Re: Control characters

From: Edward Cherlin (
Date: Sat Jul 08 2000 - 01:47:47 EDT

At 11:00 AM -0800 7/6/00, jgo wrote:
> > John Cowan wrote:
> >> On Wed, 2000-07-05, john wrote:
> >>> John Cowan wrote:
> >>> IIRC, the Model 37 Teletype interpreted 0A as a newline function,

Sorry, YDNRC.

> >> Also models 33 and 38, which also interpreted x0D as carriage return.
> > Definitely not true of the model 33; it interpreted 0A as a line-feed,
> > and if it received one not preceded by 0D
> > it would do this.
> > (Hopefully, you are all reading this email with a fixed-width font as
> > God intended.)
>Hmmm, well, of course, my memory could be faulty, but my recollection
>is that x0A was line-feed and x0D was carriage return, and each
>caused behavior accordingly (except that it was not the paper
>carriage that returned, but the type cylinder carriage) on all
>the Teletype models mentioned.
> >>> so ASCII allowed 0A to be interpreted as either LF or NL.
> >> That's non sequitur, but folks are like that.
> > How so? The LF behavior is different from the NL behavior.

Yes, there is no ASCII NL character. On Teletypes and other ASCII devices

0Ah = ^J = LF = next line, straight down
0Dh = ^M = CR = beginning of line, straight left

exactly as the code charts say. You could send


to overstrike


or you could do it the APL way:


Multiple BS followed by LF was used to mean "delete to end of line"
on APL terimnals.^H^H^H^H^H^H^H^J

Edward Cherlin
"A knot!" exclaimed Alice. "Oh, do let me help to undo it."
Alice in Wonderland

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