Editing IBM Future Systems project (section)

===370===
The [[System/360]] was announced in April 1964. Only six months later, IBM began a study project on what trends were taking place in the market and how these should be used in a series of machines that would replace the 360 in the future. One significant change was the introduction of useful [[integrated circuit]]s (ICs), which would allow the many individual components of the 360 to be replaced with a smaller number of ICs. This would allow a more powerful machine to be built for the same price as existing models.{{sfn|Case|2006|p=47}}

By the mid-1960s, the 360 had become a massive best-seller. This influenced the design of the new machines, as it led to demands that the machines have complete backward compatibility with the 360 series. When the machines were announced in 1970, now known as the [[System/370]], they were essentially 360s using small-scale ICs for logic, much larger amounts of internal memory and other relatively minor changes.{{sfn|Case|2006|p=54}} A few new instructions were added and others cleaned up, but the system was largely identical from the programmer's point of view.{{sfn|Case|2006|p=57}}

The [[recession of 1969–1970]] led to slowing sales in the 1970-71 time period and much smaller orders for the 370 compared to the rapid uptake of the 360 five years earlier.{{sfn|Pugh|1991|p=541}} For the first time in decades, IBM's growth stalled. While some in the company began efforts to introduce useful improvements to the 370 as soon as possible to make them more attractive, others felt nothing short of a complete reimagining of the system would work in the long term.{{sfn|Case|2006|p=57}}