10 Nov
1998
10 Nov
'98
8:13 a.m.
On Tue, 10 Nov 1998 13:30:09 -0800 (PST) Sam Ismail
<dastar(a)ncal.verio.com> writes:
On Tue, 10 Nov 1998, Daniel A. Seagraves wrote:
I always jumper or otherwise disable those %&$@# things--
they always cause more problems than they solve.
Jeff
___________________________________________________________________
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Then I spot a little tab toward the top of the
case. "Top Cover
Latch"
Aha! Here's what we're after! So, I
unlatch it, and pull the lid
off.
*CLICK!* Whirrrrrrrrr.... *silence*
Seems there's a power interlock in the top cover!
Oops.
Live and learn my young friend. Live and learn. 
10 Nov
10 Nov
12:07 p.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
Seems there's a power interlock in the top cover!
Jeffrey l Kaneko <jeff.kaneko(a)juno.com> wrote:
I always jumper or otherwise disable those %&$@#
things--
they always cause more problems than they solve.
They certainly don't *ALWAYS* cause more problems than they solve.
Some interlocks are very important. For example, some of the interlocks
on vacuum column tape drives are to keep the tape from winding up in a tangle
all over the room (and in an extreme case possibly strangling someone).
Some computers can actually be damaged by operation with interlocks disabled.
For instance, one site disabled the door interlocks on a VAX 8600 while trying
to repair it. This led to the thermal sensors shutting it down. So they
disabled those too. It'll be OK for only a few minutes, right? No, they had
to replace about $15K worth of boards that failed due to overheating. All
because someone thought they knew better than the system designers and could
debug a problem on the cheap instead of calling in a qualified field service
engineer.
I'd suggest defeating interlocks only if you are *sure* you know what
you're doing, not if you *think* you know. In the case of the Alphaserver
that was cited in the earlier email, it is clear that the person opening the
machine did NOT know what was inside it, and it would have been entirely
inappropriate to defeat the interlock.
Eric
11 Nov
11 Nov
12:52 a.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
[Person opening the Alpha had no idea what they were doing, etc.]
He's right - I had no clue what I was up to, and so I really shouldn't have been
poking about. Which is why there's a DEC service engineer on his way here now.
Wonder what he'll think of my DEC toys...
-------
3:35 a.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
Daniel A. Seagraves wrote:
[Person opening the Alpha had no idea what they were doing, etc.]
He's right - I had no clue what I was up to, and so I really shouldn't have been
poking about. Which is why there's a DEC service engineer on his way here now.
I disagree. The best way to learn for someone interested is *doing*.
Misteaks will happen and are a part of the learning process. I *frequently*
used to get in trouble when repairing equipment since I would go in "where
angels fear to tread." HOWEVER, I learned something each time ... including
what to stay away from :)!
3:41 a.m.
New subject: Listserver membership
It occurs to me that if the listserver should be shut down at this location,
we *really* should have a list of members to inform them of the new
location. Does anyone have a list? Hopefully, things will remain as they
are, but it never hurts to be prepared.
6:35 a.m.
New subject: Listserver membership
Yes, there's an emergency classiccmp list setup. Send a "subscribe
classiccmp" message to majordomo(a)nut.net.
-- Doug
On Wed, 11 Nov 1998, Marvin wrote:
It occurs to me that if the listserver should be shut
down at this location,
we *really* should have a list of members to inform them of the new
location. Does anyone have a list? Hopefully, things will remain as they
are, but it never hurts to be prepared.
12 Nov
12 Nov
5:16 p.m.
New subject: Listserver membership
It occurs to me that if the listserver should be shut
down at this location,
we *really* should have a list of members to inform them of the new
location. Does anyone have a list? Hopefully, things will remain as they
are, but it never hurts to be prepared.
You are right.
However, now seems like a good time for me to mention that I've been talking
with David Wall (who works at the computer center here) and Bill Whitson
(the current "moderator") and will almost certainly be filling out the form
to take over the list soon.
I had heard from David (indirectly) that the list has come under scrutiny.
Bill told me the only reason it has continued to exist is that he's extracted
favors from his friends. :)
I keep meaning to post a message to the list... (No, I wouldn't take over the
list without telling everyone, since it's an important matter that concerns
the entire list.) I guess I just did.
