Hi Tony,
A few years back you we looking for an IPC HP-82919A Serial interface I
believe?
I was... Then I bought a second IPC on E-bay becuase it contained a
seiral interface (anyhow, a second machine is useful :-)) So I am not
despartely looking for one now.
I have an HP82919A RS232 used and 2x 82927A 512k memory modules new if
you're interested?
IIRC you can quite easily upgrade those RAM boards to 1M each. Certainly
my second IPC came with a 512K RAM PCB that I put the extra chips on and
moved some links.
-tony