Programming Bipolar PROMs

[Jonathan Chapman]

I can do them with the Data I/O 29B and UniPak 2B. Some of the other UniPaks can handle them too. They are one of those devices that most of the newer commercial programmers can't do. I wouldn't call the Data I/O really affordable, though.

If you want to send us a blank we can program it for you, or we probably have some blanks for that part # on hand.

Watch out buying blanks on eBay, they're often pulls and are actually already programmed. Also the yield was not 100% even back in the day, apparently, so buy several to ensure you do get a good one.

Thanks,
Jonathan

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐

On Monday, September 27th, 2021 at 11:23, Tom Hunter via cctalk <cctalk at classiccmp.org> 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)?
>
> Thanks and best regards
>
> Tom Hunter