1. formula CALculator. An interactive system written by Rick Merrill of DEC in 1969 forPDP-5 and PDP-8. It was a descendant of AID/JOSS. Versions: FOCAL-69, FOCAL-1971, FOCAL-11 (forPDP-11 under RT-11). (1994-12-21) 2. forty-One CAlculator Language. The programming language of the HP-41 calculator line. (1994-12-21)