PlayStation Development Network

Hello, this is my first install of a MM3 mod chip on a JP PS1 (PU-18, 5500)

https://i.imgur.com/lgIbhN5.jpg

I'm booting to the music CD / memory screen but it doesn't get to the black Playstation logo (2nd screen). I verified it can read an audio CD but no burned roms (TDK, are they junk)?

I found this article https://www.psxdev.net/forum/viewtopic.php?t=3668 and put a logic probe on pin 6 and sounds like its getting a signal.

I burned the MM3 chip myself, I'm using a PIC12F675 with the (JP) 12F629 hex file. Messed with the laser power pot on the cd drive etc. I don't own any original games so I haven't been able to test that.

Stumped.

Hi!

The ROM of the Japanese region has additional checks of the boot sector on the CD. They check the 3D PS logo and the license string (during boot screen 2). These checks are in a shell program, let's just call it SHELL, (which loads the CD PLAYER and MEMORY CARD)

In this case the chip (MM3) only unlocks the CDROM controller (Mechanism Control/ aka Mecon) by sending a fake 'SCEI' sequence to it. But this is not enough to load European and American discs. Only discs with Japanese region boot sector will work.

It is possible to choose one of the solutions to this problem:

- Leave the current MM3 chip and additionally replace the Japanese region BIOS ROM with the American region:
- Leave the current MM3 chip and additionally use a cheat cartridge that allows you to skip booting the SHELL program;
- Leave the current MM3 chip and use discs with a Japanese boot sector (Sony Computer Entertainment Inc.). Before burning an American or European game, you should patch the game image with a Japanese boot loader (I think there was a program called "patchit" that patched the boot sector);
- Keep current MM3 chip and use boot loader like IMPORT PLAYER (with Japanese boot sector of course)

All options above should work, provided MM3 chip is flashed properly and works properly.

- Or rechip the console with PSNEE V8 chip, that can patch additional checks of boot sector on consoles of Japanese region.

But there may be a problem with the lack of diagrams for a particular revision of the motherboard.

Briefly the situation looks like this.

Hey Brill! Thanks for the reply! The rom I'm using is a JP region game, it won't just work with the MM3? Maybe I should've just went the PSNEE route, huh?

There can be a lot of reasons for the failure of work, like:
- Inconsistency of the .hex file with the chip (the chip supports instructions from the hex file)
- Wrong region of flashed .hex file (SCEI, SCEA, SCEE)
- Wrong fuses (sorry, I am not a hardware guy, but they should be set on PIC controllers).
- Bad/wrong soldering.
- Wrong wiring diagram.
- Make sure in the emulator that the CD you launch has the original 3D PS logo (pirates sometimes replaced this logo with their logo models) and the license string says "Sony Computer Entertainment Inc". If the emulator shows something else, such disc will not be loaded.
- Poor CD reading by the CD-ROM drive.

Hard to say what the problem is. Try to flash the controller again and set the fuses correctly first (F series should be a reusable flash). Check the soldering, from testpoints to the chip. Test drive reading, at least on a normal AUDIO CD), it doesn't need a chip to start correctly.

I will investigate these things, thank you Brill!

Update, it plays audio CD's without issue, plays burned audio CD's also. There must be an issue with the way I'm burning these JP roms. I just burned JP region .cue to CDR, or maybe it doesn't like the blank CD's I'm using?

I purchased a new PIC12c508a, flashed Mayumi v4 JP hex, and have the exact same result as before (won't boot past white Sony screen with burned CD). I have a strong feeling this laser is no-good. The replacement is a KSM-440ADM, are these ones on eBay ok or where is a good place to buy a replacement? Ty

The modchip license must match your HC05 licence or it will not boot.