Identification of an HP minicomputer

J. David Bryan jdbryan at
Mon Aug 12 18:54:30 CDT 2019

On Monday, August 12, 2019 at 15:48, Guy Sotomayor Jr via cctalk wrote:

> I´ll see about firing it up and if that goes well (anyone have
> suggestions for this type of mini?) 

You didn't list the cards in the rear I/O cage (the IDs should be on the 
card ejectors).  However, if you have a 12821A HP-IB Disc Interface, you 
could run the standard HP diagnostics, which are quite thorough.  They're 
available here:

You'd also need the 12992J CS/80 Disc Loader ROM, if it's not installed 
(the binary is available at Bitsavers, and the chip is a fairly common 256 
x 4-bit bipolar PROM), a $50 GPIB card for a PC, and Ansgar Kueckes' 
HPDrive program:

...which emulates a cartridge tape drive (among other HP mass-storage 
peripherals).  That setup (12821A card/GPIB card/HPDrive program) also 
opens up the possibility of running some of the HP disc-based operating 
systems without requiring an HP disc or tape drive.

Without removing the CPU, you can't easily tell which loader ROMs are 
installed in sockets on the PCB (there are up to four, with the first being 
a paper tape loader), except by loading each one into memory and comparing 
it to the binary listings in the 12992 manual.

Also, you can't easily determine if any optional firmware instruction set 
PCBs are installed (they mount to the CPU board via standoffs).  Removal of 
the bottom chassis panel is simple, which will reveal the firmware PCBs, 
but the part numbers are on the underside, i.e., facing the CPU board, 
typically requiring their removal from the CPU PCB for identification.

                                      -- Dave

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