How to program 82S100 devices - Page 1
Forum section: electronics / general

author: Retirednerd2020
author_rank: Regular Contributor
timestamp: October 14, 2019, 08:38:08 pm
content: I have a few dozen unprogrammed Signetics ceramic dip 82S100 / BXA PLA chips, circa 1987. These were in some of the Commodore computers I believe. Is there an available schematic for rigged-up programmer hardware for these old devices? I looked at the data sheets and could design something to switch the various voltages etc. but don't want to spend too much time to re-invent the wheel. The old commercial programmers that can handle these devices seem pretty expensive. I want to build something out of my junk-box collection with a budget of $0. I have a big junk box. The Goog. searches didn't help me with this one. If I can't get something rigged up in a day or two I'll either toss them or sell them as it is not that important, just something sitting on the shelf I think about from time to time.Thank you for your help.

author: Peabody
author_rank: Super Contributor
timestamp: October 14, 2019, 09:29:58 pm
content: They were used in the C64. I did this way back in the day, and found it to be a major undertaking. You have multiple voltage and timing requirements, and you have to know what equations are to be programmed into the chip. Of course this was before Arduinos, and I ended up needing to flip one Dip switch at a time. Then in the end, there was zero interest in the programmed chips from local Commodore User Groups (there was no Ebay then either). I doubt that would be any different today. In fact, it might be possible to read a good CBM PLA chip as a ROM, and then write that to another ROM that could be used in place of the PLA. Roms of the day wouldn't have been fast enough, hence the need for the PLA, but that might be different now. Anyway, I suspect there is a sufficient supply of good PLAs that can be scavanged from old C64s to supply any current need. But I could be wrong about that. If you look on Ebay for Commodore 64 PLA, you'll see a number of them at pretty fancy prices.I've never seen a schematic for a programmer. I designed my own, but all of that CBM stuff is long since gone.

author: Retirednerd2020
author_rank: Regular Contributor
timestamp: October 14, 2019, 10:03:49 pm
content: Thanks for your comments Peabody. All you said sounds about right. I'm not looking to become rich on these chips. I imagine the market would be the very few purists that don't want to use the EEPROM based replacement options. I just hate to see these cool old chips being wasted. Maybe I'll just put them on Ebay, get $50 or something and someone else can worry about them for a decade or so. They didn't cost me anything as they came with a big box of other stuff I did want.

author: up8051
author_rank: Frequent Contributor
timestamp: October 14, 2019, 10:37:39 pm
content: Here is some information about programming procedure:http://www.idealine.info/CBM/PLS100/82S100_1975.pdf

author: Retirednerd2020
author_rank: Regular Contributor
timestamp: October 14, 2019, 11:08:17 pm
content: Thanks up8051. I have that document or one like it from Signetics. It includes the full procedure for programming them. I think I'm just getting lazy in my old age and am looking for an easier way out on this particular task.