This mini-series of articles describes how to build a computer’s CPU (central processing unit) out of relays. “Y” in English sounds like “guay” in Spanish (my mother tongue), a colloquial expression ...

We’ve seen our share of blinking light projects around here; most are fairly straightforward small projects, but this entry to the 2025 One Hertz Challenge is the polar opposite of that approach.

[Tadao Hamada] works for Fujitsu Tokki, a subsidiary of the more famous Fujitsu. In 1956, Fujitsu decided to compete with IBM and built a relay-based computer, the FACOM128. The computer takes up 70 ...