The Four Generations of Computers

By Roisin Shanks

Genration One 1945 - 1955

The first generation of computers was very large computers made up of vacuum tubes and often programmed using wired plugboards. They were also often programmed with machine language. They were mostly used for numerical calculations such as mathematical tables.


Generation Two 1955 - 1965

The second generation had mainframes made up of transistors. At first punch cards were used to provide input, then tapes were used. It used Assemblers for program writing. Simple batch processing was used with input files, programs and output on tape smaller computers was used to read programs and data on punch cards on to input tapes and for offline printing. Used mainly for scientific and engineering applications.


Generation Three 1965 - 1980

The third generation had capable of running several jobs at the same time. Fixed disks were used and new jobs on cards to be executed could be read on to the disk while executing other jobs. Though the first models used multiprogrammed batch processing, to cater to increased response time, timesharing was introduced later. Complex OSs were used. Used for various applications including scientific and business applications.


Generation Four 1980 - Today

The forth and final generation included mainframes, Minicomputers, Workstations, Personal Computers, Desktop and portable. Network operating systems that facilitate file sharing, remote logging. Distributed OSs that make use of multiple machines and processors to run applications. Virtual Machines and Network Computers. This is the current generation and it very advanced.