"In a few museums around the world, there lies the special experience of seeing
some of the earliest computers. These room-filling monsters have multiple racks
of vacuum tubes that are kept working by the dedication and care of their
volunteer maintainers. A visit to the primordial vacuum tube computer, Colossus
at Bletchley Park, UK, led [Mike] on the path towards designing an entirely new
one. He thinks it’s the first to see the light of day in over five decades.
ENA, the Electron tube New Automatic Computer, is the result.
It uses 550 Soviet 6N3P double triodes, and its 8-bit Von Neumann architecture
is constructed from the tubes wired up as 5-input NOR gates. ROM is a diode
matrix, and RAM comes courtesy of reed relays. The whole thing is assembled as
eleven PCBs on a wall-mounted frame, with a console that holds the piece de
resistance, a display made from an array of LEDs. A Pong game is in
development, meanwhile the machine makes an impressive room heater."
Share and enjoy,
*** Xanni ***
Chief Scientist, Xanadu
Partner, Glass Wings
Manager, Serious Cybernetics