Programming Bipolar PROMs

Brent Hilpert bhilpert at
Mon Sep 27 13:20:42 CDT 2021

On 2021-Sep-27, at 10:52 AM, Brent Hilpert via cctalk wrote:
> On 2021-Sep-27, at 8:23 AM, Tom Hunter via cctalk wrote:
>> While restoring and repairing a Data General Nova 2/10 I found a bad
>> bipolar PROM on the CPU board. The PROM has open-collector outputs and is
>> organized as 32 words by 8 bits. It appears that one of the open-collector
>> driver transistors is faulty (but it could also be that a fuse has
>> "healed").
>> The part is an Intersil IM5600CP, but these were also made by others, for
>> example Signetics and Philips made the 82S23 and TI and NTE made the faster
>> SN74S188N. Some vendors still sell these parts and there are even a few on
>> Ebay.
>> How do I program these PROMs? I found one somewhat obscure description of
>> the algorithm in the NTE datasheet, but I suspect that each manufacturer
>> had (somewhat) different algorithms.
>> Is there an affordable commercial programmer out there which can program
>> these PROMs?
>> Is there a simple design out there which I could breadboard for a one-off
>> programming job (maybe using an Arduino to control the programming
>> sequence)?

> ...
> Details of the 74S188 programming/burn algorithm is in the 1975 TI Memory Databook for Design Engineers (available at bitsavers) (I expect the 188 is the most likely type you'll find NOS today).

The 82S23 programming algorithm is in the 1975 Signetics Bipolar Memories databook (also on bitsavers).
Looks like it may be a little more complex than that for the 188.

More information about the cctalk mailing list