14 Jan
2004
14 Jan
'04
2:09 a.m.
Jay,
Thanks for the info. I tried to call you yesterday. The 2114 was one of
the things that I wanted to talk to you about. I have a couple of other
questions. How hard is it to find media for the 7900? (BTW I do have a PT
reader and the 7900 PSU is there and it's all in an original HP cabinet.)
How do I get the 7900 open? Aren't you supposed to apply power get them
open? What is the capacity of the 7900 drive? Where do the IO cables come
out of the 2114? There were NO cables connected to this one. I pulled the
entire chassis out of the rack. There are Buffered TTY boards and such in
the chassis. I suspect that the IO cables plug into those kind of cards and
are supposed to run directly out the back. If so then it's missing the
cables.
BTW here's list of the cards that are in it. Note that the ,s in this
list are as shown on the cards. I'll use ; to separate the items. A1,2;
A1,2; A3,4; A5; A6; A6,7; A8-11; A8-11; A8-11; A8-11; A8-11; A12; A13; A14;
A15; Bus IO; Bffr'd TTY Reg; Dual D/a Conv; Relay Out Reg; Gnd True I/O;
Bffr'd TTY Reg; Multiplex I/O; Time Base Gen.
On the I/O Config Chart it shows "HP Data 70", "TTY 70" and
"Multiplex
IO".
There are only three cards in the IO Expander. They are; A112, A112 and
Univ Intrf.
Joe
At 10:59 PM 1/13/04 -0600, you wrote:
Nice. You really don't see 2114's around
anymore. And 7900's haven't been
common for a long time either - especially if both work.
If this stuff is clean and in a good authentic rack, I would hazzard a guess
of $800, maybe a little more - but then, it all depends on how bad the
person wants it. At one time, I would have easily paid over 1500 for such a
system, today, I would pass on it even at no charge (that may change after I
finish cleaning the basement) :)
One word of caution - on the 7900A drives, there is no carriage lock
mechanism, and the detent only holds the carriage through very VERY minor
jostles. The only way to lock the carriage (right) is with a special
separate (removeable) metal bracket that screws in. Chance are the drive
doesn't have this, it was normally thrown away when the drive was bought and
unpacked. The 7900A is very unlikely to survive a move if the heads are not
restrained, and without that special bracket, you have to do it with wire or
two to three zip ties daisy chained. You can put one end around the front of
the carriage behind the heads, pass the free ends out the airvent holes in
the back, and tie together tightly.
Speaking of the older (and non-multiplatter disc pack) HP drives, the 7900
has a plus (or minus depending on how you look at it). The 7900 uses an
optical sensor (light through a marked glass reticule). All the other drives
use a servo platter - and if you crash a servo platter it's not easy to
get/make another (unless you have the servo formatting boards, a special
servo head, a DSU, and a servo cartridge). The 7900 doesn't have this
sensitivity - if a platter crashes, just replace it and be done with it.
Another pro/con depending on how you look at it. The 7900 has no internal
power supply, it uses a separate rackmount supply. This means the drive runs
cooler inside. Of course, it also takes much more rackspace and will burn up
the amp allotment for your pdu in a rack quick. Do NOT power up that 7900
drive until you disassemble the filter cavity, air hose, air nozzle,
squirrel cage blower fan, etc. and clean inside and out thoroughly!
As I recall, you can run TSB on it (2000/E) if you have a 12920/12921 mux
set in the I/O section. If i remember right, 2000E wouldn't work with
7905/06 and later drives, you need a 7900 (or fixed head drive, lots o luck
there). Unless you have good copies of OS's on 7900A disc pack, you are
definitely going to need a paper tape reader 2748B to do much usefull with
that system. I have a spare in need of minor repair. You will also want an
HP diagnostic library on 7900A disc media for sure.
Jay West
----- Original Message -----
From: "Joe R." <rigdonj(a)cfl.rr.com>
To: <cctalk(a)classiccmp.org>
Sent: Friday, January 02, 1998 12:39 AM
Subject: HP 2114A value??
I have an opportunity to pick up a HP 2114A with the 2155A I/O Expander
and a 7900 disk drive. It was SUPPOSED to be complete and working when it
was pulled out of service. The CPU is FULL of cards but only three cards
in
the IO Expander. What's something like this
worth? The current owner
wants
some of my nicer areospace parts for it. Oh yeah,
There's supposeed to be
a
good size stack of docs with this machine. We
looked today but didn't find
them. Anybody care to tell me more about the computer, expander or disk
drive?
Joe