31 Dec
2007
31 Dec
'07
11:35 a.m.
At 12:08 PM 12/31/2007, Chuck Guzis wrote:
No--the use is "Rubout"--erase an erroneous character by overpunching
all holes. Deleting characters from punched paper tape is otherwise
very difficult without a pair of scissors.
I was remembering the description of SUB from Jenning's page:
SUB, Substitute, 1/10 (ASCII-1967). Replaces ASCII-1963 generic
separator character S2. A SUB character replaces a character
that is in error, a sort of placeholder, and produced by
machinery, not humans. Presumably if a character error
such as a parity error is detected, the bad character in a
text is replaced with a SUB, so that the receiving system
can at least detect it; for example:
THE QUICK BROWN FO SUB JUMPS OVER THE LAZY GOD
A SUB character replaces the damaged character following the text "FO".
- John
Date: Mon, 31
Dec 2007 09:41:58 -0600
From: John Foust <jfoust at threedee.com>
I beleive
the original intention was that 0x7F would be _ignored_. The
point being you could overpunch any characeter on paper tape to turn it
into 0x7F (all holes), and thus you could effectively delete that
character from the tape
Wasn't it used to indicate that the previous character could
be ignored?