Public Sub DrawRaster(Pic As PictureBox, ByVal RasColor As OLE_COLOR, _
                      ByVal bOnOff As Boolean, _
                      Optional ByVal stepwidth = 64)
 
   Dim x As Integer, y As Integer, i As Integer
   If Not bOnOff Then RasColor = Pic.BackColor
 
   For y = 0 To Pic.ScaleWidth Step stepwidth
      For x = 0 To Pic.ScaleHeight Step stepwidth
          Pic.Line (x, 0)-(x, Pic.ScaleHeight), RasColor
          Pic.Line (0, y)-(Pic.ScaleHeight, y), RasColor
   Next x, y
End Sub