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From: toma@tekgvs.LABS.TEK.COM (Tom Almy)
Newsgroups: comp.misc
Subject: Re: Punched Cards
Message-ID: <7619@tekgvs.LABS.TEK.COM>
Date: 6 Jun 90 19:51:25 GMT
References: <12546@netcom.UUCP> <220@taumet.COM> <12573@netcom.UUCP> <1208@mplvax.EDU> <2219@l.cc.purdue.edu>
Reply-To: toma@tekgvs.LABS.TEK.COM (Tom Almy)
Organization: Tektronix, Inc., Beaverton,  OR.
Lines: 22

In article <2219@l.cc.purdue.edu> cik@l.cc.purdue.edu (Herman Rubin) writes:
>
>A little background:  punched cards were read initially a row at a time,
>from the bottom (9) row up.  When a card was sent to a computer, it was
>the left side of the 9's row, the right side, etc.
>
>Fortran was designed for the IBM 704, which was a 36-bit machine.  The 
>card-reading hardware for this machine could not read the right 8 columns
>of the card.

The IBM 407 Accounting Machine (essentually a printing adding machine for
punched cards :-) read in the 12 side first. The accumulators were wheel
like devices, that worked like odometers.  If you were adding a field to
an accumulator (as deturmined by a plug board program) the start of the card
(actually when it reached the 0 row) would start the wheel rotating and as 
soon as a hole was reached the wheel would stop. If it made it all the way
to the nine row then a 9 would be added, for instance. You could consider
this to be a digit parallel design where the digit value is encoded by 
pulse length. You could also consider the 407 to be a multiprocessing system!

As far as I know, all the unit record equipment (except for the sorter)
read and punched cards in the same manner.