Thanks for the response gonk and cruise. If the port is for playback only (which makes sense, actually), then I have a problem. I have a device that connects to my computer to input and output RCA jacks in the back of the receiver so that the computer can behave just like a cassette player. The problem with the 2150 is then, of course, the fact that it only can accommodate one such recording device. I'll need to either choose between my computer or cassette player, swap the cords when I want to switch, or rig-up some workaround to allow me to switch on the fly.

If I'm completely honest, though, it's very unlikely I'll be recording cassettes any time soon. I'll probably just hook the computer up to the tape input/output jacks and run the output from the cassette into one of the other inputs.