**************************************************
* System Call: F$Icpt
*
* Function: Sets the function to be called when a signal arrives.
*          
*
* Input:  X = Address of intercept routine
*         U = Address of intercept routine data area
*
* Output: None
*
* Error:  CC = C bit set; B = error code
*
FIcpt    ldx   <D.Proc      get current process pointer
         ldd   R$X,u        Get vector for signal trap handler
         IFNE  H6309
         ldw   R$U,u        Get data area ptr for signal trap handler
         stq   P$SigVec,x   Save them in descriptor
         ELSE
         std   P$SigVec,x
         ldd   R$U,u
         std   P$SigDat,x
         ENDC
         clrb               clear errors
         rts                return