HP 2100A stuff - info needed

From: Frank McConnell <fmc_at_reanimators.org>
Date: Sun Sep 21 01:13:08 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.
>
> 2100A Computer #1304A02190 "Option 008"

How to read HP serial numbers, in case you are interested:

  1304A02190

  13 == year, since 1960 (in this case 1973)
    04 == week within year
      A == country of manufacture (A = USA)
       02190 == serial number

The year/week are supposed to be date of manufacture, but I think I
have seen it used to mean date of last revision. Either that or HP
managed to turn out a lot of some things in a week. It's also not
clear whether a change in year/week resets the "counter" portion of
the serial number.

I'm not sure what option 008 is on a 2100A.

> 7900A Disk Drive #1527A04334
> 2895B Tape Punch #1632A03303 FACIT model 4070

Yep, this is a badge-engineered Facit paper-tape punch.

> 2748A Tape Reader #1133A01747 "System Serial 0815F"
> 13215A Disk Drive Power Supply #1435A04338 "Option STD"
> ????? Line Printer #? (Way too buried to investigate)

Hmm, 2613A, 2617A maybe?

> 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.

Likewise I will need to pull manuals to tell you more than obvious
bits (e.g. DISC INT'F 1 and ...2 are how it talks to the 7900A) about
the other things in row 1.

Row 2 is where the memory lives. I am thinking that you have 32KW in
that system; the XYDs should be the X-Y drivers, the SSAs should be
core stacks, and I can't remember exactly what the ID (16K), IDL, or DC
cards do.

I do recall that there is also another flavor of the ID (16K) card for
smaller memory configurations.

There should be five-digit product IDs on each of those cards, most
likely of the form 12ddda, where the "d"s are digits and the "a" is an
alpha character. Those would help me when I have the manuals handy.
Might even help me figure out which ones to pull.

> The processor boards date to 1972, yet others date to the early 1980s.
> Apparently this thing was upgraded (or repaired) several times during its
> life doing secret things.
>
> OK, what do I have? Any input would be helpful.

Well, you have more than I do in the way of hardware. My 2100A was
part of a Fourier analysis system, and so I have some cards that do
some sort of fast crunching on some sort of input signal, but all of
the other I/O and memory was removed. So otherwise I just have the
CPU cards.

But I have manuals. Bug me, I'll pull 'em out and look through them
and try to find out more for you.

w/r/t the rack -- as near as I can tell HP used the same style of 19"
rack for lots of stuff, from various 2100-based systems (including HP
1000s) to the early HP 3000s. I see them from time to time but they
usually have been gutted already and are just empty racks.

-Frank McConnell
Received on Sun Sep 21 1997 - 01:13:08 BST