; LFTSHFT is for adjusting the TWS reading by one nibble to the left. Thus
        ; a value of "01 23" after this routine will be "12 30". This is to match
        ; FILLRAM routine handling the ADC value display. Call with R0 pointing to
        ; "01".

        LFTSHFT:        MOV     A, @R0                  ; 01
                        SWAP    A                       ; 10
                        MOV     @R0, A                  ; Save interim result of 10
                        DEC     R0                      ; Point to the Low byte
                        MOV     A, @R0                  ; 23
                        SWAP    A                       ; 32
                        ANL     A, #0FH                 ; 02
                        INC     R0                      ; Point to high byte again
                        ORL     A, @R0                  ; 12
                        MOV     @R0, A                  ; Save to high byte
                        DEC     R0                      ; Point to low byte
                        MOV     A, @R0                  ; 23
                        SWAP    A                       ; 32
                        ANL     A, #0F0H                ; 30
                        MOV     @R0, A
                        RET                             ; Hi byte = 12; Low Byte = 30