I thought I’d share a little known thing about [the 1702 EPROM]. When you erase most eproms they go to FF and the the process of programming discharges the bits that you want to be ’0′ The 1702 worked backwards. Erasing it set the internal bits to 0 then programming it consisted of charging the bits you wanted to be 1. I know this from the first company I worked at as a programmer. The processor we used was the 8008 and the eprom was 1720s. We used KSR33 teletypes with the paper tape punch to produce something that the prolog m900 programmer could read.