-The period of first generation was from 1946 to 1959; was Vacuum tube based. -The computer were enormous and often took up entire rooms. -The first generation relied on machine language. -The UNIVAC and Eniac computers are examples of first-generation computing devices. -the univac was the first commercial computer delivered to a business client in 1951.SOurces -http://www.webopedia.com/DidYouKnow/Hardware_Software/2002/FiveGenerations.asp