INT 21 - DJ GO32.EXE 80386+ DOS extender - DOS EXTENSIONS
AH = FFh
AL = function
01h create file
02h open file
03h get file statistics
04h get time of day
05h set time of day
06h stat
07h system

See also: 10FF

21FF - DJ GO32.EXE 80386+ DOS extender - DOS EXTENSIONS