I have posted the source to "Internal Serial Enabler" - a small newton app that allows you to view and control a few of the signals of the internal serial slot on the MessagePad 2x00:
- gpSerPortSel - the serial port 0 selection signal. When high, the internal serial driver is disabled, leaving Serial0 available for the internal slot.
- PortSelect - the serial port 3. When high, Serial3 is available for the internal slot. When low, Serial3 is dedicated for the external interconnect port.
- General Purpose I/O - Pin 26 can either be an input or output signal. Using the app, you can select whether you want the app to be an input or an output. If you select 'output', you can control the signal.