If neither device support an alternate IR address mode, then you need the 890 with its device addressable extender ports. With the 880, the best you can do is leave one device on and the other off. Then use use the PowerToggle command (mapped to a key in your activity) to select which device to control. You should also change the Adjust power settings of both devices to use the toggle method (One button on the remote for turning it both On and Off), else both units will turn On or Off at the same time with the default discrete powering method.