Autocode

Autocode is a family of "simplified coding systems," an early form of programming language .

History of origin

Autocode is a family of programming languages developed for various computers in the 1950s and 1960s at the Universities of Manchester and Cambridge . Autocode is to be understood as a generic term; the different autocodes for different computers are different from e.g. For example, the different versions of each Fortran language are not necessarily related. The first autocode and its compiler were developed by Alick Glennie for the Manchester Mark I in 1952 and is considered by some to be the first compiled programming language. The second car code, the "Mark 1 car code" was developed for the Mark I RA Brooker in 1954.

Brooker also developed a car code for the Ferranti Mercury in collaboration with the University of Manchester in the 1950s . "Mercury Autocode" had a limited number of variables , a - z and a '- z', and in some ways was similar to early versions of the later "Dartmouth BASIC ". It has some of the concepts later ALGOL ( Algo Rithmic L anguage) anticipated, but still without converting a stack and thus even without recursion and dynamically-allocated arrays . In order to cope with the relatively small memory available on the Mercury , large programs were divided into "chapters" that were used by overlay . Some expertise was required to minimize the time-consuming change of control between individual chapters. This concept of overlaying the drum memory through user control was common until virtual memory management became available in later machines . A slightly changed Mercury car code was also implemented for the Ferranti Atlas ( to be distinguished from later Atlas car codes ), the ICT 1300 and the ICT 1900 .

The version for the EDSAC 2 ( E lectronic D elay S torage A utomatic C alculator) was from DF Hartley of the University of Cambridge developed 1,961th The EDSAC-2 auto code was a subsequent development from the Mercury auto code. It was only adapted to the conditions of the computer and was known for its object code optimization and source language diagnostics, which were progressive for the time. Another version was for the Colossus (ATLAS-2 computer prototype) as a temporary emergency measure used Successors "Titan", while a much more advanced language was developed as today CPL ( C ombined P rogramming L anguage) is known . CPL was never completed, but that of Martin Richards developed BCPL ( B asic C ombined P rogramming L anguage) decided affected, which in turn to the programming B and C was further developed. A contemporary, but separate development thread that Atlas Auto code , was developed by the University of Manchester for the Manchester Mark I developed.

literature

• Martin Campbell-Kelly: Programming the Mark 1: Early Programming Activity at the University of Manchester . In: IEEE (Ed.): Annals of the History of Computing . 2, No. 2, 1980, pp. 130-167. doi : 10.1109 / MAHC.1980.10018 .
• Ernesto Garcia Camarero: AUTOCODE a sistema simplificado de codificacion para la computadora MERCURY . Universidad de Buenos Aires, 1961, p. 70. (Spanish)

Web links

• The Autocodes: a User's Perspective (Archive)

Individual evidence

1. ^ Donald E. Knuth, Luis Trabb Pardo: Early development of programming languages . In: Marcel Dekker (Ed.): Encyclopedia of Computer Science and Technology . September 7, pp. 419-493.