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

From jmfbahciv <See.above@aol.com>
Newsgroups alt.folklore.computers
Subject Re: IBM's 96 column punch card (was System/3)?
Date 2016-04-27 12:40 +0000
Organization "Have EDDT, will travel"
Message-ID <PM00053176BCF5B066@aca4129f.ipt.aol.com> (permalink)
References <PM00053161ACFBFD0A@aca405eb.ipt.aol.com> <PM00053161ACFBFD0A@aca405eb.ipt.aol.com> <PM00053161ACFBFD0A@aca405eb.ipt.aol.com> <I4udnfRhIayzXoLKnZ2dnUU7-UXNnZ2d@giganews.com>

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Jon Elson wrote:
> jmfbahciv wrote:
>
>
>> The guy who wrote the software for the TU78 had to resort to using
>> iron filing fluid debug the hard/software for a while.  I hated that
>> controller.
> You could view an 800 BPI tape very easily with magna-see, and even read the
> data out.
>
> 1600 BPI was a lot harder to see, as the data was encoded in the location of
> the flux changes, and there was a flux change every bit time in the track.
>
> 6250 BPI would be impossible to actually read anything.  You could verify
> the size of the data blocks and the gaps, but not much else.  Most GCR
> formatters did not allow you to see much of what was in the raw data,
> either, so they either read the data with some errors, or they gave you
> nothing at all.  So, if the format was more than a little off, it could be
> quite hard to tell what was wrong.  I suppose you could hook a logic
> analyzer to the read amps and then you'd be able to pick it apart.
>
>
> Our first 780 had a TU77, and it had a LOT of problems, mostly related to
> heat buildup almost melting the tape.  There were several phases of mod kits
> put on, the last one was a huge radiator for the bearing air and a row of
> boxer fans to cool it.  I always WISHED we had a TU78 as the backups took 13
> tapes per drive at 1600.

DEC never managed to manufacture a good tape drive.  My favorite was the
TU70s followed by TU40s.  Everything else hung a PDP-10 was crap.  I always
wondered why we couldn't make a good tape drive since we did make the
best tape mechanism called DECtapes (the real DECtapes, not those others
they called DECtapes to make them look good).

>
> Our 2nd 780 had Storage Tek 6250 drives.  They were very reliable, but the
> formatter was bigger than a PDP-11/44.

If you wanted reliable magtapes, it required lots of good, working gear.

