{------------RQuer IESP 3/12/96-----------}
program volt3;     {Voltmetre … "colonne"}
uses graph,{orphy,}crt;
var i,y,n,gr:integer;
    u:real;
    caract:char;
    ch:string;
{-----------------------------------------}
function ea(n:integer):integer;
begin ea:=random(256);end;
  {remplace la saisie d'une tension par l'interface (orphy...)}
{-----------------------------------------}
begin
randomize;
  gr:=0;
  initgraph(gr,gr,'c:\tp\bgi');
  setbkcolor(white);
  setcolor(blue);
  rectangle(270,15,365,33);
  outtextXY(282,20,'Voltmetre');
  rectangle(300,100,340,252);{250+2 pour le cas o— u=0}
  for i:=0 to 5 do
     begin
     line(299,250-30*i,280,250-30*i);
     str(i,ch);
     outtextXY(250,245-30*i,ch);
     end;
  caract:='z';
  repeat
     n:=ea(0);
     u:=n*5/255;
     y:=trunc(250-30*u+1);
     setcolor(blue);
     line(301,y,339,y);
     setfillstyle(1,red);
     floodfill(320,y+1,blue);
     delay(500);
     setfillstyle(1,white);
     floodfill(320,y+1,blue);
     setcolor(white);
     line(301,y,339,y);
     if keypressed then caract:=readkey;
  until ord(caract)=27;
end.

Le programme executable Volt3.exe

Le programme source