In case you're wondering why me, it's simple. I go to the UW, so it's very
easy for me to get privileges on the listproc server here, without having to
move any actual data.
BTW, Bill also told me that he's saved the Web site on CD, so I want to get
that back up too. I'll probably have to use my personal Web space for that,
but I don't have anything else right now anyway.
-- Derek
13 Nov
13 Nov
2:17 a.m.
New subject: Listserver membership
D. Peschel wrote:
Sounds like maybe things will continue as they have in the past. Thanks for
getting involved up there!
It occurs to me that if the listserver should be
shut down at this location,
we *really* should have a list of members to inform them of the new
You are right.
I keep meaning to post a message to the list... (No, I wouldn't take over the
list without telling everyone, since it's an important matter that concerns
the entire list.) I guess I just did. BTW, Bill also told me that he's saved the Web
site on CD, so I want to get
that back up too. I'll probably have to use my personal Web space for that,
but I don't have anything else right now anyway.
It probably wouldn't be a bad idea to have a mirror site, and I think
several people on this list are already doing something similar.
18 Nov
18 Nov
1:55 p.m.
New subject: Listserver membership
On Thu, 12 Nov 1998, D. Peschel wrote:
However, now seems like a good time for me to mention
that I've been talking
with David Wall (who works at the computer center here) and Bill Whitson
(the current "moderator") and will almost certainly be filling out the form
to take over the list soon.
Hurrah for Derek! I have just recieved confirmation from
cac.washington.edu that he has put in the paperwork!
The list is open again!
BC
P.S. A new member wanted to join so I emailed Rebekah Skiver
<bskiver(a)cac.washington.edu> about the problem. (Hi John - hope you are
reading this 8-) She then returned email that Derek had gotten the
paperwork in after signing John on. I thanked her for her support.
I think some others should thank her and David Wall as well as Derek.
Without thier help and support - the list would have been history.
(Besides - when they start scrapping hardware - I think WE should get
first crack at it 8-)
19 Nov
19 Nov
8:10 a.m.
New subject: Listserver membership
Brett,
Hi. I got your email. I have been reading all the letters annd will continue to
do so. When I find one that I can answer I will. I have gone to several web sites
and like the info there. I have many IBM PCjr's. If anyone else plays with these
as a hobby pass my email address on, I do have some tech manuals for it and will
help anyone needing it.
John
Brett wrote:
On Thu, 12 Nov 1998, D. Peschel wrote:
However, now seems like a good time for me to
mention that I've been talking
with David Wall (who works at the computer center here) and Bill Whitson
(the current "moderator") and will almost certainly be filling out the form
to take over the list soon.
Hurrah for Derek! I have just recieved confirmation from
cac.washington.edu that he has put in the paperwork!
The list is open again!
BC
P.S. A new member wanted to join so I emailed Rebekah Skiver
<bskiver(a)cac.washington.edu> about the problem. (Hi John - hope you are
reading this 8-) She then returned email that Derek had gotten the
paperwork in after signing John on. I thanked her for her support.
I think some others should thank her and David Wall as well as Derek.
Without thier help and support - the list would have been history.
(Besides - when they start scrapping hardware - I think WE should get
first crack at it 8-) 
11 Nov
11 Nov
7:58 a.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
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12:07 p.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
Tony Duell wrote:
The first time I repaired a Video Disk player, I made the mistake of
removing the laser section to check some things. It took me three hours to
get the thing aligned again (I didn't have the special alignment fixtures)
by the move and check method. Don't really want to go through that again
:)!
angels fear to tread." HOWEVER, I learned
something each time ... including
what to stay away from :)!
I tend to learn how to do it right the next time - I think. And then the
'next time' comes and I still make a silly mistake.
12:51 p.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
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11:49 a.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
Date: Thu, 12 Nov 1998 02:51:47 +0000 (GMT)
Reply-to: classiccmp(a)u.washington.edu
From: ard(a)p850ug1.demon.co.uk (Tony Duell)
To: "Discussion re-collecting of classic computers"
<classiccmp(a)u.washington.edu>
Subject: Re: Power interlocks (was Re: [OT] Alphaserver Oops!)
