RT-11, MACRO-11 Hello World Example

        .MCALL  .REGDEF,.TTYOUT,.EXIT
        .REGDEF

HELLO:  MOV    #MSG,R1
        MOVB   (R1)+,R0
LOOP:  .TTYOUT
        MOVB   (R1)+,R0
        BNE    LOOP
       .EXIT

MSG:   .ASCIZ  /Hello, world!/
       .END    HELLO