Hi, There is a chip from FTDI called the FT232BM which is a USB to serial converter which supports many non standard baud rates, including 31250. Its is quite easy to use, i have used it on a number of other projects, but not as a MIDI interface (yet). I think they even hav a new version (the 232R?) which needs no external components, although i dont know if this one is available in a diy friendly package. I think this would be a very simple solution to the problem, although it obviously provides only one MIDI port. Cheers, Fergus.