; Print a message string
;
        .ORIG x4000             ; Start the program at x4000
        LEA     R2, MSG         ; Pt R2 -> start of message string
LOOP1   LDR     R0, R2, #0      ; R0 = next char of string
        BRZ     DONE            ; Loop until end of string
        TRAP    x21             ; Print current char of string
        ADD     R2, R2, #1      ; Pt R2 to next char of string
        BRNZP   LOOP1           ; Continue loop
DONE    TRAP    x25             ; Halt execution
MSG     .FILL   x0048           ; "H"
        .FILL   x0069           ; "i"
        .FILL   x0000           ; end of string
        .END                    ; End of program