Looking inside a vintage Soviet TTL logic integrated circuit

Ken Shirriff examines a 1980s chip used in a Soyuz space clock: The clock is built from TTL integrated circuits, a type of digital logic that was popular in the 1970s through the 1990s because it was reliable, inexpensive, and easy to use. (If you’ve done hobbyist digital electronics, you probably know the 7400-series of […]