JAMMArcade.net – Page 194

AAA16K4P RAM chips

General, Technical Info Comments Off

Mar 082014

A few weeks ago there was a post on KLOV asking what these chips were.
One of the replies to this was that they might be a PAL chip so my attention was caught.
I managed to borrow a PCB pretty quickly and determined that this was not a PAL chip.
A few users had already mentioned that the manufacturer made RAM chips and after doing some circuit drawing I found what type of RAM it is.
If you ever need to find a replacement for the above chip then look for MB81C68.

DOWNLOAD DATASHEET

Asterix PAL dump added

PAL Updates Comments Off

Mar 062014

caius has dumped the 054253A labelled PAL chip from his Asterix PCB in response to a request on a couple of forums.

Thank you very much to caius

Namco System 1 SYS87A-C tested

PAL Updates Comments Off

Mar 042014

Today I got my Splatter House up and running and also managed to test the PAL I dumped.
SYS87A-C is fully working.

Splatterhouse repair log #1

PCB Repair Logs, Repair Logs 1 Response »

Mar 042014

Picked up a known faulty PCB of Splatter House a bit back.
At first it didn’t boot at all.
First up I found a 6809 CPU with some dead address lines. I replaced this but still no boot, this ended up being a dodgy socket connecting the CPU board to the ROM board.
NOTE: I found all 3 CPU’s need to be running or the board sits in a reset loop.

So, once it was booting I had graphics faults.

Only two of the tile ROM’s were ever getting selected. I traced these back to the CUSTOM chip CUS123 on the ROM board. I had no choice but to find a replacement chip.

Ended up buying a whole new ROM board that contained Pac-Mania ROM’s and had a missing OP-AMP.
Transferring all the ROM’s and the missing chip over fixed everything.

CPS2 motherboard PAL dump

PAL Updates Comments Off

Mar 032014

caius has dumped one of the missing CPS2 motherboard PAL chips marked BGSA1. Not sure how or why ive missed this in the past but its here now and I have tested it.
There is one last remaining PAL chip to dump but this is a registered device so we will have to wait for a bit longer before having a dump of that one.

Thanks to caius

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