Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!ncar!ico!ism780c!news
From: news@ism780c.isc.com (News system)
Newsgroups: comp.misc
Subject: Re: Punched Cards
Message-ID: <43611@ism780c.isc.com>
Date: 7 Jun 90 20:51:12 GMT
References: <12546@netcom.UUCP> <220@taumet.COM> <12573@netcom.UUCP> <898@nlsun1.oracle.nl> <1990May29.132631.2253@pdn.paradyne.com> <1990May30.065025.25861@diku.dk> <1990Jun1.211352.4749@unhtel.uucp> <5157@stpstn.UUCP> <54@apex.UUCP>
Reply-To: marv@ism780.UUCP (Marvin Rubenstein)
Distribution: comp
Organization: Interactive Systems Corp., Santa Monica CA
Lines: 22

In article <54@apex.UUCP> chuckh@apex.com (Chuck Huffington) writes:
>Y                       In the old IBM 709, which was the vacuum tube (valve)
>version of the 7090 the system card reader read only columns 1-72.

The 7090 was a transistor version of the 709 :-)  The machines did not have
the same architecture.  The 709 had 3 index registers.  The 7090 had 7.
Also the 7090 had double precision floating point instructions.   It is
interesting that the 7090, IBM's first transister computer, was announced
just after Philco announced its transistor machine, the Philco 2000.

>
>As I recall a lot of cards also came in thru an off line card to tape
>machine.  They read the whole card and wrote it in BCD on 7 track tapes.

Nope, the cards were read in binary (allowing all 12 punches in a column)
and written in binary.  Tapes had two modes, binary and BCD.  In binary mode
a tape frame could represent all 64 combinations of the 6 bit frame (the
7'th bit was parity).  In BCD mode only 63 combinations were allowed.
Binary mode used odd parity.  BCD mode used even parity.  In order to detect
a parity error in BCD, the data patern of all zero bits was not allowed.

 Marv Rubinstein  -- Don't ask how I remember all this trivia, I don't know