PS1 modchips - done some research but still confused about what to use?

[Agent24]

I have been greatly enjoying FMCB on my PS2 for a while now, but while it is great, we all know it can't run old PS1 game backups.
So, I wanted to get a modded PS1 and use that, instead.


I couldn't find anywhere to buy a PS1 modchip (easily) but found that it should be possible to make one, as it's simply just a PIC microcontroller.

The problem is, there seems to be about a million different copies of the firmware floating around, and some confusion about the PICs themselves.



The original modchips appear to have used a 12C508 but this is harder to get, and more annoyingly, only OTP (one time programmable)

There is of course the 12F508A but I am not so sure it will work. Someone on this forum says it doesn't work, someone on another forum says it's just fine and you should preferably use it (because it's got a Flash ROM)

Does anyone have any better data on whether the 12F508A will work or not?


As for the firmware, I get the impression (but may be wrong) that they are all much the same but some are stealth and some aren't. I assume that a stealth version would be the best one but the only firmware available for a newer Flash-based PIC (the 12F629) that seems actually known to work, doesn't appear to be stealth at all.

Is there any preference or "best" firmware to use?

[DEMON01]

Just buy pre modded : Stealth PSOne Mod-chip for newer Playstation

[bone]

I programmed a 12F629 and it works fine in my psone 102c it is stealth because it powers off after you boot the game.

[Agent24]

I programmed a 12F629 and it works fine in my psone 102c it is stealth because it powers off after you boot the game.

I could only find one firmware for the 12F629 (Apparently made by GaryOPA in 2008) and he says it doesn't have stealth features. Which firmware did you use?