> The first time I repaired a Video Disk player, I
made the mistake of
> removing the laser section to check some things. It took me three hours to
> get the thing aligned again (I didn't have the special alignment fixtures)
> by the move and check method. Don't really want to go through that again
> :)!
>
This is okay if you only remove the rails that are only crocked in
their little "v blocks by spring fingers pressure and the carrier
only follows the worm or linear gear pr voice coil. I have done that
so many times on floppy drives, many cdrom drives. Nay on
Split-belt!
Incidentally, I am unimpressed by manuals that try to
limit the sort of
jobs you can do in the field. I'll decide if I can use a 'scope, align
heads, have a clean room to strip an HDA, etc. It may have made sense
when the unit was in production to replace/exchange subassemblies, but it
sure makes life difficult now...
Well, that is true even for senior techs usually don't have right
experience to see something that is not supposed to be bothered on
sensitive machines and manuals was written for that purpose to
prevent mishaps. But it's good to have mistakes.
I did cook few parts, break or threw timing sensitive machines out of
wack. Hehehehe.. Good experience but expen$ive sometimes indeed!
Better break somthing (hopefully not the vital ones or expendables)
so you can make better designer.
-tony
Hey, remember, did many have seen the actual bare package of an
alpha CPU? It DOES have 2 studs on a heatspreader? Woah, heat big
time!
Saw that few times on Microway ad's selling this Alpha motherboards
for AT case? That's where I saw it.
If anyone appoaches a "commerical" machine I bet you that it does
have interlocks for good reasons to prevent blundering techies and
protect both sides on employment and equipment.
Just remember to do that: check for any of those protections after
the machine is shutdown and powered off.
Jason D.
email: jpero(a)cgocable.net
Pero, Jason D.
11:20 p.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
[Alpha Heatsink]
Ours was a 233MHz chip, and it had a heat sink that was huge. It looked
like it WAS screwed right onto the CPU... Maybe when we move the machine
downtown next year I'll pull the side covers off (The F-S guy showed me how.
BTW, it doesn't void our warranty if I poke around inside the Alpha, as long
as I don't smoke anything. He also showed me how to wedge the microswitch
closed with an ink pen.) and have a look at it.
-------
12 Nov
12 Nov
3:08 a.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
jpero(a)pop.cgocable.net wrote:
Actually, it is not okay in this instance. The problem is that the laser
beam goes through a series of prisms, mirrors, and gratings from the time it
leaves the laser, reflects off the disk, and gets back to the photo diode
array. Getting a 20 mil or so beam lined up to close tolerances (5 mils?)
can be a bit tricky on the described path of about 20+". The assemblys I
removed were the mirrors and prisms that reflect the beam onto the disk, and
back through the path to the photo diode array. The alignment can be done
without special equipment/fixtures ... given enough time :).
> The first time I repaired a Video Disk
player, I made the mistake of
> removing the laser section to check some things. It took me three hours to
This is okay if you only remove the rails that are only crocked in
their little "v blocks by spring fingers pressure and the carrier
only follows the worm or linear gear pr voice coil. I have done that
so many times on floppy drives, many cdrom drives. Nay on
12:33 a.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
Date: Thu, 12 Nov 1998 09:08:13 -0800
Reply-to: classiccmp(a)u.washington.edu
From: Marvin <marvin(a)rain.org>
To: "Discussion re-collecting of classic computers"
<classiccmp(a)u.washington.edu>
Subject: Re: Power interlocks (was Re: [OT] Alphaserver Oops!)
jpero(a)pop.cgocable.net wrote:
Actually, it is not okay in this
instance. The problem is that the laser
beam goes through a series of prisms, mirrors, and gratings from the time it
leaves the laser, reflects off the disk, and gets back to the photo diode
array. Getting a 20 mil or so beam lined up to close tolerances (5 mils?)
can be a bit tricky on the described path of about 20+". The assemblys I
removed were the mirrors and prisms that reflect the beam onto the disk, and
back through the path to the photo diode array. The alignment can be done
without special equipment/fixtures ... given enough time :).
I don't mean this one so I go...
That should have been clarified:
The len, all the glass bits, laser and sensor leave it be and often
they're all in one module. No problem removing the whole thing
if only taking the rails off.
Done that so many times just to clean off all the old grease and
relube to revive many cdrom drives ditto removing the spindle motors
to take shorts out.
