well, if you still have this thread subscribed, your linux box should have all that is necessarry to communicate with you wyse terminal SOFTWARE wise, but you need a serial null modem cable (or a null modem adapter)
but really, once you have that hooked up, all you have to do is add a line in your /etc/termcap file
sX:2345:respawn:/sbin/getty /dev/ttySX dt*baud rate* wyxx
where X is the serial port number
and wyxx is the protocol used cheers