Image 10: Keyboard underside close-up

Those "channels" are interesting; I doubt you'll find the same in any other computer. The cable fits snugly in there – er, more or less, that is; it doesn't want to neatly "snap" in at all spots. And after you've played with it once, you'll want to leave it alone; pushing the cable into the the channel is a pretty clumsy process, not really a "plus" in the TAM experience.

Still, something is needed to keep that cable from pooling in an ugly way beneath the keyboard, which would also prevent the keyboard from lying flat when its feet are turned up. Hence a channel.

Why a channel on both left and right? It wouldn't seem necessary - except that you might have a preference for which side you'd like to attach the trackpad, in case you want to use it separated from the keyboard, and/or want to plug a mouse into a specific side. Hence two channels.

Whew! A lot of work went into that keyboard underside. (And I wonder: Was it one of the last TAM parts designed? The clue is the modern, all-white Apple logo you see there, whereas the rest of the TAM sports the old rainbow logo. Does the keyboard underside intentionally point to the Apple logo transition that began shortly afterward?)