HP Integral PC 82971A EPROM/ROM module - anyone have docs?

Tony Duell ard at p850ug1.demon.co.uk
Sat Dec 6 14:08:27 CST 2008

> Thanks Tony, that should be enough info for me to see if I can get the
> card to work.  So the card will take both 27C256 and 27C512.  I have

yes, but all the (EP)ROMs need to be of the same type

> enough 27C256 on hand to stuff the board with those.
> What is the HP marked IC 1820-2311?  Is that the address comparator?

Yes. It's a 25LS2521, which is much the same thing as a 74LS688 (same 
pinout). An 8 bit identity comaprator, here used to enable the card for 
the approrpatie states of the high-order address lines.

> I will have to create the EPROM tools disk and then take a look at
> what info and tools are there.

Let me (us) know how you get on. I've never tried it.


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