The IBM ® 700 series was the company’s first line of production business computers, but the machines were also an important transition for computing. Beginning in 1952, the 701 and its successors were built as systems, developing the concept that speed involved more than just processing, but also memory, input and output. The 700 series was also a bridge from vacuum tube electronics to transistors.
As the 1950s unfolded, 14 US companies were developing electronic computers with help from the government. The Cold War prompted US President Harry S. Truman’s administration into pumping money into technology in hopes of maintaining an advantage. Some of that money went to university labs. Some went to start-up companies like Engineering Research Associates. And some went to ENIAC developers J. Presper Eckert and John Mauchly, who found a backer for their business in Remington Rand. The duo built a commercial successor to their ENIAC, dubbed UNIVAC—the first electronic computer to win the hearts of the new generation of scientists who adored the high-speed calculations these computers made possible. Under pressure from UNIVAC, IBM engineers felt that their pride—and possibly an important part of IBM’s future—was at stake. The culture responded in a surge of esprit de corps and created a system geared for speed: the IBM 701 Defense Calculator.
The 701 design team couldn’t wait for the space it needed inside IBM, so it started work on the third floor of a tie factory in Poughkeepsie, New York, then moved to an empty supermarket building. “Tar leaked down from the roof on hot days,” said Clarence Frizzell, one of the project managers. “We had to scrape it off the drawings to keep working.” The team threw aside budgets and schedules, previously a fact of life in the labs. “Maybe that’s why we did things so fast,” said Jerrier Haddad, a managing engineer on the 701. “We didn’t have schedules to slow us down.
In a little less than two years, the team developed and began building the enormously complex machine, known as the Defense Calculator only in development. It featured a number of breakthroughs in design. The Defense Calculator became the IBM Model 701 Electronic Data Processing Machine, a scientific computer that could perform more than 2000 multiplications per second, nearly 50 times faster than a preceding model, the IBM 603. But the processor was only part of the speed equation. Memory—the ability to fetch and store information for the computer to work on—was the weak point in early computers. The main memory of the 701, based on electrostatic devices called Williams tubes, could hold just over 20,000 digits, about one one-thousandth of a percent of the memory that in 2011 is standard in a US$300 notebook computer. The main memory was supplemented by a bigger but slower magnetic drum—a sort of primitive disk drive—that held 82,920 digits, and even slower magnetic tape units that held 8 million digits per reel.
IBM had 10 confirmed orders but ended up making nineteen 701 machines and leasing them for about US$15,000 a month (about US$120,000 in 2011 dollars). The first 701 was installed in IBM’s world headquarters on Madison Avenue in New York. Three went to atomic research laboratories, eight to aircraft manufacturers, three to other research facilities, and two to government agencies, including the US Department of Defense. The last 701 made was leased to the United States Weather Bureau in early 1955.
The combination of electronic processing and electronic memory made a machine that amazed the world. Time magazine noted that a business-oriented version of the 701, the 702, could “remember enough information to fill a 1,836-page Manhattan telephone book … and work the information at the rate of 7,200 unerringly logical operations per second. …. it can multiply a pair of 127-digit numbers and arrive at a 254-digit answer in one-third of a second.” This kind of systemic speed spurred scientists to imagine what they could do with faster and more complex data. Time wrote that chemists at Monsanto felt the machine would “open up new horizons by rapidly working out complex equations to help discover new products, improve old ones, find out which of dozens of technically ‘correct’ answers to problems are the best.”
The 700 series evolved over more than a decade. The 704 was a 701 with an upgraded memory, floating-point arithmetic and updated software, and IBM sold 123 of them from 1955 to 1960. The 705 and then the 709 succeeded the 704. In the late 1950s, IBM developed the 7090, which was basically a 709 but built with transistors instead of vacuum tubes. The 700 and 7000 series were IBM’s high-end computers until the arrival of the IBM System/360 in 1964, and presaged IBM’s strength in the mainframe computer market that continues today.