From room-sized to shirt-pocket — the electronic devices that made slide rules obsolete (1957–1973)
In barely sixteen years, electronic calculators shrank from relay-filled cabinets that filled entire desks to pocket-sized marvels that cost less than a textbook. Along the way, they destroyed an industry (slide rules), created another (consumer electronics), and put computational power into the hands of millions. These seven interactive recreations let you press the keys, watch the displays glow, and experience the machines that changed how humanity does arithmetic.
The first generation of electronic calculators replaced mechanical gears and wheels with relays, vacuum tubes, and transistors—filling entire desktops but computing in seconds instead of minutes.
The Kashio brothers' relay-based marvel: 342 clicking relays computing 14 digits. Watch the relay banks flip as you calculate on the machine that launched Casio.
"A New Inspiration To Arithmetic"—the first all-electronic desktop calculator. Type numbers and watch Nixie tubes glow orange as cold-cathode circuits count.
The first all-transistor calculator with a CRT display. Four green phosphor lines show all registers simultaneously on an oscilloscope-like screen.
530 transistors, Nixie tube display, and a $4,130 price tag—more than a car. Experience the machine that put Sharp on the map.
One machine bridged the gap between calculator and computer—and NASA used it to reach the Moon.
When calculators fit in a shirt pocket, the slide rule died overnight. These two rivals started the war that would put a calculator in every home.
The calculator that killed the slide rule. Full RPN stack, scientific functions, and the iconic blue/orange keys. Bill Hewlett's "shirt pocket" challenge made real.
Texas Instruments' "electronic slide rule" at half the price of HP-35. Red LED display and a side-by-side slide rule comparison mode.