ldsrc:  LDA  src
stdest: STA  dest
        BRZ  done  ; 0-terminated

        LDA  ldsrc
        ADD  one
        STA  ldsrc

        LDA  stdest
        ADD  one
        STA  stdest

        JMP  ldsrc

done:   STP

one:         1

src:         82    ; ASCII
             111
             115
             101
             116
             116
             97
             0

dest: