hello.z80

#include    "ti83plus.inc"
#define     progStart   $9D95
#define     tbuff  $9000
.org        progStart-2
.db         $BB,$6D
    bcall(_ClrLCDFull)
    ld  HL, 0
    ld  (PenCol), HL
    ld  HL, Message
    ld bc, 12
    call tbuffsscroll
    ret
tbuffsscroll:
    ld de, tbuff
    push bc
    push de
    ldir
    pop bc
    pop hl
tbuffsdisploop:
    ld a, (hl)
    inc hl
    cp $FE
    jr z,tbuffreverseon
    cp $FF
    jr z,tbuffreverseoff
tbuffreverseon:
    set textInverse,(IY+textFlags)
    jr tbuffdispprint
tbuffreverseoff:
    res textInverse,(IY+textFlags)
tbuffdispprint:
    bcall(_VPutMap)
    halt
    halt
    halt
    halt
    halt
    djnz tbuffsdisploop
    ret

Message:
.db "Hello ", $FE, "world!"
Message2:
.db "PEEN"