Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!yetti!geac!daveb
From: daveb@geac.UUCP (Dave Brown)
Newsgroups: comp.emacs
Subject: Re: Half Duplex Editor
Message-ID: <942@geac.UUCP>
Date: Sun, 19-Jul-87 11:10:29 EDT
Article-I.D.: geac.942
Posted: Sun Jul 19 11:10:29 1987
Date-Received: Sun, 19-Jul-87 18:35:42 EDT
References: <1026@water.UUCP> <8707091403.AA21054@ucbvax.Berkeley.EDU> <2882@ncoast.UUCP> <9763@bu-cs.BU.EDU>
Reply-To: daveb@geac.UUCP (Dave Brown)
Distribution: world
Organization: The little blue rock next to that twinkly star.
Lines: 27
Summary: algorithm

In article <9763@bu-cs.BU.EDU> bzs@bu-cs.BU.EDU (Barry Shein) writes:
>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. 

  I once wrote one in competition with my boss at Honeywell, and
I'd like to pass on his version of the algorithm for dealing
with the "buffer overfull" problem:
  read a line from the input
  if it ends in \n, it was properly terminated
    process all the keystrokes
  if it doesn't end in \n, it got truncated
    process all the keystrokes
    redraw from the last cursor position
    ring the terminal bell

  This caught about 99% of the errors, and always warned the user.

  That isn't to say I *recommend* half-duplex editors, though.

-- 
 David (Collier-) Brown.              |  Computer Science
 Geac Computers International Inc.,   |  loses its memory
 350 Steelcase Road,Markham, Ontario, |  (if not its mind)
 CANADA, L3R 1B3 (416) 475-0525 x3279 |  every 6 months.