PUNTO CHE SI MUOVE

program PUNTO;
uses crt, graph;
const a=0; b=639; c=80; dx=1; dt=1000;
var x:real; k:longint; driver,mode:integer;
begin
driver:= detect;
initgraph(driver, mode,'c:\tp\bgi');
x:=a;
putpixel(round(x),c,15);
outtextxy(30,190,'per partire premi un tasto');
repeat until keypressed;
repeat
putpixel(round(x),c,0);
x:=x+dx;
putpixel(round(x),c,15);
for k:= 1 to round (dt) do begin end;
until x>b;
end.