3 Feb
2006
3 Feb
'06
12:05 p.m.
Hey, so I'm glad that I read a web page (can't remember the URL,
sorry... linked from the Nike Missile site, I think) about
refurbishing deteriorated parts in old machines. I bought a 2648A
main unit (would love a keyboard for it, if anyone has an extra) and
opened it up last night. The tape drive capstans have turned to a
puddle of goo! So I figure that if I ever want the tape drive to be
in working order, that I need to:
i) remove the goo
ii) recreate/replace the capstan
Does anyone have a unit with an intact capstan that could give me
physical dimensions? I doubt anyone has a repair kit that would
include the capstan, but that would certainly be welcome! Aside from
the capstans and a little dust inside the case, the internals look
fine. The case has a small crack in one corner, but otherwise appears
in typical condition for its age. This thing is basically a
microcomputer... when I used them back in 1979, I had no idea that
there was this much electronics inside the thing!
I do have the user manual from bitsavers, but it doesn't go into
repair stuff, just installation (which is how I figured out how to
open the case) of options.
As always... thanks!
--
"The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ:
<http://www.xmission.com/~legalize/book/>
Pilgrimage: Utah's annual demoparty
<http://pilgrimage.scene.org>
3 Feb
3 Feb
12:05 p.m.
Check the archives for messages about HP-85 repairs. They use the same tape
drive and this has been discussed numerous times.
Joe
At 01:05 PM 2/3/06 -0700, you wrote:
Hey, so I'm glad that I read a web page (can't
remember the URL,
sorry... linked from the Nike Missile site, I think) about
refurbishing deteriorated parts in old machines. I bought a 2648A
main unit (would love a keyboard for it, if anyone has an extra) and
opened it up last night. The tape drive capstans have turned to a
puddle of goo! So I figure that if I ever want the tape drive to be
in working order, that I need to:
i) remove the goo
ii) recreate/replace the capstan
Does anyone have a unit with an intact capstan that could give me
physical dimensions? I doubt anyone has a repair kit that would
include the capstan, but that would certainly be welcome! Aside from
the capstans and a little dust inside the case, the internals look
fine. The case has a small crack in one corner, but otherwise appears
in typical condition for its age. This thing is basically a
microcomputer... when I used them back in 1979, I had no idea that
there was this much electronics inside the thing!
I do have the user manual from bitsavers, but it doesn't go into
repair stuff, just installation (which is how I figured out how to
open the case) of options.
As always... thanks!
--
"The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ:
<http://www.xmission.com/~legalize/book/>
Pilgrimage: Utah's annual demoparty
<http://pilgrimage.scene.org>
12:35 p.m.
In article <E1F57B0-0007Ox-00 at xmission.xmission.com>,
Richard <legalize at xmission.com> writes:
[...] I bought a 2648A
main unit (would love a keyboard for it, if anyone has an extra)
OK, serendipity strikes again. In contacting another place in Boise
that had a 2648A w/keyboard, they had another keyboard, so I don't
need a 2nd KB.
I'd still like to hear about capstans though. Does anyone have
experiences to share in addition to the one online at the Computer
History Museum?
--
"The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ:
<http://www.xmission.com/~legalize/book/>
Pilgrimage: Utah's annual demoparty
<http://pilgrimage.scene.org>
12:52 p.m.
On 2/3/2006 at 1:35 PM Richard wrote:
I'd still like to hear about capstans though. Does
anyone have
experiences to share in addition to the one online at the Computer
History Museum?
Not to put too much of fine point on it, but are we talking about capstans
or pinch rollers? I always thought that the capstan was the hard steel
driven shaft and the pinch roller was the soft larger roller that pressed
the tape against the capstan. At least in the nautical sense of the word,
this would seem to make better sense.
At any rate, would any of the commercially available replacement parts for
VCRs or audio tape do the job?
Cheers,
Chuck
1:13 p.m.
On 2/3/2006 at 1:35 PM Richard wrote:
If it's the sort of drive I think it is (alas I don't have this HP
terminal, wish I did...), it works like a QIC tape drive. The motor
spindle has a rubber wheel on the end (this is normally called the
capstan), this turns a hard roller (normally called the drive puck) in
the catrridsge, which then moves the tape by an endless belt that runs
between the 2 spools of tape. We had a discussion some months back about
how this actually tensions the tape (I understood it in the end, it
depends on the fact hat the belt stretches slightly).
