If I duplicated a message to cctech, my apologies; what I meant to send was: I just confirmed that my recollection was correct and that the AIM65's TTY I/O is effectively RS-232 compatible. I connected an AIM65 to 3 different computers and they all communicated just as is, i.e. without any level conversion. Needless to say this assumes that the distance is fairly short. Just connect ground, J1-Y and J1-U to RS-232 ground, TX data & RX data respectively and if your RS-232 port is like mine, away you go. If you have trouble with autobaud, set the baud rate manually at A417/18 before switching to TTY. (Set the terminal/computer to 7 bits). Unfortunately the KIM-1 doesn't seem to have an RS-232 compatible serial input, so you'll have to add a limiting resistor & two clamping diodes and connect to U15-12 as the AIM does. mike