Making Things Talk

IDENTIFICATION 301

Designer Durrell Bishop’s marble telephone answering

machine is an excellent example of the challenges of identi-

fying physical tokens. With every new message the machine

receives, it drops a marble into a tray on the front of the

machine. The listener hears the messages played back by

placing a marble on the machine’s “play” tray. Messages

are erased and the marbles recycled when the marble is

dropped back into the machine’s hopper. Marbles become

physical tokens representing the messages, making it very

easy to tell at a glance how many messages there are.

Bishop tried many different methods to reliably identify and

categorize physical tokens representing the messages:

“I first made a working version with a motor and large

screw (like a vending machine delivery mechanism), with

pieces of paper tickets hung on the screw and had different

color gray levels on the back. When it got a new message

the machine read the next gray before it rotated once and

dropped the ticket.

It was a bit painful so I bought beads and stuffed resistors

in to the hole which was capped (soldered) with sticky

backed copper tape. When I went to Apple and worked with

Jonathan Cohen we built a properly hacked version for the

Mac with networked bar codes.

Later again with Jonathan but this time at Interval

Research, we used the Dallas ID chips.”

Color by itself isn’t enough to give you identity ...