.title bicb ; ; ; Authors: E.F.Beadel, Jr., Manager ; C.A.U.S.E. Instructional Computer Center ; SUNY at Oswego ; Oswego, NY 13126 ; phone: 315/341-3055 ; ; and ; ; T.J.Weslowski, Instructor ; Computer Science Department ; SUNY at Oswego ; Oswego, NY 13126 ; ; Date: 10-aug-83 ; ;************************************************************ ; ; Callable from FORTRAN to perform a BICB instruction. ; ; called by the call ; ; = BICB ( ,) ; ; where = integer or byte variable containing ; value between 0 .. 377 octal ; = integer or byte variable containing ; value to be masked. ; ;************************************************************ ; .mcall .exit bicb:: cmpb (5),#2 ;make sure we have 2 args bne abort tst(5)+ ;skip up to address pointers movb @(5)+,r1 ;fetch mask movb @(5)+,r0 ;and data bic #177400,r0 ;mask out upper byte bic r1,r0 ;and do bic that user wants rts pc ;return to FORTRAN abort: .exit .end