2 Sep
2015
2 Sep
'15
12:50 p.m.
On Wed, Sep 2, 2015 at 8:00 AM, Mike Stein <mhs.stein at gmail.com> wrote:
The ROMs in my 9114s are 09114-15514 REV R.
Need an image? What type/size are they?
There 27128 (16KB).
There are at least five known ROM images for the 9114A/B, and I have
images of two of them. I'm not sure whether 09114-15514 Rev R matches
one that I already have. If you don't mind dumping it, that will be
appreciated. After I've collected a few of these, I'll put them up on
a web page and post the URL to the list, in case anyone else needs
them.
John R. Baker established a precedent for using the contents of the
first two bytes to identify the 9114 firmware revision; I don't know
with certainty that that actually uniquely identifies all revisions.
John wrote an HP-71B program to read the first two bytes over HP-IL.
It should be possible to read the entire contents over HP-IL, but I've
found it easy to pull the EPROM and read it with an EPROM programmer.
John identified five firmware versions:
09114-15514A first two bytes 80 a7 - from 9114A
09114-15514B first two bytes ad fc - probably from 9114A
09114-15515 first two bytes d8 b1 - not sure which model
09114-15516 first two bytes da dc - not sure which model
09114-15521 first two bytes 10 8d - from 9114B
I have images whose first two bytes match the -15514A and -15521,
courtesy of another list member, though I don't know the exact HP P/Ns
that were on the labels. The -15514 image I have has the first two
bytes 80 a7, matching the -15514A in John's list, and has a checksum
(sum of all the bytes, modulo 64K) of 81ce. The -15521 image I have
matches the one in John's list, and has a checksum of 112a.
Some years ago I did a fair bit of study of a disassembly of a 9114A
ROM image, but unfortunately seem to have misplaced the results. I'm
not sure whether I'll do it again. IIRC it had a few more DDT and DDL
commands than were defined in the Filbert (82161A tape drive) command
set, and it also had an entirely different command set which I later
found out was SS/80, for use by the HP 110 Portable and Portable Plus.