This prototype consists of a keyboard wired to an array of vacuum tubes. The combined measurements do not include wires and plugs. The keyboard measures: 28 cm. w. x 34.5 cm. d. x 23 cm. h. The array of tubes measures: 48.2 cm. w. x 50.5 cm. d. x 26.7 cm. h. The keyboard resembles 1991.0190.05. There are three rows of black keys in front. These resemble a QWERTY keyboard, with a "." key instead of an "S". There is a space bar below the keys, with "SHIFT (/) LOCK" and "SHIFT (/) KEY" keys on the right. The keys are linked to electrical contacts. Some wires attach to a squat cylinder mounted horizontally on top of the machine. A capacitor is behind this cylinder on top, a motor to the left. Other wires are connected to a panel on the front of a large metal box. Holes in the top of the box hold a 5x5 array of vacuum tubes. There are three more tubes in back of the array, one smaller than the others. There is a condenser on each side of these three tubes. In back of these is a row with two large transformers on each side, a choke, and a small transformer. A back panel attached to the box contains a switch, a light and an ammeter. A large round plug is attached to numerous wire coming out of the box. A cord with smaller round plugs at each end fits the keyboard on the right side. The end of the plug that fits into the keyboard has a torn slip of paper around it. At the other end is tied a second torn slip of paper. A third, two-pronged plug extends from the keyboard and has a paper label tied around it.