I know this has been covered before, but I'm no closer to finding a solution to my problem. Here is what I have: I have a USB-to-Serial converter on my iMac. It works perfectly in the Mac world. When I'm running the XP VM I am able to bind the port by attaching the USB-toSerial converter. XP then shows the port attached as COM1: . So far so good. When I run Hyperterminal, it 'sees' this port, but there is no data transfer. DTR and RTS are left low, which is probably no data is flowing. I did notice when I first 'attached' to the VM, DTR and RTS flashed several times. This is as far as I've gotten. I saw a post where a fellow wrote a C program to set up a virtual SIO socket, and bind this to the physical port in the Mac world. Unfortunately, the C source code doesn't do me much good. Is there any way I can get working SIO in the VM, either by binding to the USB-to-Serial adapter or using sockets with a virtual SIO port? Thanks in advance...