The is no capstan/pinch roller like in an audio tape recorder [1]. The
roller that fails is the rubber coated one on the motor spindle, part of
the drive. I have worked on 2 HP tape drives like this. One is the type
used in the HP85 computer. It has a PCB fixed to the back with an HP
custom chip on it. The other is the one used in the HP9815, HP9825,
HP9845, etc computers. It has a PCB attached by wires with a few standard
ICs on it (a TTL decoder chip, 2 or 3 op-amps).
[1] My HP9830 has a built-in tape drive that takes tapes that look like
audio compact cassettes. But there's no pinch roller and capstan, the
only drive is to the spools. And I amp pretty sure this is nothing like
the drive in said HP terminal.
-tony
I'd still like to hear about capstans though.
Does anyone have
experiences to share in addition to the one online at the Computer
History Museum?
Not to put too much of fine point on it, but are we talking about capstans
or pinch rollers? I always thought that the capstan was the hard steel
1:24 p.m.
On 2/3/2006 at 9:13 PM ard at p850ug1.demon.co.uk wrote:
If it's the sort of drive I think it is (alas I
don't have this HP
terminal, wish I did...), it works like a QIC tape drive.
Ah, okay--that makes sense if it is. A couple of months ago, someone
posted a link to a fellow who rebuilds these things "like new" quite
reasonably. Mostly, he does audio and video work, but there's no good
reason that he can't do the HP capstan. A google may turn him up.
Cheers,
Chuck
1:37 p.m.
In article <200602031324090238.5881D0CF at 10.0.0.252>,
"Chuck Guzis" <cclist at sydex.com> writes:
On 2/3/2006 at 9:13 PM ard at p850ug1.demon.co.uk
wrote:
Do you remember the thread subject?
--
"The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ:
<http://www.xmission.com/~legalize/book/>
Pilgrimage: Utah's annual demoparty
<http://pilgrimage.scene.org>
If it's the sort of drive I think it is (alas
I don't have this HP
terminal, wish I did...), it works like a QIC tape drive.
Ah, okay--that makes sense if it is. A couple of months ago, someone
posted a link to a fellow who rebuilds these things "like new" quite
reasonably. Mostly, he does audio and video work, but there's no good
reason that he can't do the HP capstan. A google may turn him up.
2:20 p.m.
On 2/3/2006 at 2:37 PM Richard wrote:
Do you remember the thread subject?
No, but for some unexplained reason, I set a bookmark:
http://www.terrysrubberrollers.com/
Cheers,
Chuck
3:04 p.m.
In article <200602031420070771.58B50FF2 at 10.0.0.252>,
"Chuck Guzis" <cclist at sydex.com> writes:
No, but for some unexplained reason, I set a bookmark:
http://www.terrysrubberrollers.com/
Sweet. It looks like if I can find the appropriate dimensions for
this that he could make an appropriate replacement. Then the next
major mission would be to find media for these tape drives. I suppose
I can get an HP catalog number out of the user's manual to start the
search.
--
"The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ:
<http://www.xmission.com/~legalize/book/>
Pilgrimage: Utah's annual demoparty
<http://pilgrimage.scene.org>
12:13 p.m.
At 04:04 PM 2/3/06 -0700, you wrote:
In article <200602031420070771.58B50FF2 at 10.0.0.252>,
"Chuck Guzis" <cclist at sydex.com> writes:
Don't bother with the old HP tapes. I've never seen a one that worked
more than a couple of days, even NOS ones. And I've tried dozens of them. I
even got a hold of a SEALED case of 100 new sealed tapes and even those
were useless. The old DECassette tapes hold up pretty good and some of the
old 40Mb DC 2 something,something,something tapes used in the early PC
tape drives will also work in the HPs and about half of them that you find
are good. Again this has been covered extensively on this list and should
be in the archives.
Joe
No, but for some unexplained reason, I set a
bookmark:
http://www.terrysrubberrollers.com/
Sweet. It looks like if I can find the appropriate dimensions for
this that he could make an appropriate replacement. Then the next
major mission would be to find media for these tape drives. I suppose
I can get an HP catalog number out of the user's manual to start the
search. --
"The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ:
<http://www.xmission.com/~legalize/book/>
Pilgrimage: Utah's annual demoparty
<http://pilgrimage.scene.org>
5 Feb
5 Feb
2:40 a.m.
