I am attempting to evaluate RobotC running on an Intel iMac running Windows XP under Parallels. I cannot seem to get RobotC to recognize the USB tower attached to the virtual machine. Has anyone been successful in this?

A more general question: Does RobotC support the old serial towers?

Tim would be better answering the MAC VM question, however, when I'm running VMWare with ROBOTC I am able to have it recognize the tower when I go to VM -> Removeable Devices and find the LEGO tower to enable it. I'm not sure if you're using VMWare as well (I'm not the MAC-expert).

For your second question, are you talking about the LEGO RCX Serial-IR towers? If so, then yes it works. That's how we transfer the programs to the RCX. Keep in mind that you must have the LEGO Tower drivers installed for it to work.