The Personal Computer
Personal computers are now a very common item in many houses yet in 1955, there were only 250 computers in use throughout the world. In 1980, more than one million personal computers had been sold and by the mid-1980’s, this figure had risen to 30 million. How did this come about?
A computer in 1955 was very large and could not have fitted into a normal room in a normal sized house. They frequently burned out and had a tendency to attract moths into the system which short-circuited them. (Getting a computer ‘bug’ now refers back to the time when moths were a problem to the early computers).
By the mid-1960’s, the microchip was replacing the transistor. A microchip could have several transistors on it. But being smaller, it lead again to a decrease in the size of computers. By 1965, there were 20,000 computers in the world. The most famous was the IBM System/360.
The microchip also lead to computers being made that were small enough to get into the average sized room in a house. By 1970, one microchip could contain 1000 transistors on it. In 1970, a home personal computer would have cost nearly £70,000 in today’s money.
In 1971, the microprocessor went on sale. Developed by Ted Hoff of Intel, the Intel 4004 was to revolutionise home computing. The 4004 cost just over £3000 in today’s money but by 1972, Intel had produced the 8008 which was far more powerful that the 4004 but cost a tenth of the price of the 4004. Microprocessors had a multitude of uses but they could be used at the heart of true personal computers.
In the early 1970’s personal computers were used only by hobbyists. The first ‘hobby’ personal computer was the Altair 8800 which cost just under £900 in today’s money. It had the same power as a computer of the 1950’s that cost $1 million.
In 1975, Apple Computers was founded by Steve Jobs and Steve Wozniac. Apple created the “home/personal computer” that could be used by anybody. The computer – Apple II – was launched in 1977 and was an immediate success. The personal computer was sealed in a neat plastic case, it had a keyboard, video unit and used removable floppy discs. Above all, it only cost £2400 in today’s money. The success of Apple II established Apple Computers as the main player in the field of personal computers. By 1980, there were 1 million personal computers in the world.
The personal computer moved into the world of business when Dan Bricklin created a spreadsheet program. His program – called VisiCalc – was designed for the Apple II. It went on sale in 1979 and within 4 years it had sold 700,000 copies at $250 a time.