Second Generation (1956 - 1963): Transistors

Second generation computers used transistors, which were superior to vacuum tubes. A transistor is made up of semiconductor material such as germanium and silicon. It usually has three leads and performs electrical functions such as voltage, current or power amplification with low power requirements. Since transistor is a small device, the physical size of computers was greatly reduced. Computers became smaller, faster, cheaper, energy efficient and more reliable than their predecessors. In second generation computers, magnetic cores were used as primary memory and magnetic disks as secondary storage devices. However, they still relied on punched cards for input and printouts for output.One of the major developments of this generation includes the progress from machine language to assembly language. Assembly language uses mnemonics (abbreviations) for instructions rather than numbers, for example, ADD for addition and MULT for multiplication. As a result, programming became less cumbersome. These computers were more reliable and less prone to hardware failure, hence, they required less frequent maintenance. Moreover, these were more portable and generated less Fundamentals of Computers I-7amount of heat. However, the second generation computers still required air conditioning and manual assembly of individual components into a functioning unit. Some examples of second generation computers are PDP-8, IBM 1401 and IBM 7090.