Option Explicit
Private iPortADDR As Integer
Private lTimerID As Long
Private LineForCheck As Long
Public Event KeyboardChanged(lKey As Integer)
Public Sub Keyboard_StartWatching(PortAdresse As Integer, Optional WatchCycle _
  As Long = 2)
LineForCheck = 0
lTimerID = SetTimer(0&, 0&, WatchCycle, AddressOf TimerCallBack)
ADD_Cb Me, lTimerID
End Sub
Public Sub Keyboard_StopWatching()
KillTimer 0, lTimerID
REM_Cb lTimerID
lTimerID = -1
End Sub
Friend Function CheckKeyboardState()
Dim iValue As Integer
' hier wird deine Zehnertastatur abgefragt, Delay zwischen 2 Abfragen 2 ms
iValue = Inp(iPortADDR)
If iValue <> 0 Then
   ' ich hoffe, dass INP den Wert aller belegten "senkrechten" Leitungen 
   ' liefert!?
   RaiseEvent KeyboardChanged(iValue)
End If
' hier wird der neue Impuls generiert (waagerechte Leitung)
Out iPortADDR, LineForCheck
If LineForCheck = 0 Then
   LineForCheck = 1
Else
   LineForCheck = LineForCheck * 2
End If
If LineForCheck > 8 Then LineForCheck = 0
End FunctionPrivate Sub Class_Initialize()
lTimerID = -1
LineForCheck = 0
End Sub
Private Sub Class_Terminate()
If lTimerID > 0 Then
   KillTimer 0, lTimerID
   lTimerID = -1
End If
End Sub