Playing with HP2640B

Brent Hilpert bhilpert at
Tue Dec 5 15:36:38 CST 2017

On 2017-Dec-05, at 1:20 PM, Brent Hilpert via cctalk wrote:

> On 2017-Dec-05, at 1:08 PM, Mattis Lind wrote:
>> 2017-12-05 20:44 GMT+01:00 Brent Hilpert via cctalk <cctalk at>:
>>> On 2017-Dec-05, at 9:14 AM, Mattis Lind via cctalk wrote:
>>>> 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.
> The ref did specify it as TTL, so yes, bipolar.

Oh, as for being PROM vs ROM, I'm just going by the way things are listed in the ref.
It lists different 27Sxx devices under PROM vs ROM,
for example 27S180, 27S181 are 1024*8 listed under PROM, but 27S80, 27S81, 27S82, 27S83 are 1024*8 listed under ROM.
It's possible they're mis-listed of course, but manufacturers often did make equivalent devices as both fusible and mask,
I don't know what AMD did for series names in that regard.

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