The earliest electronic computers such as ENIAC or Colossus needed wartime budgets and filled entire rooms. A hobbyist known as Mike has gone the opposite route, building a working vacuum tube computer compact enough to mount on a wall at home. The project is documented on hackaday.io as project 206568 and in full detail on the dedicated site thetubecomputer.com.

The machine is an 8-bit design following a von Neumann architecture with 16 instructions. Its block diagram would look familiar to anyone who has worked with a 1970s-era 8-bit microcomputer. The logic uses a NOR-based design, the same approach found in the Apollo Guidance Computer that NASA flew during the Apollo program. For the core logic, Mike used former Eastern-bloc double-triode vacuum tubes, while more modern components handle the input and output circuitry.

Despite the vintage tube technology inside, the finished unit is physically compact and wall-mounted rather than room-filling. It comes paired with an ex-British Rail flip-digit display and a control panel that runs a simple airship simulator game.

Hackaday's Jenny List singled out the build as a strong candidate for the 2026 Hackaday Retrocomputing Challenge, announced on August 18, 2026.