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8296 bad PLA

Bish500

Experienced Member
Joined
Jan 5, 2017
Messages
64
Location
Peterborough, Ontario, Canada
I have a non-functional 8296. The PLA at U5 is super hot as soon as it’s powered up. I’m assuming it’s bad. Does anyone know of a replacement PLA for this machine?

Thanks!
 

Bish500

Experienced Member
Joined
Jan 5, 2017
Messages
64
Location
Peterborough, Ontario, Canada
I’ve been looking at doing that. There’s an article called “How to replace the PLA UE5 in a CBM8296 with a GAL 20V8” written in 2005 by Nicolas Welte that looks promising, but the adapter would be difficult to make. The article is here: http://x1541.de/

I was hoping someone had come across a more ready-made solution. I looked into something called the PLAdvanced which could be used to replace PLAs in the following devices: Commodore 64 (and SX64), 1551 floppy drives, the CBM 6×0, CBM7xo, Commodore 16 (and C116 & plus/4), the CBM 8296 UE5, the CBM 8296 UE6, the P500 U78 and the P500 U88 (and U78).

It looks like it stopped being available in 2018 though.
 
Last edited:

iz8dwf

Veteran Member
Joined
Mar 20, 2017
Messages
810
Location
Italy
Does anyone have the JEDEC files for the two 8296 PLAs? I can program them if I had the JEDEC files and it would be a single chip replacement.

Same here, I can program them too. Also, I can re-compile the equation to make a valid jedec file if the equations are available, or I can reverse engineer the equations if someone has a binary (ROM-like)
dump.
I haven't looked too hard to find these files since so far I haven't made any 8296 repair anyway.
Frank
 

Dave_C78

Veteran Member
Joined
Nov 25, 2017
Messages
1,699
Hi guys, can i download the two ue5 and ue6 pla bin files from zimmer site and burn it on 27c512 eprom with adapter?
Thanks!
 

mister-freeze

Member
Joined
Feb 20, 2008
Messages
33
Location
Munich, Bavaria, Germany
Same here, I can program them too. Also, I can re-compile the equation to make a valid jedec file if the equations are available, or I can reverse engineer the equations if someone has a binary (ROM-like)
dump.
I haven't looked too hard to find these files since so far I haven't made any 8296 repair anyway.
Frank

https://drive.google.com/file/d/10RqxCNOR9oaRIGEmVC70-qaPI0ojySh-/view?usp=sharing

since I don't have any 8296 to test these maps, use at your own risk

Frank

@iz8dwf
Frank,
I would like to use the .jed to burn 8296 PLAs with 82S100/PLS100 Chips. But before I brick them I wanted to ask you the following:
The .bin files from above are exactly the files to create an EPROM PLA Replacement. The pin order of the input and output pins does not correspond to the PLS100-PLD. pin numbering. The PINS were used in a way that the physical position of the Eprom pins fits best.
Did you consider this when creating the .jed's ?
If it helps I can do a bin-dump of the 8296 PLA's with the "correct" pinout.

(And thanks for the video regarding the C64 PLA and the Soviet chip !! I puzzled around for ages but your tip with the 2 missing lines in the DATAIO-Jedec was the solution.The information for the 2 missing lines could well be taken from the jumbled Jedec file).

Many greetings,
Chris
 
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