VT100 and bagbiting

gwyn at BRL-VLD.ARPA gwyn at BRL-VLD.ARPA
Thu Jun 28 23:56:10 AEST 1984


From:      Doug Gwyn (VLD/VMB) <gwyn at BRL-VLD.ARPA>

This attempt to distinguish one end of the RS232 ASCII link as the
TERMINAL and the other as the COMPUTER, then to assign asymmetrical
rules to the two ends, seems artificial when some so-called terminals
are smarter than the so-called computers they communicate with.  The
original use of Teletype terminals did not involve computers at all,
and each unit would control the paper tape reader on the other when
they were communicating like that.

I watched the evolution of XON/XOFF from close up (I used both
Teletype and high-speed peripheral paper tape on a variety of
computers).  It was a perfectly natural evolution to the current
use for more general flow control.

Some degree of flow control is necessary no matter how fast the
internal logic of a terminal is.  Consider:
	- user opens the lid of the Diablo to change its ribbon
	- terminal scrolls smoothly 6 lines/second while short
	  lines are being received at a rate of 1920 chars/second
Many (maybe even most) computer system and terminal vendors have
faced up to this fact by now.

The "VT52 emulating" terminal with fancier editing features than
the VT100 wouldn't be one of those Visual 200s, would it, Ron?
Having done termcap entries for both and tried them both, I choose
the VT100 any day.  Not to say that the VT100 is perfect, but it is
not at all the big loser that people have been saying it is.



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