Re: Castle Adventure by David Malmberg

[mjmahon@aol.com (Michael J. Mahon)]

Paul Schlyter wrote:

<snip>

>Windows inherited the 0D0A end-of-line sequence from MS-DOS, which
>inherited it from CP/M-80, which inherited it from TOPS-20.

<snip>

>The reason for these different conventions of representing an
>end-of-line is that the ASCII character set lacks a representation
>for "end-of-line".  The closest it gets are the ASCII control
>characters "Carriage Return" (0D) and "Line Feed" (0A).  And to
>start a new line on a printer which is controlled by the ASCII
>control characters, you must send to the printer a 0D followed
>by a 0A (or the other way around).  If you just send 0D's to the
>printer, all lines will overwrite one another, and if you just
>send 0A's then the next line will start immediately below the END
>of the previous line.

Ah, the joys of teletypes!  ;-)

The reason that CR-LF order was preferred is that CR took some
teletypes more than a single character time to be performed,
while LF always finished in a single character time.  So CR-LF
gave the CR another character time to finish before any printing
characters arrived, preventing a "flying" character at the beginning
of the next line.

Timing considerations like these were one of the uses of the
NUL character, but it could be avoided in most cases.

-michael

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