Int 2F Fn FF00 - Topware Network Operating System - Installation Check [N] AX = FF00h Return: AL = 00h not installed, OK to install = 01h not installed, not OK to install = FFh installed See Also: AX=FF01h,AX=FF02h,AX=FF10h,INT 21/AX=FF02h,INT 7A"Topware"