Split comic panel: a 1950s relay room full of black relays and glowing tubes with a technician in a fedora on the left, a slim modern controller cabinet with a circuit board and laptop on the right, and the ErrorZap host standing between them under a caption reading 1955 vs NOW.

From Relay Rooms to Circuit Boards

Elevator control went from human operators to rooms of clicking relays to microprocessors and VFDs. What each generation decided and how the modern stack is wired.

September 26, 2026 · 5 min · 930 words · Justin