include c:\cxpl\codes;
int     CpuReg, Dir, I, J;
char    Str;
string  0;                      \use zero-terminated strings, instead of MSb set
[CpuReg:= GetReg;               \provides access to 8086 CPU registers
\      0123456789012
Str:= "Hello World! ";
Clear;
Dir:= -1;                       \make string initially scroll to the right
I:= 0;                          \index to start of displayed portion of string
repeat  Cursor(0, 0);           \set cursor position to upper-left corner
        for J:= 0 to 12 do
                [ChOut(0, Str(I));  I:= I+1;  if I>12 then I:= 0];
        Sound(0, 2, 1);         \delay about 1/9 second
        I:= I+Dir;              \step starting position of displayed string
        if I<0 then I:=12;      \wraparound
        if I>12 then I:= 0;
        CpuReg:= GetReg;        \get mouse button press information
        CpuReg(0):= 5;  CpuReg(1):= 0;
        SoftInt($33);           \reverse direction if left button was pressed
        if CpuReg(1) then Dir:= -Dir;
until   KeyHit;                 \any keystroke terminates program
]