I gave myself two challenges here, to make a nice enclosure and to create a minimalist UI.

The laser-cut enclosure uses two materials and echoes the circular LED ring and encoder knob.

The UI is just the ring and the encoder.  The ring represents the tape and the encoder moves a cursor around it.  Clicking the built-in push-button switches to the Editor, from which a symbol colour can be chosen, along with menu items.  The menu items let you define a Machine and give access to a number of other features including:

• Load some baked-in example machines (eg binary add)
• Move machines to and from EEPROM
• Read/Write machines to serial.
• Configure speed, brightness etc
• Switch to a clock mode!

More photos on flickr

Thanks to Zafar for the inspiration!