Public Delegate Sub DisplayData(ByVal Buffer As String)
 
    Private Shared Sub Display(ByVal Buffer As String)
        Buffer = Buffer.Replace(vbLf, vbCr)
        Buffer = Buffer.Replace(vbCr & vbCr, vbCr)
        Buffer = Buffer.Replace(vbCr, vbCrLf)
        With DefInstance.txtTerm
            If (Buffer.Length = 1) And (Buffer = Chr(8)) _
                                                    Then
                If (.Text.Length > 0) Then .Text = _
                    .Text.Remove(.Text.Length - 1, 1)
            Else
                .AppendText(Buffer)
            End If
            If .Text.Length > 8196 Then
                .Text = .Text.Remove(0, 4096)
                If Mid(.Text, 1) = vbLf Then _
                        .Text = .Text.Remove(0, 1)
            End If
            .SelectionStart = .Text.Length
        End With
    End Sub
 
Private Shared Sub SerialPort_DataReceived(ByVal sender As Object, ByVal e As _
    System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort.DataReceived
        Dim Buffer As String = SerialPort.ReadExisting()
        DefInstance.txtTerm.BeginInvoke(New _
            DisplayData(AddressOf Display), _
                    New Object() {Buffer})
    End Sub