The Third Generation Computers

The third generation computers replaced transistors with ‘Integrated Circuits’ known popularly as chips. The ‘Integrated Circuit’ or I.C. was inverted by Jack Kilby at Texas Instruments in 1958.
An I.C. is wafer thin slice of extremely purified silicon crystals. A single I.C. has many transis-j ; tors, resistors and capacitors along with the associated circuitry encapsulated in a small pack-  age with many leads.
From small scale integrated (SSI) circuits which had about 10 transistors per chip, technology developed to medium scale integrated, (MSI) circuits with 100 transistors per chip. The size of main memories reached about 4 megabytes. Magnetic disk technology also improved and it became feasible to have drive having capacity upto 100 MBs. The CPUs because much more powerful with the capacity of carrying out 1 million instructions per second (MIPS).
The third generation computers using integrated circuits proved to be highly reliable, relatively inexpensive, and faster. Less human labour was required at assembly stage. Examples of some mainframe computers developed during this generation are : IBM-360 series, ICL-1900 series, IBM-370/168, ICL-2900, Honeywell Model 316, Honeywell-6000 series. Some mini computers developed during this phase are : ICL-2903 manufactured by International Computers Limited, CDC-1700 manufactured by Control Data Corporation and PDP-11/45 (Personal Data Processor -11/45)
Computers these days found place in other areas also like education, survey, small businesses, estimation, analysis etc. along with their previous usage areas i.e. scientific and engineering.