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Re: IBM's 96 column punch card (was System/3)?

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"Dan Espen" <despen@verizon.net> wrote:
> hancock4@bbs.cpcn.com writes:
>> D_J_E wrote:

[hardware reliability]

>> Ok, but with EAM stuff you could pull out the offending card,
>> visually examine it, and restart things relatively easily.

> A mangled card is easy to fix.  An actual broken EAM machine
> was just as hard to fix as a computer.

>> Not as easily done with electronic computers.  People here have reported
>> using a special fluid and ironing filings to view mag tape contents.

> I've read that iron filings story a couple of times here.
> Never heard the story anywhere else, even a second hand recounting.

I think you'll find the instructions for "developing" mag tape in some of 
the IBM CE manuals.  Especially with the earlly mag tapes which ran at 200 
bpi it wasn't that difficult to read the data using a half-decent magnifying 
glass, although (rather obviously) the difficulty rating went up as 
densities increased.

My recollection is that the IBM procedures instructed the CE to empty a 
sealed cup of very fine iron filings into a (can?) of solvent, then brush 
the resulting suspension onto the tape.

What I can attest to is that tape developer was used when splicing early 2" 
videotape - which was for a while the only way to edit it.  You clamp the 
tape holding one side of the splice oxide-up in a heavy splicing block, 
develop it, locate the center of the video frame boundary using a built-in 
microscope, then clamp the tape in place and cut it with a razor blade. 
Turn a knob that pushes the end of that tape out of the way while 
maintaining its position and repeat the procedure with the tape for the 
other side of the splice.  Now clean off the develper material, raise the 
tape on both sides of the not-yet-created splice, put adhesive splicing tape 
(gummy side up) directly where the splice will be, drop the tape ends onto 
the splicing tape, cut off the ends of the splicing tape, and rub to 
complete the splice.

Not exactly a task that can be done quickly.

And, if the Internet can be believed, you can still buy a ready-made bottle 
of magnetic developer. Look at the site www.magneticdeveloper.com .  No, I 
never heard of them until this evening when I was looking to see if 
Bitsavers had a CE manual that talked about developing tape (as far as I can 
tell, it doesn't).

> That kind of action should not be necessary.  That's what
> backups are for.

I'm guessing that developing tape to look for drive problems went out of 
favor by perhaps the middle 1960s.

