlier releases has been modified by me to remove copyrighted BIOS files and add support for the SST 39VF040 flash chip.
• mi213 for their PS1 Flash BIOS project and for graciously providing BIOS boards and helping with testing. See all their OSHPark uploads here.
• bbsan for developing the SD2PSX, arranging to send one to me for testing, and helping test himself.