Moth in Relay

In 1947 a moth was found in a relay switch on the Mark II electromechanical computer, a true computer "bug." What's most interesting here isn't that an insect was found in the machine, but that the computer operator taped the moth into the logbook. It's almost as if the moth was trapped in a thin sheet of amber, preserved as the pre-digital ancestor of the tricksters within our own modern devices. 

Photo of a moth taped in a log book.

The insect was found by Grace Hopper (Wayback Machine link), a computer scientist and rear admiral in the US Navy. Google recently paid homage to Hopper with a "doodle" (below) showing her working on an early mainframe computer. Not only does the computer display an answer on a paper printout, but a moth also flies out at the end of the sequence.

Google Doodle showing Grace Hopper at a mainframe computer.

(Revised and republished April 19th, 2025)

The "3000-pound spreadsheet machine"

If It Ain’t Broke, Don’t Fix It: Ancient Computers in Use Today (Wayback Machine link)

Companies traditionally used the 402 for accounting, since the machine could take a long list of numbers, add them up, and print a detailed written report. In a sense, you could consider it a 3000-pound spreadsheet machine. That’s exactly how Sparkler Filters uses its IBM 402, which could very well be the last fully operational 402 on the planet. As it has for over half a century, the firm still runs all of its accounting work (payroll, sales, and inventory) through the IBM 402. The machine prints out reports on wide, tractor-fed paper.

This is pretty amazing. I’ve seen older systems in use recently, like Windows 95, but this is just extraordinary.

Damaged punch cards.

(Revised and republished April 21st, 2025)