Get Processor Exception Handler Vector

Returns the address of the current client's protected mode
exception handler for the specified exception number.  This
function should be avoided by DPMI 1.0 clients (see Notes).

Call With:

   AX     = 0202H
   BL     = exception number (00H-1FH)

Returns:

   if function successful
   Carry flag= clear
   CX:(E)DX= selector:offset of exception handler

   if function unsuccessful
   Carry flag= set
   AX     = error code
           8021H   invalid value (BL not in range 0-1FH)

Notes:

o  The value returned in CX is a valid protected mode
   selector, not a real mode segment address.
o  32-bit clients will be returned a 32-bit offset in the
   EDX register.
o  Clients which run under DPMI 1.0 should use Int 31H
   Functions 0210H and 0211H to obtain the addresses of
   exception handlers.  This function is supported by DPMI
   1.0 hosts solely for compatibility with DPMI 0.9.