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From: bzs@bu-cs.BU.EDU (Barry Shein)
Newsgroups: comp.emacs
Subject: Re: Half Duplex Editor
Message-ID: <9763@bu-cs.BU.EDU>
Date: Fri, 17-Jul-87 22:50:44 EDT
Article-I.D.: bu-cs.9763
Posted: Fri Jul 17 22:50:44 1987
Date-Received: Sat, 18-Jul-87 17:59:33 EDT
References: <1026@water.UUCP> <8707091403.AA21054@ucbvax.Berkeley.EDU> <2882@ncoast.UUCP>
Followup-To: comp.emacs
Distribution: world
Organization: Boston U. Comp. Sci.
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In-reply-to: allbery@ncoast.UUCP's message of 14 Jul 87 01:36:20 GMT

Posting-Front-End: GNU Emacs 18.41.4 of Mon Mar 23 1987 on bu-cs (berkeley-unix)



Several years ago, before XEDIT, a student here at BU wrote an
interesting full screen editor that worked reasonably well on H19 or
equivalent terminals on an IBM half-duplex (3705) line. Basically it
buffered up the keystrokes which were being edited and performed
locally and just kept the edit buffers in sync. It had an escape for
extended commands. It used the local edit ability of the terminal and,
when enter is hit and the whole mess goes down to the machine, run
down the list to figure out how things have changed. The only main
problem was that there was a limit of 255 chars per "record" after
which the IBM multiplexor would just truncate the line. It used an
interesting terminal mode that was in there to support paper tapes
transmission from ttys, I think this was to ensure that the line was
flow controlled. I made some progress writing a similar editor for
use within Lisp on the same system (written in lisp of course.)

As I always say, animals caught in a trap will gnaw their legs off
to escape :-)

	-Barry Shein, Boston University