Int 21 Fn 4B18  U - Fboot V2.13 - Perform Fast Bootstrap                   [-]

   AX = 4B18h
   DX = 0010h
   BX = disk selector
       0000h boot from floppy
       0080h boot from hard disk

Return: never if FastBoot installed
Program: CyberWare FastBoot allows fast warm boots by skipping CMOS
     checking, ROM scan, RAM & peripheral components test

Note:  the only installation check is a search for a character device
     driver called FBOOT$$$