/BAH

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Re: IBM's 96 column punch card (was System/3)? jmfbahciv <See.above@aol.com> - 2016-04-26 11:42 +0000
  Re: IBM's 96 column punch card (was System/3)? Jon Elson <jmelson@wustl.edu> - 2016-04-26 14:36 -0500
    Re: IBM's 96 column punch card (was System/3)? Morten Reistad <first@last.name.invalid> - 2016-04-27 00:42 +0200
      Re: IBM's 96 column punch card (was System/3)? scott@slp53.sl.home (Scott Lurndal) - 2016-04-27 13:48 +0000
        Re: IBM's 96 column punch card (was System/3)? Morten Reistad <first@last.name.invalid> - 2016-04-28 08:41 +0200
    Re: IBM's 96 column punch card (was System/3)? jmfbahciv <See.above@aol.com> - 2016-04-27 12:40 +0000
      Re: IBM's 96 column punch card (was System/3)? Andy Burns <feb2017-usenet@adslpipe.co.uk> - 2016-04-27 14:51 +0100
        Re: IBM's 96 column punch card (was System/3)? Jon Elson <elson@pico-systems.com> - 2016-04-27 22:27 -0500
          Re: IBM's 96 column punch card (was System/3)? jmfbahciv <See.above@aol.com> - 2016-04-28 12:06 +0000
            Re: IBM's 96 column punch card (was System/3)? Quadibloc <jsavard@ecn.ab.ca> - 2016-04-28 07:49 -0700
              Re: IBM's 96 column punch card (was System/3)? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2016-04-28 17:03 +0000
                Re: IBM's 96 column punch card (was System/3)? "Osmium" <r124c4u102@comcast.net> - 2016-04-28 12:18 -0500
                Re: IBM's 96 column punch card (was System/3)? Anne & Lynn Wheeler <lynn@garlic.com> - 2016-04-28 11:19 -0700
                Re: IBM's 96 column punch card (was System/3)? hancock4@bbs.cpcn.com - 2016-04-28 14:19 -0700
                Re: IBM's 96 column punch card (was System/3)? "Charles Richmond" <numerist@aquaporin4.com> - 2016-04-29 16:47 -0500
              Re: IBM's 96 column punch card (was System/3)? jmfbahciv <See.above@aol.com> - 2016-04-29 12:18 +0000
            Re: IBM's 96 column punch card (was System/3)? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2016-04-28 17:03 +0000
              Re: IBM's 96 column punch card (was System/3)? jmfbahciv <See.above@aol.com> - 2016-04-29 12:18 +0000
                Re: IBM's 96 column punch card (was System/3)? Morten Reistad <first@last.name.invalid> - 2016-04-29 15:14 +0200
            Re: IBM's 96 column punch card (was System/3)? pechter@pechter.net (William Pechter) - 2016-05-03 14:09 +0000
      Re: IBM's 96 column punch card (was System/3)? Jon Elson <elson@pico-systems.com> - 2016-04-27 22:19 -0500
        Re: IBM's 96 column punch card (was System/3)? pechter@pechter.net (William Pechter) - 2016-05-03 14:21 +0000
      Re: IBM's 96 column punch card (was System/3)? pechter@pechter.net (William Pechter) - 2016-05-03 14:03 +0000
        Re: IBM's 96 column punch card (was System/3)? Jon Elson <jmelson@wustl.edu> - 2016-05-03 13:58 -0500
        Re: IBM's 96 column punch card (was System/3)? Jon Elson <jmelson@wustl.edu> - 2016-05-03 14:22 -0500
          Re: IBM's 96 column punch card (was System/3)? pechter@pechter.net (William Pechter) - 2016-05-04 20:21 +0000
        tape drives [was Re: IBM's 96 column punch card (was System/3)?] Rich Alderson <news@alderson.users.panix.com> - 2016-05-03 15:39 -0400
        Re: IBM's 96 column punch card (was System/3)? jmfbahciv <See.above@aol.com> - 2016-05-04 13:02 +0000
          Re: IBM's 96 column punch card (was System/3)? Jon Elson <elson@pico-systems.com> - 2016-05-04 11:45 -0500
            Re: IBM's 96 column punch card (was System/3)? Morten Reistad <first@last.name.invalid> - 2016-05-05 01:13 +0200
              Re: IBM's 96 column punch card (was System/3)? Jon Elson <jmelson@wustl.edu> - 2016-05-05 14:25 -0500
                Re: IBM's 96 column punch card (was System/3)? scott@slp53.sl.home (Scott Lurndal) - 2016-05-05 19:34 +0000
                Re: IBM's 96 column punch card (was System/3)? jmfbahciv <See.above@aol.com> - 2016-05-06 13:28 +0000
                Re: IBM's 96 column punch card (was System/3)? scott@slp53.sl.home (Scott Lurndal) - 2016-05-06 14:39 +0000
                Re: IBM's 96 column punch card (was System/3)? scott@slp53.sl.home (Scott Lurndal) - 2016-05-06 14:41 +0000
                Re: IBM's 96 column punch card (was System/3)? jmfbahciv <See.above@aol.com> - 2016-05-07 13:14 +0000
                Re: IBM's 96 column punch card (was System/3)? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2016-05-07 16:47 +0000
                Re: IBM's 96 column punch card (was System/3)? Andrew Swallow <am.swallow@btopenworld.com> - 2016-05-07 23:30 +0100
                Re: IBM's 96 column punch card (was System/3)? jmfbahciv <See.above@aol.com> - 2016-05-08 13:08 +0000
                Re: IBM's 96 column punch card (was System/3)? Jon Elson <elson@pico-systems.com> - 2016-05-07 16:07 -0500
                Re: IBM's 96 column punch card (was System/3)? scott@slp53.sl.home (Scott Lurndal) - 2016-05-07 21:23 +0000
                Re: IBM's 96 column punch card (was System/3)? jmfbahciv <See.above@aol.com> - 2016-05-08 13:08 +0000
                Re: IBM's 96 column punch card (was System/3)? scott@slp53.sl.home (Scott Lurndal) - 2016-05-09 15:13 +0000
                Re: IBM's 96 column punch card (was System/3)? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2016-05-09 17:05 +0000
                Re: IBM's 96 column punch card (was System/3)? pechter@pechter.net (William Pechter) - 2016-05-09 22:41 +0000
                Re: IBM's 96 column punch card (was System/3)? Morten Reistad <first@last.name.invalid> - 2016-05-10 12:01 +0200
                Re: IBM's 96 column punch card (was System/3)? Peter Flass <peter_flass@yahoo.com> - 2016-05-10 06:42 -0400
                Re: IBM's 96 column punch card (was System/3)? jmfbahciv <See.above@aol.com> - 2016-05-10 12:34 +0000
                Re: IBM's 96 column punch card (was System/3)? scott@slp53.sl.home (Scott Lurndal) - 2016-05-10 13:05 +0000
                Re: IBM's 96 column punch card (was System/3)? jmfbahciv <See.above@aol.com> - 2016-05-11 12:18 +0000
                Re: IBM's 96 column punch card (was System/3)? scott@slp53.sl.home (Scott Lurndal) - 2016-05-11 13:27 +0000
                Re: IBM's 96 column punch card (was System/3)? Morten Reistad <first@last.name.invalid> - 2016-05-10 15:53 +0200
                Re: IBM's 96 column punch card (was System/3)? jmfbahciv <See.above@aol.com> - 2016-05-11 12:18 +0000
                Re: IBM's 96 column punch card (was System/3)? "Simo" <dhy287@gmail.com> - 2016-05-10 04:56 +1000

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