fas1. Frankenstein Cross Assemblers. A reconfigurable assembler package, especially suited for 8-bit processors, consisting of a base assembler module and a yacc parser, for each microprocessor, to handle mnemonics and addressing. Second party parser modules available from many sites. Base assembler and yacc parser modules by Mark Zenier. FTP: ftp.njit.edu/pub/msdos/frankasm/frankasm.zoo. 2. FAS. A general purpose language sponsored by the Finnish government in the 70's and 80's.