I let the app run for about 2 minutes, at the standard priority - basically until the system was about ready to take a dive :) Data was coming in to the program and being displayed before I killed it. The count on WaitCommEvent was 15051 - so I guess we would have 7526 calls to WaitCommEvent in < 2 minutes. It probably took the first 30 seconds just to get the app up and running, so that was maybe 90 seconds of actually accessing the serial port. Thanks for looking into this, Dan _______________________________________________ wine-users mailing list wine-users@xxxxxxxxxx http://www.winehq.org/mailman/listinfo/wine-users