August 11, 2010
===============

The files in this directory have been used to test the PC port on the C11-GPS,
C11-CGE, and our (unique) C20.  The PC port uses the auxilliary command set, and
requires a checksum.  It accepts RS232 and converts it to the internal TTL
serial communication that connects the motor controllers and the hand
controller.  An advantage of this hardware interface over the serial interface
through the hand controller is that it is independent of the hand control
microcomputer.  It can monitor the communication between the hand control and
the motor control.

However, on our C20 telescopes, this interface is not electronically reliable. 
Any cable connected to the interface generates miscommunication between the HC
and the motor controllers.  This is not the case for the C11-GPS, but because we
have not been able to use this connection effectively with our own hardware, it
is not currently maintained.

The code here is a partially written implementation of the AUX command set for
the PC interface.  It is >>NOT<< ready for use.  The intialization routine
offers an example of how to talk and listen to the controllers through the PC
port.  It has been used successfully on a C11-GPS and may therefore be useful
for others. 

The same functionality is available through  the hand controller's serial port
(the RJ-11 jack on the HC unit).  Use the files in the nexstar/aux directory for
this purpose. The interface through the hand controller is electronically
robust, is debugged and functional, while this driver is not.

Also please see WARNING for a notice about the maintenance of the code in this
section.