Linking multiple boards to be run from a single controller

We have been left with 2 AX1500 controllers from the team that previously worked on the bot. Each controller is capable of running 2 motors. Our bot thus far will be running at least 3 possible 4 and we are trying to find a simple method of controlling both boards. We are hoping that we might somehow use the roborun software to control both boards, for example perhaps running two instances simultaneously, most likely connected to a configured joystick. What I am hoping is that you might have a more simple solution. The essential goal is these 3 motors will be driving motors for the bot. I suppose the overall question is if there is a simple method to link multiple boards together and run them from a single controller?

Controlling two boards it is easy if you have a computer with two RS232 boards. You can purchase USB dual RS232 boards for 40 dollars. All you have to do is to write your software issuing commands to COMM1 and COMM2.