I have an x86-based Linux box with 16550A serial ports (it is a fairly new machine). Or at least setserial claims that they are 16550A's. My OS is RedHat 4.2. I'm using PPP 2.2.I'm trying to connect to my extern ISDN modem (AdTran XRT) at 230.4k. The modem end is easy -- just a DIP switch. But I cannot chant the right incantation to make Linux set the serial port to 230k. I've tried putting things like this in rc.local and/or the ifup-pp script: setserial /dev/cua0 baud_base 230400 divisor 1 spd_custWhen I do that (and set the modem for 230k), they do not talk anymore. Does anyone know the right formula?