The microprocessor ushered in the 'fourth generation' of computers. Thousands of integrated circuits were fit into a single miniscule chip using VLSI and ULSI technology. This made the computers smaller, more portable and much faster than before. In 1981, IBM introduced a computer especially designed for use at home. Apple followed with its 'Macintosh'. These small computers were very powerful and permitted linking of several machines that eventually led to networking and the internet.