[plt-scheme] BASE64(bytes) CR LF

From: hendrik at topoi.pooq.com (hendrik at topoi.pooq.com)
Date: Tue Sep 25 09:37:31 EDT 2007

On Tue, Sep 25, 2007 at 08:52:28AM -0400, Geoffrey S. Knauth wrote:
> On Sep 25, 2007, at 07:10, hendrik at topoi.pooq.com wrote:
> >What many Linuxers probably don't know is that in this instance,  
> >Windows
> >actually followed the international standard, which dates back at
> >least to the 60's, and Unix was the standards-evading culprit in the
> >70's.
> It makes me smile to think of Unix as standards-evading.  I think the  
> folks behind Unix saw newline as a logical operation that could be  

Certainly, that's why C called it \n instead of something more 

> translated into physical operations (CRLF [1] for Teletypes, cursor  
> addressing for newfangled CRTs) through device drivers, and they  
> foresaw the day when Teletypes and possibly carriage returns would  
> fade into the history books.

Those KSR-33 teletypes had incredibly stiff keys.  Typing was like 
climbing stairs withone's fingers

> We used CRLF 30+ years ago because of Teletypes, which needed a  
> carriage return to physically move the carriage back, and a line feed  
> to advance to the next line.  I knew some Teletype-era renegades who  
> insisted on doing line feeds first and then carriage returns,  
> thinking the sequences were equivalent.  LFCR was not equivalent to  
> CRLF for at least two reasons:  (1)  Teletypes needed a tenth of a  
> second or so of recovery time after the carriage slammed left if the  
> head had been all the way to the right, and the newline gave the head  
> time to recover enough to start the next line in proper position;

And it was possible to type characters while the carriage was slamming 
back.  They would show up somewhere on the line.

> (2)  
> some forms of Teletype ASCII art, e.g., trying to draw Mona Lisa's  
> face [2], required retyping over a line with different characters one  
> or more times, and that was only possible if you did a CR without the  
> LF.  Once you'd issued a LF, the horse was out of the barn.
> [1] CF=carriage return, LF=linefeed aka newline thanks to K&R

The standards committees have subsequently added a real newline 
character to the chharacter set.  It's one of the control codes with the 
high bit set.  Which brings up the question whether C should now 
implement \n as that new character.  I don't think it will happen.

> [2] http://www.threedee.com/jcm/aaa/index.html
>     http://tinyurl.com/332cll  [from computerhistory.org, scroll to  
> the right]

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