Tom, Your information was incredibly useful, and the MAX3100 seems extrodinary, but I was really interested in driving 2 or even three (if I'm greedy) RS232 lines of communication, both full-duplex, from say a 16C74a. One line would go to a PC connected to a wireless network, and the other is connected to several IC's. I need some sort of asyncrohnous serial MUX or something. Any ideas anyone? How about a different micro-C? I know there are some new Microchip controllers that have two discrete UART's, but I could never afford to use those at this stage. Thanks. -- Garrick Kremesec Beckman Institute - RA http://www.cen.uiuc.edu/~gkremese gkremese@uiuc.edu