I used the C200H ASCII module connected to an external modem. This module comes with the commands necessary to make inquires to the CPU status, I/O states and memory values. As I remember, the only troube was figuring out the parity number to truncate the control word. But they provided a BASIC algorhythm to do this. I used BASIC to decifer the code words to produce site status. There was some trouble with BASIC getting stuck when reading the com port but found that sturcting the program to transmit and receive a responce in one routine prevented this problem pretty well. The MODEM is set up to automatically go on-hook when carrier is lost. I also had some luck using the BASIC module to provide password protection and dial-out for
problems that needed attention.
