Chainable additional voltage outputs for Turing Machine. Doesn't need it's own power. Fits both old (Mk I) and new (Mk II) Turing Machines; old ones need the backpack, new ones don't. The normal Turing Machine output is weighted to the right as most significant. The VOLTS takes the leftmost five bits of the display. You can also set the weight of each bit independently. That changes the sound significantly (and nicely!). Built locally by Bill Lynes.