John C. Ellingboe wrote:
I never had a problem with all the elephant disk that I used
back then but the absolute worst that I ever saw was a batch of
CDC 5.25" disk that maybe half of them were really useable. I
would take anyones noname disks over them any day.
This brings back memories... I worked at CDC (OK City) when they were
making floppies. The head of the division was Thomas Kamp, one of the
founders of CDC. He had a CDC field engineer come out and install a couple
of CDC drives in his system. This poor kid didn't know who his customer was
and just acted normal. When it came time to run a diagnostic, the kid
removed the CDC diskettes and used a Verbatim. Kamp asked him why, and he
answered (honestly) that the CDC media didn't work on CDC drives. In fact,
he said, nobody can read CDC media.
A few days later, we had guests from Headquarters who went over the story in
great detail. They verifed that CDC drives really couldn't read CDC media.
And proceeded to give one of the nastiest public ass chewings I've everbeen
witness to. Not long after that, CDC media was made by 3M and branded.
Billy
just found an answer to the differences.
there is a partial 7902/9895 manual hp_floppydisk_7209xx.pdf
on dyndns.org that has the history
--
Introduction
This service manual contains service information for the 7902A, 9895K
and the 7902C
flexible disc drives and the controller boards used on the HP 250, 300,
1000, and 3000
series 30 and 33 systems. The following brief history describes the
changes that have taken
place on the disc drives and controller boards and the reasons for the
changes.
The first production model 7902A flexible disc drives were installed in
the HP 250, 300 and
3000 systems. The 7902A drives (P/N 07902-68811) designed for use in
the HP 250 and
the 7902A drives (P/N 07902-60038/07902-60023) for use in the 300/3000
were non-
interchangeable. For this reason a common drive (P/N 07902-67914) was
developed as a
replacement. Refer to service notes HP 250-01 and 7902A-01 for
instructions if one of the
old drives is discovered in the field. In the past, the drive
mechanisms for the 7902A had
been manufactured by Shugart and utilized a tri-compliant head design.
As of September,
1980, this drive was replaced with one using a bi-compliant head design
used on the
7902C.
The drive used on the 9895K is built by CDC and utilizes a
tri-compliant head design. These
drives are not interchangeable between systems because of differences
in drive boards used
on the various systems. The drive boards used on the HP 300/3000
systems are designed
and built by HP and utilize control signals which are non-industry
standard. The drive
boards used on the HP 250 systems are designed and built by both
Shugart and CDC and
utilize industry standard control signals.
The controller board (P/N 45000-66510) used on the old HP 250 systems,
and the control-
ler board (P/N 07902-60024) used on the old HP 300/1000/3000 systems,
were also non-
interchangeable and they both utilized in MC2 micro CPU. A new
controller board (P/N
07902-6652(1) was designed as a replacement for the 45000-66510 board.
If one should
fail in the field, refer to service note 07902A-5A for instructions.
The controller board used
on the old HP 300/1000/3000 systems (P/N 07902-60024) is
interchangeable with the new
controller board (P/N 07902-66501) designed for use with the 7902C. The
new HP 3000
systems no longer use the 7902 disc drives. The 9895A flexible disc
drives will be used in
place of the 7902.
I have the svc docs for the 7902A, which describe
the Amigo protocol in a fair amount of detail.
http://bitsavers.org/pdf/hp/disc/07902-90060_7902svc_May79.pdf
This was the drive used in the HP300 (Amigo)
Was the 9895A a repackaging of the 7902A for the 1000 series?
Does the 9895A still use HP's M2FM encoding format?
There isn't really a picture of the 7902A in the manual.
Apollos tend to be really thin on the ground (manuals and Domain OS
media even more so).
--
I'd still like to scan the material that Bob Shannon has, since, as
you've noticed, DOMAIN docs were tossed when the machines were.
Apollo hardware docs are unobtainium.
I tried contacting the one person who was working on porting NetBSD
to DN3xxx/4xxx, because he had done a LOT of reverse engr and boot
prom disassembly for the machines, but got nowhere. It sounded like
he lost interest in the whole thing, and didn't bother to save what
he had done.
> Any luck on finding the HP-2116A volume 2 manual? ;-)
Sam Wood says he has one, and a core assembly.
I've been asking him about it for months now.
Bottom line is he wants a LOT of money for it
and I have no interest in spending it on that.
As you probably know by now, the 2116 wasn't
designed by HP. The B was a redesign to make
it manufacturable. Docs for the B and onwards
are easy to find (I have probably 6 copies of
the 2116B manuals) Because they had such a
short life, and weren't particularly reliable
there are almost no A's left. The one you turned
up was the first one that still existed that I
had heard about.
Hello all,
Well, I have written a couple of times about the company next door getting
rid of their DEC equipment and prints. The carnage has begun.
I picked up an interesting looking DEC user guide for the MRV-11D prom
module. If any one would like it (I don't have a scanner), let me know.
If there are any specific boards anyone is looking for send me a private
email. The folks next door did have someone stop by and make an offer on the
entire lot, offer was not accepted. The only offer that was considered, was
on the DEC microfiche. I also saved a few sets of IC Masters dates from the
80's and 90's.
Watching the dumpster get filled is depressing.....:>(
Phil
Would it be possible for anyone in San Diego to pick up a couple of smallish
(dual 5 1/4 floppy, 5 1/4 MFM) HP drives for me at IMS Recycling in San
Diego and either re-ship or bring to VCF 8.0? Liberal shipping and beer
allowance provided.
PLEASE REPLY DIRECT - I RECEIVE THE CLASSICCMP DIGEST AND MSGS LAG 2-3 DAYS
Thanks -
Jack
jack.rubin-AT-ameritech.net
Glen, I have the 12821 interface kit manual scanned, don't
appear to have the 9895A scanned. If you can't turn it up
anywhere else, I'll try to borrow a copy from Jeff Moffatt
or Frank McConnell.
The Amigo protocol is documented in Appendix A of
http://bitsavers.org/pdf/hp/disc/09134-90032-Aug-1983.pdf
Tim, if the floppy you were using was in a 10 1/2" box, it
was probably from a third party. Vertical mount drives were
made by Sykes, DSD, AED, and others.
> What in tarnations is an Orbis drive?
Single-sided 8" floppy.
VERY early.
made by Wangco.
I have the product spec. Will put it on
bitsavers in a little while.
