MCT U232-P9 is one of a few usb-to-serial adapters which offer +/-5V USB power bus voltage level upconversion to +/-12V standard serial interface voltage. This feature may be extremely important when devices are powered via serial interface DTR and RTS lines. I bought this dongle to use it with Aware Electronics computer interfaced radiation monitor (RM-60 model). Unfortunately MCT only released driver stack for M.S. Vista/XP 32-bit platforms. So once I upgraded to M.S. Vista 64-bit I had to find an alternative solution. Thanks to open source community, I found open source MCT U232-P9 driver distributed as a part of 2.6 standard kernel distro. However driver source code lacked implementation of ioctl function API. Since RM-60 is interfaced via ring counter (RNG line) serial driver must support TIOCGICOUNT or/and TIOCMIWAIT ioctl commands. I added ioctl implementation for these commands to driver source code and currently in the process of merging my changes to the official distro. Below you could find modified source code along with configure.bsh build and deployment script.