Is this it, cant really tell if its correct using random data:

code:
$py = 0
While $frmMain.Visible 
	for $x = 0 to 199
		$y=rnd(100)
		$prgCPU.Value = $y
		$y = 50-$y/2
		$picCPU.Line($x-1,$py,$x,$y) ; inverse
		sleep 0.1
		$py = $y
	next
	$nul=Execute($frmMain.DoEvents)
Loop