Display-less computing was Re: TOP POSTING
Fred Cisin
cisin at xenosoft.com
Sun Dec 13 13:20:52 CST 2015
> > So did you have to learn how to read the punch hole cards also or did
> > the punch hole cards go into the computer and than printed out the
> > data on the fan fold paper also was it in code or just plane English?
> You COULD read the holes, if you really HAD to. Keypunches printed
> the alphanumeric form on the top edge of the cards. if you punched a
> deck of cards on the CPU's card punch, there was no printing. If it
> was an "object deck" ie. binary code, you would never "interpret" the
> deck. But, if it had something that might be human readable, there
> was a machine called an interpreter, and it would type the symbols on
> the top of the card for you.
At
https://en.wikipedia.org/wiki/Punched_card#/media/File:Blue-punch-card-front-horiz.png
is a picture of a card. It was punched with a printing punch, or run
through a 029 series interpreter punch, NOT with an INTERPRETER, which
didn't line up what it printed with the columns (too large a font to do
so), and couldn't interpret and run COBOL anyway.
Notice the punches used for the numbers.
The rows above '0' were called 'Y' and 'X'
Now look at the punches used for 'A' and 'B', and the relationship
between them.
Now look at 'K', and compare it with 'J', 'L', and 'B'
Now look at 'T', and compare it with 'S', 'U', 'B', and 'K'
Letters and numbers were a simple easy to learn pattern. I never fully
learned the patterns for punctuation characters, and had to often look
them up.
The diagonally cut corner was not always on the left (incompletely
standardized)
There was another special purpose punch, called a "VERIFIER".
You loaded it up with cards that were already punched, and proceeded to
type from the same coding sheet. If the whole card matched, then it put a
little notch in the 80 end of the card, to show that its content was
confirmed, or "VERIFIED". If the content didn't match, then the VERIFIER
put a notch in the top edge of the card above the column that didn't
match.
Sometimes service bureaus that were hired to keypunch would verify whole
boxes of blank cards. Then they could give their client decks of
"VERIFIED" cards, without having to actually rekey the content. Yes, we
did run into them.
Hanging Chad was a miscarriage of justice.
Bury me face down, 9 edge first.
--
Grumpy Ol' Fred cisin at xenosoft.com
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