TECO (Texteditor)
TECO (originally Tape Editor and Corrector, later text editor and corrector) is a text editor for computers of the DEC. Developed TECO 1962/63 by Daniel L. Murphy for the PDP -1 at MIT. Originally TECO was used to edit tape.
Versions of TECO there for all PDP computer on the VAX under VMS TECO could also be used thanks to the existing PDP -11 emulation. TECO is still part of the products marketed by Hewlett -Packard current OpenVMS version.
Working with TECO is very cryptic as it was tuned out with as few keystrokes to control the editor or to create powerful macros. As the name suggests, a variety of Teco commands are derived from current operations of a time, was still practiced as programming using scissors, tape and punched cards.
TECO is the predecessor of Emacs, which in its early days was a collection of TECO macros, which made it possible to edit visually comprehensible texts, as today, even in Notepad is the default.
TECO is still run on the various simulated PDP computers, which are available for the simulation of historical computer within the project SIMH. There are also workable TECO versions for Microsoft Windows, Linux and Mac OS X.
TECO as a programming language
TECO is a complete programming language with its macro functions. Alan Kotok wrote a LISP interpreter in Teco during his studies. An essential element for the programming function, the Q register, 36 memory (named 0-9 and AZ), which can accommodate both text and numeric values . Includes a Q register text, this text can be further processed, issued, or - if it is a valid TECO command sequence - are also carried out. It is therefore possible in TECO to generate parts of the program during the first run and then perform.
A Trivial Example of a TECO program ( summation of the numbers from 1 to 100) is 0uA0uB100 <% A qBuB $ > qB = $ $. The occurring here $ sign is entered via the escape key; Escape separates commands ( if necessary) and completed text inputs, Double Escape starts the program.
See also the Hello World example in TECO.