On Fri, 3 Feb 2006, Joe R. wrote:
Don't bother with the old HP tapes. I've
never seen a one that worked
more than a couple of days, even NOS ones. And I've tried dozens of them. I
My old ones (over 20 years old) work flawlessly. And my NOS ones (3M) work
nicely, too. I use them regularly to load some simple programs into a
HP1000 system or to transfer files between HP1000 and UNIX.
even got a hold of a SEALED case of 100 new sealed
tapes and even those
were useless. The old DECassette tapes hold up pretty good and some of the
old 40Mb DC 2 something,something,something tapes used in the early PC
tape drives will also work in the HPs and about half of them that you find
are good. Again this has been covered extensively on this list and should
be in the archives.
?!?!?
The 40MB cartridges (DC-2000) and up do *not* work in those HP drives
because they are too big. The tape's 0.25" in these cartridges (QIC), the
tape used with the HP drives is called DC-100 and its tape is much
smaller (about half the height). A DC-2000 or so called QIC-80 cartridge
won't even fit mechanically into a HP drive.
On the other hand I would be very happy if someone gave me 100 new or used
DC-100 tapes; they are *very* rare, at least where I am. The only thing
you have to do with tapes that haven't been used for a long time is to
unstick the belt from the spools by heating the cassette. After that they
work just fine.
Christian
4:31 p.m.
In article <Pine.LNX.4.61.0602051131100.16749 at linuxserv.home>,
Christian Corti <cc at corti-net.de> writes:
On Fri, 3 Feb 2006, Joe R. wrote:
Maybe the issue in question then isn't the tape, but that the drive is
out of alignment. When a floppy is out of alignment, it won't matter
if you put brand new disks in them, it won't work properly.
The service docs and technical docs for the tape drive are on
<http://www.hpmuseum.net>
--
"The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ:
<http://www.xmission.com/~legalize/book/>
Pilgrimage: Utah's annual demoparty
<http://pilgrimage.scene.org>
Don't bother with the old HP tapes.
I've never seen a one that worked
more than a couple of days, even NOS ones. And I've tried dozens of them. I
My old ones (over 20 years old) work flawlessly. And my NOS ones (3M) work
nicely, too. I use them regularly to load some simple programs into a
HP1000 system or to transfer files between HP1000 and UNIX.
6 Feb
6 Feb
3:51 p.m.
Maybe the issue in question then isn't the tape,
but that the drive is
out of alignment. When a floppy is out of alignment, it won't matter
if you put brand new disks in them, it won't work properly.
Eh?
If a floppy drive is out of alignment (this generally means 'radial
alignment'), it will read its own disks. You can take a bulk-erased disk,
format it, rite to it, and read it. What you can't do is use that disk in
a correctly-aligned drive, or use disks from a correctly aligned drive in
an incorrecetly aligned one.
In fact, if you are repairing a floppy drive, you get it working on a
blank disk first. That verifies that the drive is capable of working
correctly. Only then do you put an alignment disk in and do the
adjustments. If you put the alignment disk in from the start, there's a
chance you'll ruin the alignment disk (maybe the write circuit is
permanently enabled due to an electronic fault).
-tony
23 Feb
23 Feb
2:19 p.m.
Found this today, thought I'd share:
<http://hp9825.com/html/dc100_tape.html>
--
"The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ:
<http://www.xmission.com/~legalize/book/>
Pilgrimage: Utah's annual demoparty
<http://pilgrimage.scene.org>
5 Feb
5 Feb
2:53 a.m.
The trick with old tapes (incl. HP-tapes) is :
You have to heat them in the oven to about 55-60 degrees Celcius
and leave them for about 2 to 3 hours.
Then when the tape is yet warm carefully roll the drivewheel.
After this there is a reasanable change that you can use the tapes.
It is a old trick from the audio world.
Otherwise you have to cut the bad part out and fix the tapes.
