In the 1960s, IBM and other manufacturers were making mainframe computers and selling them to large banks and other corporations, and to governments. They contained large numbers of silicon chips, printed circuits, tape drives for storing data, and various peripheral devices. Each computer needed a large, air conditioned room to house it. The cost of each computer was millions of dollars. In the 70s, smaller, cheaper computers called mini computers emerged, although they still needed a lot of space and were expensive to buy.
六十年代，IBM 和别的制造业者生产着住架电脑， 给大银行和别的公司也给政府消过它们。这些大电脑包含很多硅片，印制电路，资料检索系统，也各种周边电子器件。需要摆每个电脑在一个大使用空调的大室里。每个电脑的价格是很多千万的元。七十年代， 更小， 更便宜的叫小型电脑的电脑出现， 但是它们还是需要很多空间，也很贵。
In 1971, Intel invented the microprocessor. Instead of using a great many chips, like an IBM machine, a microprocessor was a single silicon chip. Popular Electronics magazine commenced a search for the world’s first computer based on a single chip. In January 1975 the cover of Popular Electronics showed the Altair computer. This was a very basic device, and only had enough computer memory to store one small paragraph. However, Altair managed to sell computers totalling $13m in a single year.
1971 年， 英特尓发明了那个微处理器。这个器不根IBM电脑一样使用很多硅片，反而微处理器是单一硅片。流行电子杂志开始搜索世界第一只利用单一硅片的电脑。1975年一月流行电子包杂志显了河鼓二电脑。这是一个很简单的器，只包含够存储容量存一个小段。但是河鼓二一年的电脑消售总是九千万元。
Later, a very clever engineer called Steve Wozniac teamed up with Steve Jobs, who was not an engineer but was very excited about the possibilities of the new technology. Wozniac designed a very basic computer which was called the Apple, and then a more sophisticated machine with a screen and keyboard called Apple 2. This was the first really successful personal computer and sold many thousands of units world wide.
The success of the Apple 2 persuaded IBM that it needed to enter this new market, even though the selling price of each computer was a tiny fraction of the price of a mainframe computer. In order to complete the design, they needed an operating system to drive the chips and other devices in the machine. As they did not understand small computers, they approached Bill Gates, who, with other shareholders, owned a small software company called Microsoft, which at the time had 32 employees. Microsoft delivered an operating system called MS DOS which was used on the new IBM computer. Bill Gates was a very clever businessman, and he retained the IPR for MS DOS and was able to licence it later to many other computer manufacturers, thus eventually turning Microsoft into a more valuable corporation than IBM.
苹果二的成功说服过IBM重要进去这个新市场，虽然每个人电脑的价格比住架电脑的很小。为了完成那个设计，他们需要一个软件系统， 原因是需要制导电脑里的硅片和别的器。由于IBM的工程师不知道小电脑，他们接触了比乐给特子 （Bill Gates), 叫微软小公司的主人之一，那时候微软有了三十二工员。微软生产了一个叫MS-DOS的软件系统。所以那个新的IBM个人电脑利用这个软件。比乐给特子是一位很聪明的商人，所以他保留了MS-DOS的专利权，能以后核准向很多别电脑公司，终于微软比IBM贵多了。
The IBM PC, as it became known, was one of the most successful products in history. There are now approximately 5Bn PCs in use. One of the reasons for its success was that it attracted many software developers to produce software to be used on the machine, thus making it extremely useful in a large number of applications. Initially the software was word processors, spreadsheets and databases, but tens of thousands of applications were eventually designed for use on these machines.
A further development by Microsoft that made PCs much easier to use was Windows. A design of this type was initially included by Apple with their Macintosh machine, but Windows was a far more popular application. Yet another development came in 1995 when Microsoft introduced the Internet Explorer browser, which enabled a further major application for the PC, as an Internet terminal.
Many PC users have now graduated to using tablets, a smaller, more convenient device than the PC. A further development is the smart phone, which means that the user owns a computer that only has the size of a phone. Fifty years from a computer the size of a room to a computer in your hand!