[GreenKeys] UGC-136BX EPROMS

[Dave Beck]

As part of the group buy, I was lucky to get one of the famed UGC-136 teleprinters. It's quite a machine, and my thanks to all involved in that purchase. Unfortunately, it didn't work when I received it. I tried reseating the boards and socketed chips, but no go that is until recently.

It has been sitting for 2 years, until recently, when I ran into Eric Moore and his working unit at the Chicago computer show last weekend. His teleprinter worked beautifully, and he was very receptive to helping me get mine going. (What a great guy!) He was willing to swap boards, etc, but since I'm 3 hours away in Wisconsin, we settled on comparing EPROM images from my machine with his. So, I purchased an EPROM programmer, removed all 10 EPROMS and read them. To my surprise, when I re-assembled the machine, it WORKED! Now I've got a working machine. I loaded up a new 3D printed ribbon (Again thanks to you and the Greenkeys  group) and I'm all set!

I want to thank Eric for his offer to help me, and Nick for posting the EPROM images to his website.

My question is, these EPROMs were programmed in about 1995, or 31 years ago. What is the possibility that they will lose their program after this much time? Anyone have experience with this? From what I can see, there is no harm reprogramming them with the same data. It seems some pinball guys do this for their old machines.
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