On Wed, 19 Jan 2011 12:00:01 -0600, you wrote: Good idea, suggested by Ed also, so I just tried it. Although VTserver now says it opened COM2:, and starts transmitting (the usual slow scrolling line feeds appear, I don't have it hooked up to the PDP-11)... But. There is nothing actually coming out of the COM2: port! For hardware test purposes, in the MSDOS window "COPY/B <somefile> COM2:" *does* work correctly (I can see with a scope the serial data coming out on the COM2 TxD pin). More ideas please? thanks -Charles