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Re: Byte

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Fred Weigel <fridtjof.martin.weigel@gmail.com> writes:
> 12 bits b/c a card has 12 punch rows

pre-360, bcd was alphanumerica, small subset of 12 punch row
combination.

compatibility with pre-360 cards was "column binary" ... two six-bit
"bytes" per column. read/write on 360 ... would (column binary) i/o card
with 160 length ... two 360 bytes per column (using just 6bits/byte).

univ. had 709 tape->tape with 1401 "unit record" front-end running MPIO
(tape->printer/punch, card read->tape). They were sold a 360/67 for
TSS/360, replacing 709/1401. Temporarily pending arrival of 360/67, the
1401 was replaced with 360/30 (which had 1401 emulation mode).  I had
just taken two credit hr intro to fortran/computers and at the end of
the semester I was hired to rewrite 1401 MPIO in 360 assembler (running
360/30 as 360 instead of as 1401). The univ. shutdown the datacenter on
weekends and they gave me bunch of software & hardware manuals and I
would have the datacenter all to myself over the weekends (although
48hrs w/o sleep made monday classes hard). I got to design & implement
my own monitor, device drivers, interrupt handlers, error recovery,
storage management, etc. Within a few weeks had 2000 card 360 assembler
program.

Later, I assumed it was just exercise in somebody learning 360 (since
1401 MPIO ran just fine on 360/30 in 1401 emulation). Within year of
taking intro class, 360/67 came in (replacing 709 & 360/30), TSS/360
never came into production, and I was hired fulltime responsible for
OS/360 (and continued to have my dedicated weekend 48hr datacenter
time).

2540 reader/punch
https://en.wikipedia.org/wiki/IBM_2540

2540 trivia: univ. class registration was card based. 2540 had five
output stackers, two dedicated for reader, two dedicated for punch and
middle stacker could feed from both reader and punch. program processing
cards would read into middle stacker. punch feed was was loaded with
colored striped cards ... if a problem was found with registration card,
a blank card would be "punched" into middle stacker behind problem
card. There was more than a dozen card trays (2000+ cards/tray). After run
would pull each registration card that had a blank colored card behind
it (for further processing).


-- 
virtualization experience starting Jan1968, online at home since Mar1970

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Byte Peter Flass <peter_flass@yahoo.com> - 2022-11-10 07:06 -0700
  Re: Byte Peter Flass <peter_flass@yahoo.com> - 2022-11-10 07:29 -0700
    Re: Byte scott@slp53.sl.home (Scott Lurndal) - 2022-11-10 15:00 +0000
  Re: Byte Dan Espen <dan1espen@gmail.com> - 2022-11-10 10:40 -0500
  Re: Byte Timothy McCaffrey <timcaffrey420@gmail.com> - 2022-11-10 11:20 -0800
    Re: Byte Peter Flass <peter_flass@yahoo.com> - 2022-11-11 10:11 -0700
      Re: Byte Mike <mlevinespmfltr@redshift.com> - 2022-11-11 12:32 -0800
      Re: Byte Fred Weigel <fridtjof.martin.weigel@gmail.com> - 2022-11-12 07:51 -0800
        Re: Byte Anne & Lynn Wheeler <lynn@garlic.com> - 2022-11-14 09:01 -1000
    Re: Byte Louis Krupp <lkrupp@invalid.pssw.com.invalid> - 2022-11-18 13:02 -0700
  Re: Byte Vir Campestris <vir.campestris@invalid.invalid> - 2022-11-11 21:33 +0000
    Re: Byte John Levine <johnl@taugh.com> - 2022-11-15 18:43 +0000
  Re: Byte Quadibloc <jsavard@ecn.ab.ca> - 2022-11-17 22:26 -0800

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