The Tube Computer MK3: 8-bit machine built with 460 vacuum tubes

An electronics enthusiast named Mike has developed ‘The Tube Computer MK3’, an 8-bit computer constructed using 460 salvaged Soviet 6N3P vacuum tubes. Mounted on a wall within an aluminum frame, the device measures 190 by 130 centimeters and operates without microprocessors or integrated circuits, relying instead on tube-based logic.

The system utilizes an architecture where each instruction undergoes a six-step fetch cycle followed by an execution cycle. Its arithmetic-logic unit performs essential functions including addition, carry, negation, increment, and XNOR. Currently, the computer runs a custom ‘Airship Simulator’ software, allowing users to pilot a British R80 airship from Brighton to Paris via membrane buttons.

Due to the nature of the vintage components, the machine requires significant maintenance. The vacuum tubes have an estimated operational life of approximately 500 hours, and the system requires a 10-to-15-minute warm-up period and a mandatory reset upon powering on. The scale of the wall-mounted installation is such that a ladder is required to perform repairs.