16 Dec
2001
16 Dec
'01
1:26 a.m.
On Dec 16, 9:51, Johnny Billquist wrote:
As has been said before, what do you think manufacturers do at the end of a
production line? Yes, a certain amount of care is required, and certain
things can't tolerate being soaked or being too hot or given too much
mechanical agitation (stress). But how would you deal with a piece of
equipment that was smoke damaged or had been left in the rain or had fallen
in a river or had been infested with vermin or had a can of Coke spilled in
it? I've had to deal with all of those and more over the last two decades,
and washing is the only way.
I don't advocate unneccessary cleaning, but sometimes it's required.
Be careful about that. Allison's warning about ESD is quite real. Don't
even think about a feather duster; at least, not if it's a synthetic one.
--
Pete Peter Turnbull
Network Manager
University of York
On Fri, 14 Dec 2001, Mark Crispin wrote:
> I am appalled that anyone would seriously
consider putting any
electronic
equipment,
much less antiques, in a dishwasher.
I'll have to agree. > It may be alright to (gently!) vaccuum away dust
and deteriorated foam
> rubber, although a feather duster may be more appropriate. I would not
> risk anything else, and certainly not insert anything (including water
or
alcohol) under
the plexiglass shield protecting the core.
Vacuum cleaning (gently!) is about the only thing I'd recommend. 
16 Dec
16 Dec
11:45 a.m.
New subject: was "how to clean".. How did they
or... silly question of the week...
Anyone know how core memory was made?
Did a person string those cores with a needle and
"thread", or was it done by machine?
12:13 p.m.
New subject: was "how to clean".. How did they
Ron Hudson wrote:
or... silly question of the week...
Anyone know how core memory was made?
Did a person string those cores with a needle and
"thread", or was it done by machine?
It was done by hand I think. Mexico comes to mind.
--
Ben Franchuk --- Pre-historic Cpu's --
www.jetnet.ab.ca/users/bfranchuk/index.html
1:37 p.m.
New subject: How did they string core?
It was done by hand I think. Mexico comes to mind.
Some manfacturers did it by hand, some by machine. IBM had core stringing
machines during the S/360 era, for the huge stacks (about 1' by 4') used
in some of the storage units. They also had cores hand strung in the far
East, as the cheap labor was more economical than the robots.
William Donzelli
aw288(a)osfn.org
12:50 p.m.
New subject: was "how to clean".. How did they
It was done by hand with the assistence of
a binoculair microscopes .........................
Sipke de Wal
-------------------------------------------
http://xgistor.ath.cx
-------------------------------------------
----- Original Message -----
From: Ron Hudson <rhudson(a)cnonline.net>
To: <classiccmp(a)classiccmp.org>
Sent: Sunday, December 16, 2001 11:45 PM
Subject: was "how to clean".. How did they
or... silly question of the week...
Anyone know how core memory was made?
Did a person string those cores with a needle and
"thread", or was it done by machine?
9:30 p.m.
On Sun, 16 Dec 2001, Pete Turnbull wrote:
Be careful about that. Allison's warning about ESD is quite real. Don't
even think about a feather duster; at least, not if it's a synthetic one.
ESD should never be ignored, but in the case of computer from the 60s and
70s, ESD is really not an issue. We don't have CMOS, we have old style MSI
TTL here... It is not ESD sensitive. You can literally zap those
circuits, and they will work just fine.
Johnny
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt(a)update.uu.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
On Dec 16, 9:51, Johnny Billquist wrote:
As has been said before, what do you think manufacturers do at the end of a
production line?
They wash them yes. They *don't* put them in a dishwasher. There is a
hughe difference.
On Fri, 14 Dec 2001, Mark Crispin wrote:
> I am appalled that anyone would seriously
consider putting any
electronic
equipment, much less antiques, in a dishwasher.
I'll have to agree. Yes, a certain amount of care is required, and
certain
things can't tolerate being soaked or being too hot or given too much
mechanical agitation (stress).
Which all are things I suspect a normal dishwasher might do.
But how would you deal with a piece of
equipment that was smoke damaged or had been left in the rain or had fallen
in a river or had been infested with vermin or had a can of Coke spilled in
it? I've had to deal with all of those and more over the last two decades,
and washing is the only way.
Grab a bottle of isopropanol, some swabs, and start working.
I don't advocate unneccessary cleaning, but
sometimes it's required.
I'd still never use a dishwasher.
> It may be
alright to (gently!) vaccuum away dust and deteriorated foam
> rubber, although a feather duster may be more appropriate. I would not
> risk anything else, and certainly not insert anything (including water
or
alcohol)
under the plexiglass shield protecting the core.
Vacuum cleaning (gently!) is about the only thing I'd recommend.
4:53 p.m.
Johnny Billquist wrote:
ESD should never be ignored, but in the case of computer from the 60s and
70s, ESD is really not an issue. We don't have CMOS, we have old style MSI
TTL here... It is not ESD sensitive. You can literally zap those
circuits, and they will work just fine.
I don't think a soaking wet board could have a ESD problem.
--
Ben Franchuk --- Pre-historic Cpu's --
www.jetnet.ab.ca/users/bfranchuk/index.html
17 Dec
17 Dec
6:19 a.m.
Ben,
The ESD issue came up after is was suggested that it might be safer to
vacuum a board than to wash it.
