An article on the historical past of EPROMs within the Soviet Union by [Vladimir Yakovlev] over at The CPU Shack Museum caught our consideration. It’s half certainly one of a collection on the subject, and walks you thru the earliest Soviet EPROMs households.

The primary of which, from the Seventies, is the K505RR1 developed and manufactured in Kiev, equal to the first-generation Intel 1702A. It might maintain 2048 bits, organized as 256×8, and supplied a whopping 20 reprogramming cycles and information retention of 5000 hours.

The narrative proceeds to introduce a number of subsequent generations, design amenities, manufacturing methods, and consultant chip examples. Just a few tidbits — in contrast to Western EPROMs, the Soviets managed to place quartz home windows in plastic packages (see the KP573 household).

Along with the frequent grey or white, in addition they used completely different terracotta coloured ceramic packages. An odd ceramic flat-pack EPROM is proven, and likewise some EPROMs whose dies have been painted over and re-badged as OTP chips.

Intel started producing EPROMs in 1971 as reported by the inventor, Intel’s Dov Frohman-Bentchkowsky, in Electronics Journal’s 10 Could version (pg 91). We discovered, amongst different issues, that the 1701 didn’t have a quartz window, however might nonetheless be erased by publicity to X-rays. A pleasant phrase of warning — searching electronics commercials from 50 years in the past can simply eat your complete morning.

As soon as the package deal is sealed, data can nonetheless be erased by exposing it to X radiation in extra of 5×10⁴ rads, a dose which is well attainable with industrial X-ray mills.

To dig deeper, try the CPU Shack’s write-up on the historical past of EPROMs normally, and a chunk we wrote in 2014 concerning the historical past of house computer systems behind the Iron Curtain.