Every device needs...

A potentiometer dial. Big, with a thumb depression or folding winding arm.

<8in CRT display. Preferably with indecypherable graphs. Yes, the lawnmower, too.

A full tape deck with record because you might hear that one bop on the radio and all you have is your hairdryer.

3.14in floppy drive or some form of microdisk if the device is too small.

Beige or steel-gray. Options for accents of black, white, or red.

Boxy, injection-molded shell.

Antennae.