The exact opposite is true. Vacuuming creates harmful static electricity -
and can "zap" the board.
- Matt
I don't think a soaking wet board could have a ESD
problem.
--
Ben Franchuk --- Pre-historic Cpu's --
www.jetnet.ab.ca/users/bfranchuk/index.html
Matthew Sell
Programmer
On Time Support, Inc.
www.ontimesupport.com
(281) 296-6066
Join the Metrology Software discussion group METLIST!
http://www.ontimesupport.com/cgi-bin/mojo/mojo.cgi
"One World, One Web, One Program" - Microsoft Promotional Ad
"Ein Volk, Ein Reich, Ein Fuhrer" - Adolf Hitler
Many thanks for this tagline to a fellow RGVAC'er...
2:08 a.m.
I'm not absolutely sure about such things, but, having had to sit through the
annual ESD classes year after year in order to maintain my cert's when I was in
aerospace, ISTR that the "old" TTL was ESD sensitive to a point, and I seem to
remember something about TTL having a threshold of 2KV for ESD sensitivity.
That suggests that while it's not as likely to go poof at the slightest ESD, you
can't "ZAP" it without harming it. Since the "ZAP" that you feel
when reaching
for the doorknob is >50KV, typically, the 2KV would hardly be noticed.
As for that dishwasher, what does it do that thorough washing in water that's
quite hot, and brushing with a brush and using detergents that dissolve flux,
etc, as is often done in PCB manufacture, particularly where rework is
concerned? The "DRY" cycle is unwarranted, but the rest of the operation, so
long as one takes some pains to avoid gettin residual garbage already in the
dishwasher in the connectors, etc, is not likely to hurt the board or its
components, unless you have a leaky relay or some such mechanincal part that
needs protection from water. The tape on some unductors may have a problem with
water, too, so a visual inspection might be warranted. Hot water, soap,
scrubbing, etc, are all common in cleaning and maintaining PCB's.
Dick
----- Original Message -----
From: "Johnny Billquist" <bqt(a)update.uu.se>
To: "PDP8-Lovers" <PDP8-Lovers(a)dbit.com>
Cc: <classiccmp(a)classiccmp.org>
Sent: Monday, December 17, 2001 1:30 AM
Subject: Re: [PDP8-Lovers] Re: how to clean a PDP8/A, dishwasher?
On Sun, 16 Dec 2001, Pete Turnbull wrote:
>
<snip>
...
Allison's warning about ESD is quite real. Don't
even think about a feather duster; at least, not if it's a synthetic one.
ESD should never be ignored, but in the case of computer from the 60s and
70s, ESD is really not an issue. We don't have CMOS, we have old style MSI
TTL here... It is not ESD sensitive. You can literally zap those
circuits, and they will work just fine.
Johnny
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt(a)update.uu.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
6:16 a.m.
Johnny,
I'm offering the suggestion that people try using their dishwasher to give
the computer the bath it really needs. I put (with the exceptions mentioned
in previous posts) all of my boards and control panels through the wash.
Every one of them works after drying. After 10 years of using this method
commercially and in my hobbies, I haven't had a single failure.
And... it's a heck of a lot faster than cleaning by hand.... : )
- Matt
P.S. - TTL logic *IS* static sensitive, just not nearly to the extent that
MOS is.
Matthew Sell
Programmer
On Time Support, Inc.
www.ontimesupport.com
(281) 296-6066
Join the Metrology Software discussion group METLIST!
http://www.ontimesupport.com/cgi-bin/mojo/mojo.cgi
"One World, One Web, One Program" - Microsoft Promotional Ad
"Ein Volk, Ein Reich, Ein Fuhrer" - Adolf Hitler
Many thanks for this tagline to a fellow RGVAC'er...
As has been said before, what do you think
manufacturers do at the end of a
Wrong. One manufacturer I worked for used a commercial Hobart dishwasher
that was modified by an electronics distributer to include racks
specifically made to handle printed circuit boards. This "boardwasher" was
literally a dishwasher. Not a unique setup, either.
You say there is a huge difference. What are the differences? Every
boardwashing setup at every manufacturer I've consulted or been an employee
of used a system that washes boards using higher water pressure and
temperature than your common household dishwasher. If you are referring to
a big difference, then I guess you are right. Your dishwasher is *MUCH*
more gentle for the items being cleaned than the typical commercial
boardwasher.
production line?
They wash them yes. They *don't* put them in a dishwasher. There is a
hughe difference. I don't
advocate unneccessary cleaning, but sometimes it's required.
I'd still never use a dishwasher. 
7:09 a.m.
They wash them yes. They *don't* put them in a
dishwasher. There is a
hughe difference.
I was at a place that actually had a "Maytag BOARDwasher"!
But the font of "BOARD" wasn't an exact match to the font of
"washer", and
peeling it revealed the word "dish" underneath. Nobody could recall where
they had gotten it, and whether the conversion was factory or local.
The racks were different from those in a dishwasher; I never could figure
out what the shelf/rack on the left side of Maytags was for.
8326
days inactive
8327
days old
10 comments
9 participants
participants (9)
-
aw288＠osfn.org -
bfranchuk＠jetnet.ab.ca -
bqt＠update.uu.se -
cisin＠xenosoft.com -
edick＠idcomm.com -
msell＠ontimesupport.com -
pete＠dunnington.u-net.com -
rhudson＠cnonline.net -
sipke＠wxs.nl