Gr. Rik
----- Original Message -----
From: "Tony Duell" <ard at p850ug1.demon.co.uk>
To: <cctalk at classiccmp.org>
Sent: Friday, February 03, 2006 10:13 PM
Subject: Re: HP2648A tape drive capstans
On 2/3/2006 at 1:35 PM Richard wrote:
If it's the sort of drive I think it is (alas I don't have this HP
terminal, wish I did...), it works like a QIC tape drive. The motor
spindle has a rubber wheel on the end (this is normally called the
capstan), this turns a hard roller (normally called the drive puck) in
the catrridsge, which then moves the tape by an endless belt that runs
between the 2 spools of tape. We had a discussion some months back about
how this actually tensions the tape (I understood it in the end, it
depends on the fact hat the belt stretches slightly).
The is no capstan/pinch roller like in an audio tape recorder [1]. The
roller that fails is the rubber coated one on the motor spindle, part of
the drive. I have worked on 2 HP tape drives like this. One is the type
used in the HP85 computer. It has a PCB fixed to the back with an HP
custom chip on it. The other is the one used in the HP9815, HP9825,
HP9845, etc computers. It has a PCB attached by wires with a few standard
ICs on it (a TTL decoder chip, 2 or 3 op-amps).
[1] My HP9830 has a built-in tape drive that takes tapes that look like
audio compact cassettes. But there's no pinch roller and capstan, the
only drive is to the spools. And I amp pretty sure this is nothing like
the drive in said HP terminal.
-tony
I'd still like to hear about capstans though.
Does anyone have
experiences to share in addition to the one online at the Computer
History Museum?
Not to put too much of fine point on it, but are we talking about
capstans
or pinch rollers? I always thought that the capstan was the hard steel
3 Feb
3 Feb
1:36 p.m.
In article <200602031252020065.586468DF at 10.0.0.252>,
"Chuck Guzis" <cclist at sydex.com> writes:
Not to put too much of fine point on it, but are we
talking about capstans
or pinch rollers?
I'm probably calling them the wrong thing through ignorance and
assumptions! :-)
I believe you are correct based on this picture:
<http://www.lenoxx.com/manuals/CD101/Image74.gif>
So yes, its the pinch roller that looks like a pile of goo on a
spindle :-)
At any rate, would any of the commercially available
replacement parts for
VCRs or audio tape do the job?
As you can see, I'm so much of a n00b that I can't even name the parts
properly, so I'm not one to answer that! :-)
--
"The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ:
<http://www.xmission.com/~legalize/book/>
Pilgrimage: Utah's annual demoparty
<http://pilgrimage.scene.org>
1:07 p.m.
opened it up last night. The tape drive capstans have
turned to a
puddle of goo! So I figure that if I ever want the tape drive to be
THis is a well-known problem on most old HP machines. I've repaired many
handhelds (the card reader roller fails the same way), the rollers in my
9100Bs, 9810, etc. I've not yet done this sort of drive, though.
There have been several comments on web sites about repairing similar
drives. Look back through the archives on http://www.hpmuseum.org/ for
some ideas.
I don't know if this drive is similar to any other HP unit (is there a
part number on the PCB wired to the mechanism?) but I would guess ideas
for the 9815/9825/9835/9845 or the HP85 might be applicable.
in working order, that I need to:
i) remove the goo
ii) recreate/replace the capstan
Does anyone have a unit with an intact capstan that could give me
physical dimensions? I doubt anyone has a repair kit that would
include the capstan, but that would certainly be welcome! Aside from
If it's like the 9815/9825 one, then the smallest FRU was the complete
drive, alas. The do come apart, although it can be hard to remove the
capstan from the motor spindle (the grub screws put burrs on the motor
spindle, and you can't lever it off because of the tachometer disk which
is fairly delicate).
If you think it's similar to either of the drives I've mentioned, I can
talk you through taking it apart.
I do have the user manual from bitsavers, but it
doesn't go into
repair stuff, just installation (which is how I figured out how to
open the case) of options.
You might also find some documentaition on http://www.hpmuseum.net/ (this
is not the same site I mentioned earlier, one is .org, the other .net).
But I don't recall seing a schematic or similar info for any terminal there.
-tony
7190
days inactive
7210
days old
16 comments
6 participants
participants (6)
-
ard＠p850ug1.demon.co.uk -
cc＠corti-net.de -
cclist＠sydex.com -
dr.emiel＠xs4all.nl -
legalize＠xmission.com -
rigdonj＠cfl.rr.com