RS485 Communications

I have a PC104 SBC that has onboard RS485 ports.  I previously wrote
standard RS232 comm port routines to talk to devices on the rs485 network by
using a 232 > 485 convertor and everything worked great.  Now, however, I
want to use the onboard 485 ports.  I have two questions....

1, my port is a 4 wire, my network is a 2 wire.  This is how I converted.
+TX & +RX Tied together,  -TX & - RX Tied together.    The -TX & -RX hook to
A on the Network, and the +TX & + RX hook to B on the network.  Is this
correct?


2.  In my standard Rs232 Routines, I modified to simply Raise RTS, wait 10
ms, then then the string, wait 10ms, lower RTS.
     I don't do anything special at all waiting on chars to arrive.

Problem is, none of this works.  Any pointers?  I assume I can use the
standard Serial Port Routines if I turn off  All flowcontrol and use the RTS
line right?


I find tons of info on the difference in the specs, but not much about
writing to the ports.

Richard