Schematics of FPGA Custom IC replacement board?

Scucci

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I finally got bored enough to start working on some random crap again.

After looking at some of my boards and what they're missing (Gallag addresser board, a couple satellite board for some pacs, a few namco customs, etc etc)... I finally decided it was time to see what I could do about getting some replacement customs for them. ... after seeing the prices for the replacement boards already assembled and programmed I did a quick search for the parts on them and noticed the boards are about $10 each, fully populated, board included, if you could make them yourself. But they're $25 (lowest price I could find) if you wanted to buy them already assembled and programmed.

I have the basic board layout already done, but it doesn't have the "extras" (resistor and capacitors) that are required for full function. As I can't seem to find any information on the programming of these things (EPM7064STC44) I figured I'd ask here.

Does anyone have a full schematic of these things and where can I get the code needed to program them for what I need them for? ... or is that part of the cost and they just haven't released the code for the chips?

CustomStart.png
 
CPLD

I don't recall a spot where the code is freely available. The added cost is most likely all the development that it took to make sure the logic is 100%, cost of the tools to program and test, support, and profit.

Also, stop using 90 degree traces.
 
CPLD
Also, stop using 90 degree traces.

That's a rough in to make sure all the traces could be easily routed without too many vias. When everything is put on the board I'll do something that looks a little better.

It's a shame they haven't released the code. It's not like people wouldn't still order from them if needed, but then again there wouldn't really be anything stopping people from making a competing product.

I just want to make a few for myself because I'm needing over $100 worth of the customs that I could make myself for less than half of that. Que sera... clean it up, put it on the back burner, and wait I guess; that's about all I can do.
 
Some of those custom chips take quite a bit of man hours to reverse engineer. That's where the cost comes from (along with everything else already stated). I'm honestly shocked they are not more!

Edward
 
It would be great to have an open-source version of those CPLD boards. I'd love to have some on hand with a JTAG header that I could reprogram with whatever I need for a particular board during repair / troubleshooting.

I X-rayed and decapped a 00xx Namco custom (284 VRAM addresser) IC just out of curiousity, to see how hard it would be to reverse engineer. It looks like a fairly simple design. The old conformal process makes it tough to make out the circuitry, but with some delayering it's definitely doable.
 
It would be great to have an open-source version of those CPLD boards. I'd love to have some on hand with a JTAG header that I could reprogram with whatever I need for a particular board during repair / troubleshooting.

I X-rayed and decapped a 00xx Namco custom (284 VRAM addresser) IC just out of curiousity, to see how hard it would be to reverse engineer. It looks like a fairly simple design. The old conformal process makes it tough to make out the circuitry, but with some delayering it's definitely doable.

Why would you do that when it's the same as the VRAM Addresser card on Pac Man? Just take the logic layout from that daughter board and reproduce it on the PLD.
 
It would be great to have an open-source version of those CPLD boards. I'd love to have some on hand with a JTAG header that I could reprogram with whatever I need for a particular board during repair / troubleshooting.

I X-rayed and decapped a 00xx Namco custom (284 VRAM addresser) IC just out of curiousity, to see how hard it would be to reverse engineer. It looks like a fairly simple design. The old conformal process makes it tough to make out the circuitry, but with some delayering it's definitely doable.


MAME Source code is your friend....
 
Why would you do that when it's the same as the VRAM Addresser card on Pac Man? Just take the logic layout from that daughter board and reproduce it on the PLD.

Like I said, just out of curiousity to have a look at the process/layout of an IC from that era, and because I had a dead 00xx I could sacrifice.
 
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