MAIN    START
        PUSH    0,GR1
        PUSH    0,GR2
        LAD     GR1,OBUF
        LAD     GR2,LEN
        SVC     2
        LAD     GR1,=#A
        LAD     GR2,=1
        SVC     2
        POP     GR2
        POP     GR1
        RET
OBUF    DC      'abc'
LEN     DC      3
        END