Shift:
   MOV         R3,A
Loop:
   CLR         C
   MOV         A,R4
   RRC         A
   MOV         R4,A
   MOV         A,R5
   RRC         A
   MOV         R5,A
   MOV         A,R6
   RRC         A
   MOV         R6,A
   MOV         A,R7
   RRC         A
   MOV         R7,A
   DJNZ        R3,Loop
   RET