Digital superconductive electronics: where does it fit?

Superconductivity has been pursuing the world of digital electronics ever since 1956. During all this time its supporters have emphasized the `obvious' advantages of `low power' and `unmatched device speed'. However, still no digital electronics product is in a system; silicon-based digital devices overwhelm all others in the applications world. This is true today, in spite of even faster superconductive devices and circuits as well as greatly reduced power. The major issues that must be faced and resolved in order to insert this immature technology into the market place are the following.