Private Declare Function SetScrollPos Lib "user32.dll" (ByVal hwnd As Int32, _
  ByVal nBar As Int32, ByVal nPos As Int32, ByVal bRedraw As Int32) As Int32
Dim anzahl As Long = 0
 
 
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles Timer1.Tick
    anzahl = anzahl + 1 
    SetScrollPos(Me.RichTextBox1.Handle.ToInt32(), 1, anzahl, 5)
    RichTextBox1.Update()
End Sub