[GreenKeys] Heavymetal, tty bulletins, etc.

[Douglas W. Jones]

On Monday, December 23, 2002, at 11:44 AM, Bill Buzbee wrote:

> I'm in the process of digging through my Heavymetal teletype control 
> program
> to fix the ASCII cr/lf problem that Jack ran into.

This may not be trivial unless you simply give the user the option
of asking for conversion of LF to CR/LF.

Part of the problem is that Windows and Unix have different
conventions for line ends embedded in text files.  Windows
text lines end with CR/LF pairs, while Unix text lines end
with just LF.  I think MacOS just uses CR for line end, making
life even more confusing.

If you convert all LFs to CR/LF, you'll convert Windows style
CR/LF pairs to CR/CR/LF (nice for those with sticky Teletype
carriages that take too long to return).

If you convert all CRs that aren't immediately followed by LF
to CR/LF, you'll fix problems with text files that originated
on someone's Mac, but you'll wreck overprinting that's essential
for some ASCII art.  (but if people use BS for overstrikes,
there's no problem.)

Most ASCII art that uses CR for overstrikes originated on
punched cards, where character 1 of each card indicated whether
this card was the start of a new line or something to overstrike
over the line currently under development.

					Doug Jones
					jones@cs.uiowa.edu