HP 2100A stuff - info needed

From: Tony Duell <ard_at_odin.phy.bris.ac.uk>
Date: Tue Sep 23 12:41:11 1997

> > With all of the commotion on pdp8-lovers concerning old HP stuff in
> > Michigan, I decided to take a look at what I have. I have no software or
> > paper with my "pile" (no rack, that was kept by the previous owner), so I
> > am basically stupid about the thing. Maybe someone can help.


I also found an HP2100 in a skip (dumpster) about 5 years ago. I was
allowed to rescue it, and it now sits in my workshop awaiting restoration.
Alas I got no manuals at all with it.

[...]

> > 7900A Disk Drive #1527A04334

Is that the RK05-like thing with one removeable pack and 1 fixed platter?
If so, I found one too, but the front casting got mangled when it was
removed from the rack. Alas I didn't get a PSU for it.

> > 2895B Tape Punch #1632A03303 FACIT model 4070
>
> Yep, this is a badge-engineered Facit paper-tape punch.

A useful trick with these is that it's easy to change a couple of
components and slow them down from 75cps to 50cps (the speed they run at
when manually feeding anyway). This allows them to work correctly even
with a worn-out motor brake - since spares are _very_ expensive, and a
working 50cps punch is still quite useful - I do this rather than replace
the brake assy.

> > 2748A Tape Reader #1133A01747 "System Serial 0815F"

Found one of those with the 2100A as well.

> > Inside the 2100A are cards:
>
> [elided]
>
> In row 1, A1 through A9 are the CPU. I am thinking that A9 and maybe
> A8 are options (DMA?), but will need to pull manuals to look.

My machine seems to have the CPU cards (a label on one them says 'FP ROMs
fitted' I think), the memory area is full (although I'm missing one 'over
the top' connector from one of the core boards) and I have a fair amount
of I/O (disk controller, 8 bit I/O, 16 bit I/O, relay card (?), timebase
generator, tty, plotter, etc).

What I don't have is any manuals. I've read the excellent web site, but I
really need the PSU and system schematics. HP can no longer supply them
AFAIK.

> -Frank McConnell

-tony
Received on Tue Sep 23 1997 - 12:41:11 BST