The Micral N was the earliest microcomputer, was sold in 1972 ready to use. Other microcomputers of the time were available in kit form. The Commodore PET was introduced in 1977, followed by the Apple II – a complete unit, where the Apple I was only a circuit board. Successive models sold in increasing numbers, with the Commodore 64 selling 17 million units. Early microcomputers were developed either for home use or, with more features, for office and small businesses. The IBM-PC brought the two types of machines together and set the direction for what we know now.