Hello,
I also have a HP 9915A in my possesion. Useless without keyboard and I also
have only documentation for the HP-85.
There is also a
little board inside that has eight sockets, four of which
are populated with 2732 eproms. I am wondering whether this is part of
the
cpu system, or if it is for embedded program
storage like the programmable
rom card for the 85.
The later. There were software developement kits available that let you
write programs in assembler and burn them into EPROMs that plugged into a
HP-85 type plug-in cartridges (called a Hybrid ROM or something like that) or
directly into the 9915. The EPROMs that are in it are probably Matrix and/or
I/O ROM IIRC. That seems to be standard in the 9915s that I'm aware of.
This sounds like they are absolute unobtainium today? I'd better start looking
for a HP-85, only they seem to want quite some money when I see them on
eBay :).
FYI The 9915 doesn't use the HP-85 custom
hybrid processor but uses an
Intel CPU instead! However it does use the HP-85 keyboard processor but only
for the timers that it contains.
Are you sure? I must take a look at my machine then.. What kind of processor
is in there?
I presume that
I can hook up a disk with an hp-ib card (and rom), so it
should be usable once I find a keyboard and appropriate monitor.
Correct. With the keyboard and monitor it should act exactly like a HP-85
(except your's doesn't have the tape drive). But it's a lot easier to find a
HP 85, 86 or 87.
I've always assumed you can't hook up a disk since there is are no disk
routines in ROM?
greetings,
Michiel