🚀 go-pugleaf

>From EAK@MIT-MC  Fri Oct  2 17:18:56 1981
Date: 1 Oct 1981 23:09:17-PDT
From: CSVAX.MAILER-DAEMON at Berkeley
To:   EAK
Re:   Unable to deliver mail

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pots-editor-people... User unknown

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>From EAK@MIT-MC Thu Oct  1 23:00:36 1981
Mail-from: ARPANET site MIT-MC rcvd at 1-Oct-81 2237-PDT
Date: 2 October 1981 01:33-EDT
From: Earl A. Killian <EAK at MIT-MC>
Subject:  function keys
To: editor-people at SU-SCORE

I thought I'd point out a technique that Robert Wells at BBN used
in his editor's command set.  He wisely decided that everything
should be doable via terminal indepedent control characters, but
that function keys should work too when they're available (in a
terminal dependent manner).

This would be easy if either 1) all function keys were
programmable (in particular the arrow keys), or 2) it was always
possible to distinquish a function key from something the user
types (e.g. function keys send ^\ X and the ^\ key sends ^\ ^\).

Unfortunately neither of these is true for commercial terminals.
However, most (but not all!) terminals prefix their function key
sequences with ESC, so he did the next best thing: he did not
used the ESC key in the terminal independent command set.  Thus
ESC A can be made to move up on a VT100, and something else on a
C100.  The user that wants to edit in a terminal independent
manner doesn't care because ESC is not used in any of the
commands he uses.

Such are the hacks that are necessary to live in the commercial
world.