FOCAL (programming language)

FOCAL is an interpreted programming language that resembles JOSS. Its name is an acronym for Formulating On-Line Calculations in Algebraic Language. The Programming Language Database dates it to 1968 and credits Richard Merrill as its main creator. It was written for the PDP-8 computers made by Digital Equipment Corporation, and that machine family is where it had its largest effect. The sample program shown on the database page is typical of the language: its lines carry numbers in the form 01.10, and it uses commands such as ASK, SET, IF, TYPE and GOTO to read a birth year, compute a value and print a reply. The database lists JOSS, BASIC and MUMPS as related languages, which places FOCAL in the family of early conversational, interactive languages meant to be used at a terminal.