In the early 1970s, the daily lives of people throughout the developed world were changed profoundly by the advent of a small electronic machine that could per-form basic mathematical problems much more quickly and more accurately than they could be worked out on paper. Calculators expanded the math capabilities of everyone from high school students to businessmen.

The original compact calculator was the abacus, developed in China in the ninth century. The young French mathematician Blaise Pascal (1623-1662) invented the first adding machine in 1642, a clever device driven by gears and capable of performing mechanical addition and subtraction. The first commercially successful adding machine was developed in 1886 by William Seward Burroughs (1855-1898). The "Millionaire," a machine invented by Otto Steiger in 1894, was the first adding machine also capable of direct multiplication.

This was followed by major developments fundamental to MOS/LSI integrated circuitry - the basic technology behind today's miniature calculators. Two key patents on MOS/LSI were awarded to TI in 1972.  A third significant milestone was the introduction by TI in 1971 of the "calculator-on-a-chip" MOS/LSI circuit which became the heart of modern, miniature calculators.

The miniature calculator described in the new TI patent was the result of work done at TI in the mid-60s. The patent (Number 3,819,921), originally filed in 1967, was awarded to TI June 25, 1974. This miniature calculator (the world's first) employed a large-scale integrated semiconductor array containing the equivalent of thousands of discrete semiconductor devices. Measuring 4-1/4 x 6-1/8 x 1-3/4-inches, it was the first mini-calculator to have the high degree of computational power found only at the time in considerably larger machines.

The working heart of the first miniature calculator was an integrated semiconductor circuit array that contained all the necessary electronics for performing addition, subtraction, multiplication, and division. Other elements of this early example of the miniature calculator included a small keyboard with 18 keys and a visual display in the form of a semiconductor thermal printer for printing out calculations of up to 12 decimal digits.

Since the invention of this first miniature calculator, semiconductor technology has had a dramatic impact on the electronic calculator industry with ever-decreasing prices characteristic of this new breed of computational machines. These price reductions have been a result of advances in solid-state technology and economies of large-scale calculator manufacturing.

Evolving over the years since 1966 has been a trend toward more complex calculator integrated circuits with resulting semiconductor economies and lower prices to end-use customers. The 1966 business calculator version retailing for $2000 contained over a thousand discrete semiconductors such as transistors and resistors with a cost of $170.

In 1968, integrated circuits (ICs) began finding their niche in business calculators with a typical selling price of $1000. These initial IC models had 90 ICs at a cost of $125. Integrated circuit application, therefore, reduced the cost of parts as well as having a substantial impact on parts handling and assembling.

With the advent of MOS/LSI in 1970 early portable calculators using more than one major IC and priced at around $300 to $500 were produced using LSI circuits. TI's single MOS/LSI "calculator-on-a-chip" IC in 1971 heralded the age of the low-cost consumer handheld calculator and ignited the burgeoning electronic calculator market.

RELATED INVENTIONS:
History of Computing   from The Great Idea Finder
Jack Kilby, Inventor Profile     from The Great Idea Finder

ON THE BOOKSHELF:
100 Inventions That Shaped World History
by Bill Yenne, Morton, Dr. Grosser (Editor) / Paperback - 112 pages (1983) / Bluewood Books 
This book contains inventions from all around the world from microchips to fire. This is a really good book if you are going to do research on inventions.

ON THE WEB:
History of Innovation at Texas Instruments
Electronic Hand-Held Calculator
(URL: www.ti.com/corp/docs/company/history/calc.shtml)
The Museum of HP Calculators
The Museum of HP Calculators displays and describes Hewlett-Packard calculators introduced from 1968 to 1986 plus a few interesting later models.
(URL: www.hpmuseum.org/)
Texas Instruments Introduction
Much to see at the chip collection of the Smithsonian National Museum of America.
(URL: smithsonianchips.si.edu/texas/tirefer.htm)
Vintage Calculators Web Museum
A celebration of old calculators showing the evolution from mechanical calculator to hand held electronic calculator.
(URL: www.vintagecalculators.com/)
Education World
On-Line Math Tools -- and Activities to Use With Them!
(URL: www.education-world.com/a_lesson/lesson124.shtml)

WHERE TO FIND:
TI83 PLUS Graphic Calculator
byTexas Instruments / ASIN: B00001N2QU / Less than $100
The addition of the optional TI Graph-link (software and cable) allows you to connect the calculator to your computer, permitting the transfer of files and data between machines.

DID YOU KNOW?

• The pocket calculator went on the market on September 21, 1972, as the TI-2500 and was capable of addition, subtraction, multiplication and division. It had a floating decimal point and an eight-digit, light-emitting-diode (LED) display. The Tl-2500 measured 5.5 x 3 x 1.7 inches (14 x 7.6 x 4.3 cm) and weighed 12 ounces (.34 kg). The original TI-2500 retailed for $120, but within a few years equivalent machines were retailing for under $10.
• Even for the public-at-large, the calculator made an impressive impact. It was one of the earliest direct exposures to digital electronics, and, in retrospect, can be seen as a prelude to the age of the personal computer. Indeed, the famous story is told of how Steven Wozniak sold his Hewlett-Packard programmable calculator to scrape together enough money to launch Apple Computers.