We connected a dumb terminal to the DIGI-NEO port with flow control disabled on this terminal. -Output with CAT test.txt > ttynnn results in receiving the first 56 characters of the file. - if there would be a problem with flow control I would expect to lose random characters but not receiving only the first 56 characters and losing the rest of the file. We did the same test at both 300 and 9600 baud and have exactly the same result. He same test works perfect on com1: DPA on the port works fine. Replacing the loop-back connector with a dumb-terminal shows 128 A sent. If we enable the terminal in unix, the port behave as a normal terminal without loosing characters. We are running SCO-Unix open server v 5.0.7 on a HP Proliant ML310, Digi neo port Driver V A.0.2a What are we missing ????