PSX GS/AR remake

[Helder]

As some on you know I've been messing with some retro pcb designs for various projects and my latest is to remake the GS/AR and luckily there is a schematic for it so it makes things alot easier than making it from scratch. Now I have looked at the various chips and have read data sheets and wikis and have determined what they do. The PAL chip is a one time programmable chip like a ROM in a game cartridge and because of this I assume it has some kind of boot code or acts as a bios. The EEPROM chip (1Mbit) is where the actual GS/AR software and codes are stored and using today's flash chip we can actually get 4MByte chip for cheap which would hold tons of codes amongst bigger software. Now I could use some help in finding the parallel port plug that the GS had since I can't find shit about it or any resellers of this adapter, is it a standard pc part easy to find or will it be some custom hard to find adapter?

[Hacc]

Looks like you and someone else had the same idea: http://www.assemblergames.com/forums...rk-3-3-to-Work

Helpful links:

http://web.archive.org/web/199906010...qcommslink.htm
http://gaming.stackexchange.com/ques...harklink-cable
http://www.interesting-devices.com/
http://www.hkems.com/m_main.htm
http://www.pcidatabase.com/

[rimsky82]

Now I could use some help in finding the parallel port plug that the GS had since I can't find shit about it or any resellers of this adapter, is it aa standard pc part easy to find or will it be some custom hard to find adapter?

If you mean the DB25 Parallel port, then http://www.digikey.com/product-searc...%20db25%20plug

...But you probably mean the port that plugs into the PSX. I'm betting it's custom.

Looks like you and someone else had the same idea: http://www.assemblergames.com/forums...rk-3-3-to-Work

That's about N64 Gamesharks.

[Helder]

On Assemblers someone posted a likely fit although it might need a little filing on the edges.

http://www.mouser.com/ProductDetail/...M27M4NtmXns%3d

I will have to get one to try out. Now does anyone know what is stored on that PAL chip? its a write only once chip so it must be programmed before it left the factory.

Source:
http://en.wikipedia.org/wiki/Programmable_array_logic

EDIT:
after looking at a broken PSX GS I have I noticed that the plug I linked is the same ones used by GA/AR and the sides are files down too. I will post some High Definition pictures of the board for anyone else who might need it.

[Mezmorize]

On Assemblers someone posted a likely fit although it might need a little filing on the edges.

http://www.mouser.com/ProductDetail/...M27M4NtmXns%3d

At that price I would try to get cheap GameSharks or Gameboy Boosters such as this one:
http://www.ebay.com/itm/PLAYSTATION-...-/230947063605

[rimsky82]

Now does anyone know what is stored on that PAL chip? its a write only once chip so it must be programmed before it left the factory.

I would imagine it flashes the 1M flash chip. I took apart a clone, and there was a Creative chip in there, but I couldn't find a data sheet on it. There were also these:

TC74HC245AP_07 - Octal Bus Transceiver
TMS29F010 - 1M Flash

[Helder]

Well my GS has 5 chips instead of 4 like the AR schematic I seen and quite a few resistors and what looks like crystal which is for the clock signal I assume.

Chips:

LM78L05ACM - Regulator
AM29F010-120JC - 1Mbit flash
PALCE20V8H-25JC - One time Programmable Array
PIC16C55-RC/SO - Programmable Microcontroller with Low cost RC oscillator
HC245 - octal bus transceivers

I'm curious as to what is programmed on the PIC since all the other chips are on the schematic except the crystal (which looks like it works with the PIC) and extra resistors.

[rimsky82]

I haven't taken apart my GS or GS pro yet, but I know the clone had those three chips, a cap, and about 4 or so resistors. There was even two resistors in place of what appeared to be a spot for a transistor.

[Helder]

Here are some good images I took of the PCB with and without components:

[Hacc]

If you mean the DB25 Parallel port, then http://www.digikey.com/product-searc...%20db25%20plug

...But you probably mean the port that plugs into the PSX. I'm betting it's custom.



That's about N64 Gamesharks.

I removed the link. I got a bit carried away looking up stuff. :P

[Helder]

I got some info on the components like the resistors and cap values, now I will make a new schematic based off this version I own and I have also made a custom adapter in Eagle CAD to make it work real nice. I will post info on my progress, but if anyone knows what frequency that cylindrical crystal/oscillator is that would help.