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

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"Dan Espen" <despen@verizon.net> wrote:

[IBM mainframe card readers]
> 2540 and a 2501.
> The 2501 never got much use.
> I always felt the 2501 was a favor for the salesman.

The 2540 wasn't just a card reader; it also had a card punch (and, as an 
optional feature, could use the punch side as a second reader). 
Additionally, the 2540 could not be directly attached to the computer's 
channel; it required a separate control unit (2820) - at, of course, 
additional cost.  (Note that a 2820 could support up to three 140x printers 
in addition to the 2540.)  The 2820 occupied about the same floor space as 
the 2540.

The 2501, on the other hand, had the control unit function built into the 
frame. Where the 2540 used wire brushes to read all 80 columns in parallel 
(9-row first), the 2501 read the card with optical sensors, one column at a 
time (cc1 first).  A distinct advantage of the 2501 in a college environment 
was that it wa reasonably fool-resistant, to the point that my PPOE (a Very 
Large State University) put one in the door to the computer room where 
students could read in their own job decks.

One way that IBM kept down the cost of the 2501 was that while the 2540/2820 
read and stored a complete image of the card just read (and the program 
could read it multiple times (*) before requesting that the next card be 
read), the 2501 had the ability to store only a single column at a time: 
when a column was read the 2501 had to be able to send that column (either 
as an EBCDIC character or as a 12-bit binary field) before the next column 
arrived at the optical sense station.

Joe

(*) This allowed the program to read a card as a binary image, then 
programmatically check cc1 for a 7-9 punch (the flag for a binary card) and 
if the card wasn't binary, then read it again as EBCDIC.  The 2501 didn't 
have this capability, so if you didn't know whether a card was binary or 
EBCDIC you had to read it as binary, and if it wasn't binary, 
programmatically translate the binary data into EBCDIC.  I wrote a program 
to do this, and would hesitate to even guess at the amount of time I spent 
trying to optimize the translation logic (this was on a 360/40, in an 
environment that could not exceed 6 KB for the entire program, so no room 
for a TR table) to be able to request the next card before the reader gears 
reached their clutch point.  I was quite happy to see the binary machine (a 
7040) leave a few years later. 

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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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