Learn English – How “macro” in computer programming came about


The prefix macro- is normally used for large things like macroeconomics and macroscopic. How did it come to be used to describe text macros in the programming world?

Best Answer

In computing, "macro" was first used with assemblers, which are utilities that perform simple translation of readable mnemonics into machine instructions. Normally a single line in an input to a basic assembler produces a single machine instruction output; the line is commonly referred to as an instruction. Productivity was increased when the use of what were termed macro-instructions were invented. Macro- is of course a standard prefix from the Greek meaning large, and a macroinstruction was a new kind of input line which would generate several machine instructions.

The OED shows a revealing quote from 1959:

The built-in system macro instructions in SCAT presently consist of (1) two macros for generating theā€„standard entry and exit from subroutines, (2) a set of debugging macros.

This shows use of both the full form, macro instruction, and the abbreviated form, macro. (Quote is from Greenwald & Kane, "The Share 709 System: Programming and Modification", Journal of the ACM 6:133. SCAT ("Symbolic Coder And Translator") was an early macro-assembler.)