Set Extended Processor Exception Handler Vector
(Protected Mode)

Sets the address of the client's protected mode handler for
the specified protected mode exception.

Call With:

   AX     = 0212H
   BL     = exception/fault number (00H-1FH)
   CX:(E)DX= selector:offset of exception handler

Returns:

   if function successful
   Carry flag= clear

   if function unsuccessful
   Carry flag= set
   AX     = error code
           8021H   invalid value (BL not in range 00H-1FH)
           8022H   invalid selector

Notes:

o  DPMI 1.0 clients should use this function in preference
   to Int 31H Fn 0203H.
o  The protected mode exceptions are sent to the protected
   mode handler of the current client.
o  Refer to the rules for descriptor usage in Appendix D.