Short Code (computer language)
Template:Short description Script error: No such module "about". Script error: No such module "Infobox".Template:Template otherScript error: No such module "Check for unknown parameters". Short Code was one of the first higher-level languages developed for an electronic computer.[1] Unlike machine code, Short Code statements represented mathematic expressions rather than a machine instruction. Also known as automatic programming, the source code was not compiled but executed through an interpreter to simplify the programming process. The execution time was, naturally, much slower.[2]
History
Short Code was proposed by John Mauchly in 1949 and originally known as Brief Code. William Schmitt implemented a version of Brief Code in 1949 for the BINAC computer, though it was never debugged and tested. The following year Schmitt implemented a new version of Brief Code for the UNIVAC I, where it was now known as Short Code (also Short Order Code). A revised version of Short Code was developed in 1952 for the Univac II by A. B. Tonik and J. R. Logan.[3]
While Short Code represented expressions, the representation itself was not direct and required a process of manual conversion. Elements of an expression were represented by two-character codes and then divided into 6-code groups in order to conform to the 12-byte words used by BINAC and Univac computers.[4] For example, the expression
a = (b + c) / b * c
was converted to Short Code by a sequence of substitutions and a final regrouping:
X3 = ( X1 + Y1 ) / X1 * Y1 substitute variables
X3 03 09 X1 07 Y1 02 04 X1 Y1 substitute operators and parentheses.
Note that multiplication is
represented by juxtaposition.
07Y10204X1Y1 group into 12-byte words.
0000X30309X1
Along with basic arithmetic, Short Code allowed for branching and calls to a library of functions. The language was interpreted and ran about 50 times slower than machine code.[5]
See also
References
External links
- Wexelblat, Richard L. (Ed.) (1981). History of Programming Languages, p. 9. New York: Academic Press. Template:ISBN
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- ↑ Sebesta, R. W. Concepts of Programming languages. 2006; M6 14:18 pp. 44. Template:ISBN.
- ↑ Sebesta, R. W. Concepts of Programming languages. 11E; Chapter 2, pp. 39. Template:ISBN.
- ↑ Schmitt, William F. The UNIVAC SHORT CODE. Annals of the History of Computing (1988) 10:pages 7–8.
- ↑ Schmitt, William F. The UNIVAC SHORT CODE. Annals of the History of Computing (1988) 10:page 15.
- ↑ Malik, Masud Ahmad. Evolution of the High Level Programming Languages: A Critical Perspective. ACM SIGPLAN Notices (December 1998) 33(12) page 74.