Apple Pascal and FORTRAN ran under a non-DOS operating system based on UCSD P-System, which had its own disk format and included a "virtual machine" that allowed it to run on many different types of hardware.
Apples Pascal og FORTRAN kørte under et ikke-DOS styresystem USCD P-systemet, som havde sit eget diskformat og inkluderede en ”virtuel maskine” der tillod det at køre på mange forskellige former for hardware.