The first functional prototype, pictured above, was created in 2009.

By 1973, the two engineers successfully produced a functional prototype.

Wireframes often provide the basis for more functional prototypes - once the basic design has been agreed.

The most promising clay version was used to make a functional prototype.

In this way, fully functional prototypes of systems, including the user interface, can be developed directly from their specifications.

Whether there really is a functional prototype out there somewhere.

It was a completely functional prototype that never made it into production.

The functional prototype was created on the end of 2005.

The functional prototype may be reduced in size (scaled down) in order to reduce costs.

A data prototype is a form of functional or working prototype.