HP 9915A (industrial version of HP 85A) - test-drb@ccmp.vtda.org

14 Oct 2002

Hi vp:

...
 From an old 9915A brochure:
Control Signals Interface:
Connector - 15 pin D-subminiature connector, ...(snip)... 
So the Control connector provides some handy ways to restart the 9915
remotely.  I was thinking it might have been a mini-gpio with some
program-readable i/o lines.  Oh well.

...
 The 9915 has sockets for two sets of ROMs: The EPROM
card you mentioned
(which can accomodate up to 32K using 2516, 2716, or 2732 EPROMs) which 
can store user application programs. The second set is a bank of 6
sockets for HP-85 ROM MODULES (white letters). These are the same modules
that plug into the HP Series 80 ROM drawer (HP 82936A). The default
configuration of the 9915 includes the 00085-15003 I/O ROM and the
98151A Program Development ROM (which contains instructions for controlling
the front panel LEDs and switches).

The second bank is located under the expansion card cage. You can
get to them by unscrewing one screw in the back of the 9915 (under
the bottom slot) and one on the Operator Interface card. 
I just found these rom locations as well.  Hidden, but saves a rom drawer
slot.

...
 With just the I/O ROM even if you get an HP-IB card you
will not be able
to use disks, you also need the 00085-15001 Mass Storage ROM for accessing
old-style Amigo drives or the (unobtainable) 00085-15013 EMS ROM that
allows access to the SS-80 drives (e.g. 9122, 9133D/H etc.). 
DOES ANYONE HAVE AN EMS ROM?  It would be nice to get you to dump the
binary for possibly putting it into an eprom.  John Shadbolt (are you on
this list John?) has managed to read an ASM rom, and burn an eprom.  It
then ran from the Prog-rom-module card in and 85.

...
 Given the EPROM card, it may be easier to make a small
ROM emulator board that
...
 allows data to be uploaded via a serial interface.

I thought about a little flash pic or something that could emulate the rom
signals, but that looked non-trivial.  But a configurable 2732 emulator,
hmm, that's probably even been done.  

Problem is, for an 85, it's hard to find the prog-rom card to run an eprom
anyway.  I've been looking at a prog-rom module here, for possible pcb
duplication, but it is stuffed with ttl and a few house-numbered parts.  At
least it does not have a programmed micro or custom "translator" chip like
the serial card.  DOES ANYONE HAVE A SCHEMATIC OR OTHER DOCS FOR THE
PROGRAMMABLE-ROM-MODULE?

...
 The keyboard is simply an 8 by 10 matrix buffered and
debounced, and 
provides 76 cross points. The shift, control and caps lock keys are provided
as dedicated lines. 
Well, I started peeking at the operator interface card in the 9915.  First
off, it looks the the video connector may just go to the edge connector, so
the video may be available (inside) even without the card.

The chips connecting to the keyboard and control connectors were house
numbers, so I just poked the keyboard connector with a scope, to guess at
the matrix i/o lines.  Then, after a bit of playing with a couple of jumper
wires (and the incorrect but usable tv monitor), I have determined most of
the keyboard matrix:

       2    3    4    5    6    7/8     9     10      11    12    13

14   down   8    I    K    M            ,      L       O     9    left
15    up    7    U    J    N            .      ;       P     0    right
16    K4?   6    Y    H    B            /      '       (     -    RPL
17    K3?   5    T    G    V          LIST?   CR?      )     =    -CHAR
18    K2?   4    R    F    C           RUN   PAUSE    CONT   \    ROLL
19    K1?   3    E    D    X            +            -LINE   BS   LOAD
20   K-LBL  2    W    S    Z            -      *       )     (    STORE
21          1    Q    A    SP                  /             ^
22                             SHIFT
23                             CTRL
24                             CAPS-LK

Where the +-*/()^ keys in the bottom right are the numeric pad versions.
The numeric pad number keys were not found.  Pins 7/8 (connected together
inside) are used with lines 22/23/24, but I'm sure don't connect to the
rest of the matrix at all.  There are still a few unknown keys in the main
matrix though.  Pin 25 use is unknown (2.5V).  Pin 1 is chassis ground.

It's too bad this wasn't a parallel interface or something, since an
adapter to a serial keyboard would have been easy.  I suppose an adapter
could use an array of analog-switches to drive the keyboard port, but it
might be easier to find an old keyboard with isolated switch contacts, and
wire it appropriately.  

gil

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