| Developer | William F Schmitt, A. B. Tonik, J. R. Logan |
|---|---|
| First appeared | 1950 |
| Influenced by | |
| ENIAC Short Code | |
| Influenced | |
| Intermediate programming language, OMNIBAC Symbolic Assembler | |
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]
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*cwas converted to Short Code by a sequence of substitutions and a final regrouping:
X3=(X1+Y1)/X1*Y1substitutevariablesX30309X107Y10204X1Y1substituteoperatorsandparentheses.Notethatmultiplicationisrepresentedbyjuxtaposition. 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]