The Pocket Calculator at 40 Years Old

It's hard to peg a date on the actual anniversary of the handheld calculator's invention (initial development began around September 1965), but September 29, 1967, looks like a good date to celebrate: That's when Texas Instruments scientists Jerry D. Merryman, James Van Tassel, and Jack Kilby filed their patent for the first handheld calculator ever made. It was 40 years ago this week; now's a good time to sit back and remember the invention that ultimately made the slide rule obsolete and paved the way for the personal computer.

Texas Instruments' project was in response to frustration with the state of the art in calculator technology: At the time, desk calculators weighed about 55 pounds, were the size of a typewriter, and had to be plugged into wall power.

The original handheld (pictured) was completed in 1967, complete with 12 bytes of memory, battery power, and a mere three pound heft. Unlike today's scientific marvels, the original calculator had only the four basic math functions: add, subtract, multiply, and divide. (Don't miss the thermal "ticker tape" printer, too!) TI would not receive that patent for the "Cal Tech" calculator until 1974 (after a seven year wait). Though initially very expensive, by the early 1970s, calculators cost only $100 to $300, rapidly dropping to commodity prices by the end of the decade.

Naturally, TI is today taking the opportunity to announce new products that show just how far we've come: The new TI-Nspire line is more computer than adding machine, complete with formula management features, advanced graphing functions, and even a word processor. Even if you have no need for a calculator any more, these new models are still a marvel to look at (at least if you're a tech geek like me).

Congrats, TI, on giving us one of technology's most essential products and sticking with it for all these years.