-19200, 38400, 57600, or 115200. Your hardware may limit your baud
-rate choices.
+19200, 38400, 57600, or 115200. The hardware implementation of your
+serial interface card may limit your choice of baud rates. To be precise: the
+frequency of the baud rate clock signal fed into the NSxx50 chips determines
+which baudrates you can select, not the NSxx50 chips themselves.
+.Pp
+All I/O addresses and IRQ levels listed in the config file must
+exactly match the actual setup of the hardware. Note that the AT bus
+does not support multiple cards on a single IRQ line.