I was wondering if someone could help me figure out how to implement the following setup. I'm working on a project where I need to talk multiple RS232 devices with a micro controller configuration. I say configuration because, if necessary, I can use multiple micro controllers with built in RS232 ports, however this is not desirable as I would like to keep power consumption and number of parts as low as possible. Another useful feature would be the ability to share a connection to an RS232 device.

The main problem I'm having is trying to connect multiple serial devices to a uController. I've been working with a MINI-MAX-51/C2 board from BiPom (ATMEL AT89C51ED2), and it and most other boards I've seen only have one RS232 port built in. Given the limitation of ports, I'm quite confused about how to do this. Do uControllers exist with multiple RS232 ports on one board? I know it is possible to emulate a UART connection in software, but would this be the best route? I should probably also mention that although the current setup only needs to connect to 2 devices, it will need to be able to connected many more (possibly 7). Any suggestions?

As for wanting to share connection to an RS232 device, the uController is also connected to a Windows PC (via either RS232 or Ethernet, haven't decided yet) and it would be nice if the PC could have a seemingly direct communication with the devices. Whether this calls for actively switching control of the connection between the uController and the PC or just having the uController relay data to and from the PC is up for debate. In either case, the software on the Windows PC is going to be looking for COM ports so I would have to emulate/present them somehow.

Any suggestions or info would be much appreciated. Thanks in advance.