Joe 

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Re: IBM's 96 column punch card (was System/3)? Quadibloc <jsavard@ecn.ab.ca> - 2016-04-15 07:16 -0700
  Re: IBM's 96 column punch card (was System/3)? Morten Reistad <first@last.name.invalid> - 2016-04-15 17:16 +0200
    Re: IBM's 96 column punch card (was System/3)? "Rod Speed" <rod.speed.aaa@gmail.com> - 2016-04-21 19:55 +1000
      Re: IBM's 96 column punch card (was System/3)? Stephen Wolstenholme <steve@easynn.com> - 2016-04-21 11:10 +0100
        Re: IBM's 96 column punch card (was System/3)? "J. Clarke" <j.clarke.873638@gmail.com> - 2016-04-21 22:17 -0400
  Re: IBM's 96 column punch card (was System/3)? hancock4@bbs.cpcn.com - 2016-04-15 14:03 -0700
  Re: IBM's 96 column punch card (was System/3)? Walter Bushell <proto@panix.com> - 2016-04-17 10:36 -0400
    Re: IBM's 96 column punch card (was System/3)? Stephen Wolstenholme <steve@easynn.com> - 2016-04-17 15:46 +0100
      Re: IBM's 96 column punch card (was System/3)? Dave Pitts <dpitts@cozx.com> - 2016-04-17 09:52 -0600
    Re: IBM's 96 column punch card (was System/3)? Gerard Schildberger <gerard46@rrt.net> - 2016-04-17 17:18 -0700
      Re: IBM's 96 column punch card (was System/3)? Walter Bushell <proto@panix.com> - 2016-04-22 11:01 -0400
        Re: IBM's 96 column punch card (was System/3)? Ahem A Rivet's Shot <steveo@eircom.net> - 2016-04-26 08:22 +0100
        Re: IBM's 96 column punch card (was System/3)? Ahem A Rivet's Shot <steveo@eircom.net> - 2016-04-26 08:20 +0100
    Re: IBM's 96 column punch card (was System/3)? hancock4@bbs.cpcn.com - 2016-04-19 11:44 -0700
      Re: IBM's 96 column punch card (was System/3)? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2016-04-20 01:36 +0000
        Re: IBM's 96 column punch card (was System/3)? hancock4@bbs.cpcn.com - 2016-04-20 16:58 -0700
          Re: IBM's 96 column punch card (was System/3)? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2016-04-21 03:52 +0000
            Re: IBM's 96 column punch card (was System/3)? hancock4@bbs.cpcn.com - 2016-04-21 12:37 -0700
            Re: IBM's 96 column punch card (was System/3)? Peter Flass <peter_flass@yahoo.com> - 2016-04-21 16:25 -0400
              Re: IBM's 96 column punch card (was System/3)? Dan Espen <despen@verizon.net> - 2016-04-21 17:35 -0400
                Re: IBM's 96 column punch card (was System/3)? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2016-04-21 21:51 +0000
                Re: IBM's 96 column punch card (was System/3)? Dan Espen <despen@verizon.net> - 2016-04-21 20:58 -0400
                Re: IBM's 96 column punch card (was System/3)? Peter Flass <peter_flass@yahoo.com> - 2016-04-22 11:34 -0400
                Re: IBM's 96 column punch card (was System/3)? hancock4@bbs.cpcn.com - 2016-04-22 12:53 -0700
                Re: IBM's 96 column punch card (was System/3)? hancock4@bbs.cpcn.com - 2016-04-22 12:45 -0700
                Re: IBM's 96 column punch card (was System/3)? Peter Flass <peter_flass@yahoo.com> - 2016-04-22 11:34 -0400
                Re: IBM's 96 column punch card (was System/3)? hancock4@bbs.cpcn.com - 2016-04-22 12:55 -0700
                Re: IBM's 96 column punch card (was System/3)? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2016-04-22 22:18 +0000
                Re: IBM's 96 column punch card (was System/3)? hancock4@bbs.cpcn.com - 2016-04-22 12:38 -0700
                Re: IBM's 96 column punch card (was System/3)? "Joe Morris" <j.c.morris@verizon.net> - 2016-04-21 21:21 -0400
                Re: IBM's 96 column punch card (was System/3)? Dan Espen <despen@verizon.net> - 2016-04-21 22:21 -0400
                Re: IBM's 96 column punch card (was System/3)? Anne & Lynn Wheeler <lynn@garlic.com> - 2016-04-21 21:53 -0700
                Re: IBM's 96 column punch card (was System/3)? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2016-04-22 15:22 +0000
                Re: IBM's 96 column punch card (was System/3)? scott@slp53.sl.home (Scott Lurndal) - 2016-04-22 17:55 +0000
                Re: IBM's 96 column punch card (was System/3)? hancock4@bbs.cpcn.com - 2016-04-22 12:31 -0700
                Re: IBM's 96 column punch card (was System/3)? Dan Espen <despen@verizon.net> - 2016-04-23 10:43 -0400
                Re: IBM's 96 column punch card (was System/3)? hancock4@bbs.cpcn.com - 2016-04-23 12:48 -0700
                Re: IBM's 96 column punch card (was System/3)? Peter Flass <peter_flass@yahoo.com> - 2016-04-23 16:21 -0400
                Re: IBM's 96 column punch card (was System/3)? Dan Espen <despen@verizon.net> - 2016-04-23 18:12 -0400
                Re: IBM's 96 column punch card (was System/3)? JimP <solosam90@gmail.com> - 2016-04-23 20:44 -0500
                Re: IBM's 96 column punch card (was System/3)? Huge <Huge@nowhere.much.invalid> - 2016-04-24 09:09 +0000
                Re: IBM's 96 column punch card (was System/3)? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2016-04-25 15:08 +0000
                Re: IBM's 96 column punch card (was System/3)? hancock4@bbs.cpcn.com - 2016-04-25 13:39 -0700
                Re: IBM's 96 column punch card (was System/3)? Dan Espen <despen@verizon.net> - 2016-04-23 18:07 -0400
                Re: IBM's 96 column punch card (was System/3)? hancock4@bbs.cpcn.com - 2016-04-25 13:48 -0700
                Re: IBM's 96 column punch card (was System/3)? Dan Espen <despen@verizon.net> - 2016-04-25 17:33 -0400
                Re: IBM's 96 column punch card (was System/3)? "Joe Morris" <j.c.morris@verizon.net> - 2016-04-25 19:47 -0400
                Re: IBM's 96 column punch card (was System/3)? Dan Espen <despen@verizon.net> - 2016-04-25 22:56 -0400
                Re: IBM's 96 column punch card (was System/3)? Jon Elson <jmelson@wustl.edu> - 2016-04-26 17:51 -0500
              Re: IBM's 96 column punch card (was System/3)? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2016-04-21 21:40 +0000
              Re: IBM's 96 column punch card (was System/3)? Walter Bushell <proto@panix.com> - 2016-04-21 22:31 -0400
                Re: IBM's 96 column punch card (was System/3)? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2016-04-22 15:22 +0000
              Re: IBM's 96 column punch card (was System/3)? Stephen Wolstenholme <steve@easynn.com> - 2016-04-22 07:15 +0100
                Re: IBM's 96 column punch card (was System/3)? scott@slp53.sl.home (Scott Lurndal) - 2016-04-22 14:44 +0000
              Re: IBM's 96 column punch card (was System/3)? hancock4@bbs.cpcn.com - 2016-04-22 12:16 -0700
                Re: IBM's 96 column punch card (was System/3)? Peter Flass <peter_flass@yahoo.com> - 2016-04-22 17:10 -0400
              Re: IBM's 96 column punch card (was System/3)? Gene Wirchenko <genew@telus.net> - 2016-04-22 22:38 -0700
                Re: IBM's 96 column punch card (was System/3)? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2016-04-23 16:28 +0000
          Re: IBM's 96 column punch card (was System/3)? Peter Flass <peter_flass@yahoo.com> - 2016-04-21 12:35 -0400
            Re: IBM's 96 column punch card (was System/3)? hancock4@bbs.cpcn.com - 2016-04-21 12:41 -0700
              Re: IBM's 96 column punch card (was System/3)? Peter Flass <peter_flass@yahoo.com> - 2016-04-21 16:25 -0400
                Re: IBM's 96 column punch card (was System/3)? hancock4@bbs.cpcn.com - 2016-04-22 12:18 -0700

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