28 Sep
2021
28 Sep
'21
8:14 a.m.
... and also has many rare ones in stock; reasonable prices, good guy!
On Mon, Sep 27, 2021 at 11:38 PM ben via cctalk <cctalk at classiccmp.org>
wrote:
On 2021-09-27 9:23 a.m., 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)?
Thanks and best regards
Tom Hunter
http://www.eprompro.com/Index.html
Does PROMS.
Ben.