Four hundred sixty tubes, and the software it runs is an airship flight sim.
Mike’s Tube Computer is an 8-bit machine built on NOR-based logic, the same approach Hackaday points out the Apollo machines took, with eastern bloc double-triodes doing the work and more modern parts handling the I/O. His site puts it this way:
A modern 8 bit design, built with recycled 1950s vacuum tubes, that glow and heat the entire room.
His Hackaday.io page has the parts list: 460 6N3P dual triodes (920 triodes), 1840 germanium diodes, 2300 resistors and 460 trimmer pots. I did the division. That’s four diodes, five resistors and one trimmer per tube, which tells you how much adjusting aging 1950s glass needs. The page hopes the tubes become active NOR gates after a few minutes, and the project site says ten minutes to thermally stabilise.
He says he wanted to see whether a modern design could beat the size, power and high-voltage dangers of the old tube machines. That’s the right question, and it’s why this is a win: he built the thing to answer it instead of copying a museum piece. So far it runs a 64-bit Fibonacci sequence and a flight sim of the R80 airship at Brighton Aerodrome. The tube RAM is five boards, the clock is being redesigned and the console is unfinished.
The Hackaday.io page lists no files or repo, so as far as I can tell you can’t build one from what’s posted. Finding 1840 1N33A diodes sounds like the harder shopping trip to me anyway.