Actually, this is a boring device. It's an integral part of the Story Teller system, and is quite useless without it.
Left to itself, the Story Teller would merrily read it's paper tape and perform the story, clattering and yacking away until the tape ran out, as it is supposed to. But in an art gallery that's not practical, as I quickly found out; it annoys the staff, and no one wants to constantly rewind huge reels of paper tape.
So the Model 7 Gallery Controller sits on the WPS standard serial buss (ooh techie-talk) and controls the performance. It contains a tiny computer, and a lighted pushbutton switch. Basically, it sits there waiting for you to push the switch, tantalizingly blinking it's yellow lamp. Until that happens, it tells the Story Teller buss to halt, stopping the Tape reader, pausing the performance. When you push the switch, the light goes out, to hint you should stop looking at it at pay attention to the story. It lets the story run for about 3 - 4 minutes, then stops the story, and goes back to it's lamp-blinking idyllity.
No, it's not just a silly timer, there's a catch: to pause the performance cleanly, the Model 7 has to know about the WPS standard ASCII data stream. When the timer runs out and it's time to stop the story, the Model 7 looks for the end of the next data record, and only then halts the buss. It also has to know about buss errors (like when you physically remove a tape in the middle of playing). Hence the little computer that has to worry about all this, and so it can't be a simple timer.
If this sounds overly complicated, it's not, its the absolute minimum complexity necessary to get the job done. Complexity and richness of function are good, not burdens. Simple is not always better. For example, there are an infinite number of vastly simpler, "more efficient" protocols than TCP/IP, which the internet is built upon, but they aren't complex enough to deal with the real world.
Anyways I digress. The WPS data stream handles broken tapes, bit errors, slow and fast (sic) devices on the same buss, and a bunch of other real-world problems.
And the real beauty of standardized protocols is that all of the boxes are independent; I was able to make the Model 7 back at home, after Story Teller was installed in the OUTWEST show, tested it on the bench only, shipped it to Santa Fe where Scot plugged it in, and it worked first time.
You may be interested in a more technical description of Story Teller, it's development, other federated components, and the software that produces the tapes. In case you're interested in what's inside the Model 7 (not much, I assure you), take a gander at this, this, and this. For utter tediousness, here is the back.
Mixed media, 5"w x 3"h x 7"d, approx.