I've just got an HP82971A RPTOM/ROM module on E-bay...
I thought from the description and part number that this was probably for
the HP Integral PC. And it seems I was right. I've not fully investigated
it yet, but I've traced a few connections from the DIN 41612 connector
through buffers to the EPROM sockets, and they all make sense.
It's a single PCB, normal Integral expansion card size, with the plastic
cover on the bottom and the normal bracket on the back. On the board are
a few TTL chips, mostly buffers, 16 28-pin DIL sockets for the EPROMs, 3
8-poisition DIP switches and not a lot else
From a quick look at the conenctions, it would appear
that the DIP
switches set the start address and also configure the board for one of
3
different types of EPROM (I would guess either 2764, 27128, 27256 or
27128, 27256, 27512). I think all EPROMs have to be the same type. The
sockets are helpfully labelled 0L, 0H up to 7L, 7H.
There's also a 64 pin header socket and mounting pillars for a
daughterboard. The socket iw wired pin-for-pin with the DIN41612 socket
that plugs into the Integral backplane. And the 2 EPROM sockets near the
centre of the bracket are actually individual contacts soldered into the
PCB, thuse making those lower profile than the others and leaving space
for a connector on the daughterboard to come through a hole in the bracket.
I am sure the hardware won't bother me at all, but I don't know the
format of the ROM images. I asusme they appear as a read-only filesystem
to HPUX, and that there are therfore headers in each EPROM containing the
filenames, sizes, start location, etc. Any ideas as to the format of that?
-tony