A very basic (and slow) raycasting engine, written in FORTRAN 77 for MS-DOS. The program uses BIOS interrupts for input handling and video memory access.
Due to the limitations of the ANSI FORTRAN 77 language standard, the program must be build with the (free) Open Watcom FORTRAN 77 compiler and linked with the DOS/4G 32-bit DOS extender.
Compile and run the executable with:
> wfl386 src\f773d.for /l=dos4g
> f773d.exe
ISC