First appeared 1950 (1950) | ||
Developer William F Schmidt, A.B. Tonik, J.R. Logan | ||
Short Code was one of the first higher-level languages ever developed for an electronic computer. Unlike machine code, Short Code statements represented mathematic expressions rather than a machine instruction. Also known as an automatic programming, the source code was not compiled but executed through an interpreter to simplify the programming process; the execution time was much slower though.
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.
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. For example, the expression:
a = (b+c)/b*cwas 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 multiplication is represented by juxtaposition. 07Y10204X1Y1 group into 12-byte words. 0000X30309X1Along 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.