Playing with HP2640B

[Mattis Lind]

2017-12-05 20:44 GMT+01:00 Brent Hilpert via cctalk <cctalk at classiccmp.org>:

> On 2017-Dec-05, at 9:14 AM, Mattis Lind via cctalk wrote:
> >
> > Looking more into this document revelas that it covers three boards
> > 02640-60009, 02640-60088 and 02640-60112.
> >
> > Now I had the idea of dumping the character ROM as well. But what is a
> AMD
> > 27S82? I cannot really find a datasheet online. From the schematics above
> > it looks not too much off from standard 2716 EPROM with pin 19 (A10) as
> E3
> > , pin 21 (VPP)  as /E1. But my Data I/O 29B does not seem to be
> compatible
> > with 27S82 and as  pin 21 is active low it gives that a 2716 setting in
> the
> > programmer (reader) won't work.
> >
> > Does the 27S82 have any equivalents that I could look up instead in the
> > device list?
>
> FWIW, 27S82 is listed in the 1982 IC Master as
>
>         AM27S82M:   TTL 1024*8 ROM, 275nS access, OC outputs, 24 pin, 5V
> supply
>
> So half the size of a 2716.
> The book lists PROMs and ROMs separately, so it was probably
> mask-programmed.
> (M would be for mil temp going by other AMD numbers.)
>
>
I would think bipolar PROM since rest of the AMD 27S series were bipolar
PROMs. I will check this weekend if I can find an old AMD databook. I do
have the "Schottky and Low-Power Schottky Bipolar memory, Logic and
Interface" somewhere.
https://drive.google.com/file/d/0B-rp4vyPPYu1Z3d6MkxRQ1NlVXc/view?usp=sharing

I traced the card to understand if the board actually matched the
schematics and it did. Pin 18 was NC and the it was possible to read the
chip with my trusty Data IO 29B as a 2732 and just use the first 1024 bytes
out of it.

The resulting files are here for those who like to preserve them:

http://storage.datormuseum.se/u/96935524/Datormusuem/HP2640B/hp2640b-chargen-1816-0612.hex
http://storage.datormuseum.se/u/96935524/Datormusuem/HP2640B/hp2640b-chargen-1816-0613.hex