ITH
IT History Journal
March 29

March 29, 1967 — The First Handheld Calculator Debuts

March 29, 1967

On this day, Texas Instruments unveiled the prototype of the first electronic handheld calculator known as Cal-Tech.

Before handheld calculators

Engineers had two main options besides doing calculations by hand:

  • mechanical calculators and slide rules
  • large desktop electronic calculators

By 1967, there had already been noticeable progress in desktop calculators. The mid-twentieth century marked a period of explosive growth in electronics and computing technology.

The idea of a handheld calculator

Beyond the obvious advantages of making electronic calculators smaller, Texas Instruments had another strong motivation: the company was actively advancing integrated circuit technology.

Creating a consumer product would clearly demonstrate the potential of integrated circuits:

  • smaller device size
  • lower power consumption
  • lower price compared with desktop machines

For this reason, Texas Instruments began actively working on a handheld calculator project in the mid-1960s.

Prototype demonstration

On March 29, 1967, the Cal-Tech (calculator technology) prototype was demonstrated to partners and electronics manufacturers.

The device was much larger than modern pocket calculators, but significantly smaller than any desktop calculator of its time.

During the presentation it was shown that the calculator could:

  • accept numbers through a keyboard
  • print results on a paper tape
  • perform addition, subtraction, multiplication, and division
  • operate completely independently without a power outlet — a major breakthrough for the product

Who worked on the prototype

  • Jerry Merryman — the author of the idea
  • Jack Kilby — lead engineer and inventor of integrated circuit technology
  • James Van Tassel — responsible for hardware design

From prototype to commercial products

The Cal-Tech prototype was primarily intended to demonstrate the capabilities of integrated circuits.

The next step was to secure a patent for a “Miniature Electronic Calculator” and begin working with manufacturing partners to create the first commercial versions of the device.