page_title: Ed Roberts (computer engineer)
section_title: Calculators
hierarchical_section_title: Ed Roberts (computer engineer) / Calculators
caption_attribution_description: English: Micro Instrumentation &amp; Telemetry Systems, Inc (MITS) advertisement for an electronic calculator in June 1972. After a brutal calculator price war in 1973–1974, MITS was $300,000 dollars in debt. The company introduced the Altair 8800 in January 1975, the first successful personal computer. MITS was acquired by Pertec Computer Corporation in 1977 for $6 million.
context_page_description: Henry Edward "Ed" Roberts was an American engineer, entrepreneur and medical doctor who invented the first commercially successful personal computer in 1974. He is most often known as "the father of the personal computer." He founded Micro Instrumentation and Telemetry Systems in 1970 to sell electronics kits to model rocketry hobbyists, but the first successful product was an electronic calculator kit that was featured on the cover of the November 1971 issue of Popular Electronics. The calculators were very successful and sales topped one million dollars in 1973.
  A brutal calculator price war left the company deeply in debt by 1974. Roberts then developed the Altair 8800 personal computer that used the new Intel 8080 microprocessor. This was featured on the cover of the January 1975 issue of Popular Electronics, and hobbyists flooded MITS with orders for this $397 computer kit.
  Bill Gates and Paul Allen joined MITS to develop software and Altair BASIC was Microsoft's first product. Roberts sold MITS in 1977 and retired to Georgia where he farmed, studied medicine and eventually became a small-town doctor living in Cochran, Georgia.
context_section_description: Roberts's first real experience with computers came while at Oklahoma State University where engineering students had free access to an IBM 1620 computer. His office at the Weapons Laboratory had the state of the art Hewlett-Packard 9100A programmable calculator in 1968. Roberts had always wanted to build a digital computer and, in July 1970, Electronic Arrays announced a set of six LSI integrated circuits that would make a four-function calculator. Roberts was determined to design a calculator kit and got fellow Weapons Laboratory officers William Yates and Ed Laughlin to invest in the project with time and money.
  The first product was a "four-function" calculator that could add, subtract, multiply, and divide. The display was only eight digits, but the calculations were performed with 16 digits precision. The MITS Model 816 calculator kit was featured on the November 1971 cover of Popular Electronics. The kit sold for $179 and an assembled unit was $275. Unlike the previous kits that MITS had offered, thousands of calculator orders came in each month.
  The monthly sales reached $100,000 in March 1973, and MITS moved to a larger building with 10,000 square feet (930 square meters) of space. In 1973, MITS was selling every calculator that they could make, and 110 employees worked in two shifts assembling them. The functionality of calculator integrated circuits increased at a rapid pace and Roberts was designing and producing new models. The popularity of electronic calculators drew the traditional office equipment companies and the semiconductor companies into the market. In September 1972, Texas Instruments (TI) introduced the TI-2500 portable four-function calculator that sold for $120. The larger companies could sell below cost to win market share. By early 1974, Ed Roberts found that he could purchase a calculator in a retail store for less than his cost of materials. MITS was now $300,000 in debt, and Roberts was looking for a new hit product.
caption: June 1972 advertisement for MITS Model 1440 Calculator
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