I think that "character pacing" stuff needs to be used, remember that all "pro" communications packages have this feature, for instance: I use one of this programs, and it has a dialogue box where I can choose from 5 miliseconds to none as a pacing delay. I´m not an expert at windows, but a DOS box has a strange way of manipulating COM buffers and pacing, it´s not the same as pure DOS like 6.22. Try to insert a delay. I use an 8752 at 57600 bps and 1 milisecond delay. At 9600 no delay is needed. Regards from Argentina.