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