Int 21 Fn 2B  - Wdtsr.com - Installation Check                             [G]

   AH = 2Bh
   CX = 6269h ('bi')
   DX = 742Dh ('t-')

Return: AL = FFh if not installed
   AL = 77h ('w') if WDTSR is installed
       CX = 6174h ('at')
       DX = 6368h ('ch')
       ES = resident code segment
       ES:DI -> identification and configuration data
Program: WDTSR is a driver for the bitWatch watchdog hardware by bit-design
     GmbH

See Also: AH=2Bh/CX=6269h"bitFOSSI",INT 14/AH=14h"FOSSIL",INT 15/AH=C3h