9 Oct
2015
9 Oct
'15
12:49 p.m.
On 2015-Oct-09, at 10:28 AM, Marc Verdiell wrote:
Glen,
I'm right in the middle of resuscitating an HP7970E (1600 bpi with the HP-IB
interface). The main problem I had so far was the rubber in the reel hubs
had completely fused to the tape reels that were left on the hubs. I had to
disassemble the hub locking mechanism and use lots of careful X-Acto knife
work to separate the two. A few tape rollers were rough or stuck - just
oiled them for now. Then it started to work, I am very surprised. There are
three red switches on the motor control board inside to make the tape go
forward, reverse and fast rewind. So it's pretty easy to test if the
transport works and the motor servos and tension arms move how they are
supposed to.
I had that problem with the stuck reel hubs. Failed to take my own advice-to-self to leave
the reels unmounted and they stuck again, although easier to get off this time as it
hadn't been many years under pressure.
Brent,
Wow, looked at your site, and you actually wrote a HP 2100 cross-assembler?
Nice. Would it work for the HP21MX too? Did you compile it using the command
line tools in XCode?
I had originally written it in a re-targetable cross-assembler in a now-outdated
development environment under MacOS9. Last year rewrote someone else's assembler (C
source) - it should work in any standard C environment. Was using it to re-assemble
HPBASIC.
I'm not familiar enough with the 21MX machines to say what may have been added/changed
from the early 2100's in assembly terms, but it shouldn't be difficult to add to
the assembler. Can send you the source if you wish.
I had a simulator written in the old OS9 environment too, but haven't brought that
into a current state.
Marc
==========================================================
Date: Wed, 7 Oct 2015 13:29:37 -0700
From: Brent Hilpert <hilpert at cs.ubc.ca>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Subject: HP & 800BPI / was Re: Tape cleaner on eBay
Message-ID: <858603D2-2D79-45D6-993C-A8939D996815 at cs.ubc.ca>
Content-Type: text/plain; charset=us-ascii
On 2015-Oct-07, at 12:56 PM, Glen Slick wrote:
I have an 800BPI 7970B in a 2113B rack system.
I've never gotten
around to trying to get it up and running. Are they fairly reliable
drives to get going again? I don't have any other 800BPI drives to
write any tapes to read with it.
On Wed, Oct 7, 2015 at 12:46 PM, Brent Hilpert
<hilpert at cs.ubc.ca> wrote:
Well, the unit here was in pretty good physical
condition as received.
It had a cascading failure in the capstan driver but it was a fairly
straightforward fix.
I think there was one sluggish/partially-seized pulley bearing (freed up
with some oil).
Pretty rugged drives as you know. I wonder about the capstan rubber in the
long term but I think that's about the only thing to worry about on age
alone.
I think bitsavers nowadays has manuals and schematics for the B version as
you have, years ago I had to do some reverse-engineering for the capstan
repair.
This page is over ten years old and needs some updating, but FWIW:
http://www.cs.ubc.ca/~hilpert/e/HP21xx/HP2116CSys/index.html
Note the tape drive repair log page linked there.