Jason D.
email: jpero(a)cgocable.net
Pero, Jason D.
6:47 a.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
jpero(a)pop.cgocable.net wrote:
Actually, it is not okay in this instance.
The problem is that the laser
beam goes through a series of prisms, mirrors, and gratings from the time it
leaves the laser, reflects off the disk, and gets back to the photo diode
I don't mean this one so I go...
That should have been clarified:
The len, all the glass bits, laser and sensor leave it be and often
they're all in one module. No problem removing the whole thing
if only taking the rails off.
11 Nov
11 Nov
7:52 a.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
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12 Nov
12 Nov
9:33 a.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
At 06:52 AM 11-11-98 -0800, Daniel A. Seagraves wrote:
He's right - I had no clue what I was up to, and so
I really shouldn't have
been
poking about. Which is why there's a DEC service engineer on his way here
now.
Wonder what he'll think of my DEC toys...
Well, if you get the usual "modern" Digital FS person, he/she won't even
recognize the equipment. About 5 years ago we hosted a DECUS meeting here
at La Trobe and two of us set up an 11/44 running BSD2.11 to celebrate the
25th anniversary of Unix (or some such excuse).
We managed to kill the RL controller and as this was a DECUS event, we were
asked to call FS to come and repair the system whilst charging the call to
a Digital account.
Trying to log the call was interesting ("a PDP-11/44 - I'm sorry we don't
maintain them - are you sure it's a Digital product") and even more fun
when the engineer came out and said something like "hey, I've never seen
one of these before". I just took the board, swapped it, ran diagnostics
(OK, I booted 2.11) and sent him on his way :-)
Huw Davies | e-mail: Huw.Davies(a)latrobe.edu.au
Information Technology Services | Phone: +61 3 9479 1550 Fax: +61 3 9479 1999
La Trobe University | "If God had wanted soccer played in the
Melbourne Australia 3083 | air, the sky would be painted green"
11 Nov
11 Nov
1:40 a.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
Eric Smith wrote:
They certainly don't *ALWAYS* cause more problems
than they solve.
Some interlocks are very important. For example, some of the interlocks
on vacuum column tape drives are to keep the tape from winding up
in a tangle
all over the room (and in an extreme case possibly strangling someone).
Did you mean "an" extreme case (such a case exists) or "the" extreme
case (such a case could exist). Boy, that would make The News of The
Weird and probably The World Weekly News and other tabloids. Would
there be a CERT advisory for that?
7:22 a.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
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9:58 a.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
I'd
suggest defeating interlocks only if you are *sure* you know what
you're doing, not if you *think* you know. In the case of the Alphaserver
Since when has anyone here ever _known_ what they are doing? I ask that
seriously - we all (I hope) think we're doing the right thing, but I for
one am never sure I am not making a mistake.
11:26 a.m.
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11:21 a.m.
New subject: Power interlocks (was Re: [OT] Alphaserver Oops!)
Tony Duell wrote:
Since when has anyone here ever _known_ what they are
doing? I ask that
seriously - we all (I hope) think we're doing the right thing, but I for
one am never sure I am not making a mistake.
I _know_ I'm always making a mistake, so I've learned not to worry
about it too much. I simply try not to make the same mistake the
next time, as I only have so much chronological bandwidth, and if I
repeat a mistake I've wasted time that could be used in learning
from new mistakes. (Anybody who claims never to make
mistakes is
[first] a liar and [second] a liar with a prior conviction and
[third] well, three strikes and you're out).
--
Ward Griffiths <mailto:gram@cnct.com> <http://www.cnct.com/home/gram/>
WARNING: The Attorney General has determined that Alcohol, Tobacco,
and Firearms can be hazardous to your health -- and get away with it.
12:42 p.m.
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9531
days inactive
9540
days old
25 comments
13 participants
participants (13)
-
amirault＠epix.net -
ard＠p850ug1.demon.co.uk -
bill＠chipware.com -
danjo＠xnet.com -
dpeschel＠u.washington.edu -
DSEAGRAV＠toad.xkl.com -
eric＠brouhaha.com -
gram＠cnct.com -
H.Davies＠latrobe.edu.au -
jeff.kaneko＠juno.com -
jpero＠pop.cgocable.net -
marvin＠rain.org -
yowza＠yowza.com