Private Sub ButtonChecksum_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ButtonChecksum.Click
        Dim sig As Long
        Dim sigstring As String
        iohelper = New PackageIO.PackageIO(File.Open(FileName, FileMode.Open), Endian.Big)
        UpdateLog("Calculating Checksum. . .")
        length = &H4BB0
        iohelper.Seek(&HD010)
        sig = 0
        Dim x As Integer = 0
        While x < length
            sig += iohelper.ReadInt32()
            x += 4
        End While
        While sig > 4294967296
            sig -= 4294967296
        End While
        sigstring = hexhelper.LongToHex(sig)
        While sigstring.Length > 8
            sigstring = Microsoft.VisualBasic.Mid(sigstring, 2)
        End While
        While sigstring.Length < 8
            sigstring = "0" + sigstring
        End While
        UpdateLog("Done!")
        UpdateLog("Checksum: " & sigstring)
        UpdateLog("Writing Checksum. . .")
        iohelper.Seek(53256)
        iohelper.WriteHexString(sigstring)
        UpdateLog("Done!")
        TextBoxSignature.Text = sigstring
        iohelper.Close()
    End Sub