#define b_call(label) rst 28h \ .dw label 

.nolist
#include "ti83plus.inc"
.list

.org  $9D93
.db $BB, $6D

    b_call(_ClrLCDFull)
    ld    hl, 0
    ld    (curRow), hl
    ld    hl, msg
    b_call(_PutS)            ; Display the text
    b_call(_NewLine)
    ret

msg:
    .db "Hello world!", 0
.end
.end