I was able to get version 9.10 -loop option working. Many thanks to Ken for making this go. Attached is a blurb about RS-232 signals and a diagram of the Y splitter cables I made up to play -LOOP. Hope it's useful. 73, Fred, KE7X

Make up identical Y-adapters with DB9 connectors to plug into each computer. This scheme lets you use the normal Null Modem cables you use for CT operation without the -LOOP option.

DB9 Female                    
At Computer                   

RxD  2  O------------* 2 RxD  DB9 Male
GND  5  O--+---------* 5 GND  "from" network
           |     
           +---------* 5 GND  DB9 Male
TxD  3  O------------* 3 TxD  "to" network
RTS  7  O--+  
           | RTS and CTS shorted
CTS  8  O--+