AST 4 port serial card

[Paul Derks]

I recently bought a cheap AST 4 port serial card CC832, is this
the standard AST 4 port card which is supported by FAS? The
interupt switches are pretty obvious but could someone please tell
me what dipswitch SW3 does, it has four labels:
   XA1
   XA0
   INT
   SHR

Thanks in advance
 
Paul Derks