Int 2F Fn B901  - PC Network Receiver.com - Get Receiver.com Int 2f Handl  [N]

   AX = B901h

Return: AL = ???
   ES:BX -> RECEIVER.COM INT 2F handler
Desc:  allows more efficient execution by letting the caller bypass any other
     INT 2F handlers which have been added since RECEIVER.COM was
     installed