Hardware Flow Control

Hi,

I building a robotics system, and I need to get my mac to speak with an rs-485 network. I currently have a usb to rs-232 converter (Keyspan 19HS) which is working just fine.

I have been trying to implenment a converter from rs-232 to rs-485, but I have been unable to the the RTS and CTS to toggle the way that they should. I'm using minicom to send data to the serial port, and when I turn hardware flow control on, everything stops working.

I am aware that hardware flow control is not supported by all unix systems. Can I get my mac to use hardware flow control, or am I screwed?

Thanks

Bill