V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

TECO
       Tape / Text Editor and COrrector (MIT)


The Jargon File (version 4.4.7, 29 Dec 2003):

TECO
 /tee'koh/, n.,v. obs.

    1. [originally an acronym for ?[paper] Tape Editor and COrrector?; later,
    ?Text Editor and COrrector?] n. A text editor developed at MIT and modified
    by just about everybody. With all the dialects included, TECO may have been
    the most prolific editor in use before EMACS, to which it was directly
    ancestral. Noted for its powerful programming-language-like features and
    its unspeakably hairy syntax. It is literally the case that every string
    of characters is a valid TECO program (though probably not a useful one);
    one common game used to be mentally working out what the TECO commands
    corresponding to human names did.

    2. vt. Originally, to edit using the TECO editor in one of its infinite
    variations (see below).

    3. vt.,obs. To edit even when TECO is not the editor being used! This usage
    is rare and now primarily historical.

    As an example of TECO's obscurity, here is a TECO program that takes a list
    of names such as:


    Loser, J. Random
    Quux, The Great
    Dick, Moby

    sorts them alphabetically according to surname, and then puts the surname
    last, removing the comma, to produce the following:


    Moby Dick
    J. Random Loser
    The Great Quux

    The program is


    [1 J^P$L$$
    J <.-Z; .,(S,$ -D .)FX1 @F^B $K :L I $ G1 L>$$

    (where ^B means ?Control-B? (ASCII 0000010) and $ is actually an alt or
    escape (ASCII 0011011) character).

    In fact, this very program was used to produce the second, sorted list from
    the first list. The first hack at it had a bug: GLS (the author) had
    accidentally omitted the @ in front of F^B, which as anyone can see is
    clearly the Wrong Thing. It worked fine the second time. There is no
    space to describe all the features of TECO, but it may be of interest that
    ^P means ?sort? and J<.-Z; ... L> is an idiomatic series of commands for
    ?do once for every line?.

    In mid-1991, TECO is pretty much one with the dust of history, having been
    replaced in the affections of hackerdom by EMACS. Descendants of an early
    (and somewhat lobotomized) version adopted by DEC can still be found
    lurking on VMS and a couple of crufty PDP-11 operating systems, however,
    and ports of the more advanced MIT versions remain the focus of some
    antiquarian interest. See also retrocomputing, write-only language.


The Free On-line Dictionary of Computing (30 December 2018):

TECO

    /tee'koh/ (Originally an acronym for "[paper]
   Tape Editor and COrrector"; later, "Text Editor and
   COrrector"]) A text editor developed at MIT and modified
   by just about everybody.  With all the dialects included, TECO
   may have been the most prolific editor in use before Emacs,
   to which it was directly ancestral.  The first Emacs editor
   was written in TECO.

   It was noted for its powerful programming-language-like
   features and its unspeakably hairy syntax (see write-only
   language).  TECO programs are said to resemble line noise.
   Every string of characters is a valid TECO program (though
   probably not a useful one); one common game used to be predict
   what the TECO commands corresponding to human names did.

   As an example of TECO's obscurity, here is a TECO program that
   takes a list of names such as:

   	Loser, J. Random
   	Quux, The Great
   	Dick, Moby

   sorts them alphabetically according to surname, and then puts
   the surname last, removing the comma, to produce the
   following:

   	Moby Dick
   	J. Random Loser
   	The Great Quux

   The program is

   	[1 J^P$L$$
   	J <.-Z; .,(S,$ -D .)FX1 @F^B $K :L I $ G1 L>$$

   (where ^B means "Control-B" (ASCII 0000010) and $ is actually
   an alt or escape (ASCII 0011011) character).

   In fact, this very program was used to produce the second,
   sorted list from the first list.  The first hack at it had a
   bug: GLS (the author) had accidentally omitted the "@" in
   front of "F^B", which as anyone can see is clearly the Wrong
   Thing.  It worked fine the second time.  There is no space to
   describe all the features of TECO, but "^P" means "sort" and
   "J<.-Z; ... L>" is an idiomatic series of commands for "do
   once for every line".

   By 1991, Emacs had replaced TECO in hacker's affections but
   descendants of an early (and somewhat lobotomised) version
   adopted by DEC can still be found lurking on VMS and a
   couple of crufty PDP-11 operating systems, and ports of
   the more advanced MIT versions remain the focus of some
   antiquarian interest.

   See also retrocomputing.

   (ftp://usc.edu/) for VAX/VMS, Unix, MS-DOS,
   Macintosh, Amiga.

   [Authro?  Home page?]

   (2001-03-26)