1.History.pptx

Lesson 01 - Generations of Computers Lecturer: Ms. Thilini Hettiarachchi 1 08/15/2024  Outline Generations of Computers Von Neumann Architecture The main components of a computer CPU, its elements a...

Lesson 01 - Generations of Computers Lecturer: Ms. Thilini Hettiarachchi 1 08/15/2024  Outline Generations of Computers Von Neumann Architecture The main components of a computer CPU, its elements and functioning Bus Architecture I/O Modules 7  Generations of the Computer 1st Generation computers(1944-1955) 2nd Generation computers (1955-1964) 3rd Generation computers (1964-1971) 4th Generation Computers (1971- ) 8  1st Generation Computers Main characteristics of this generation  This generation computers used Thermion valves  These computers large in size and very heavy in weight  Power consumption was very high  Writing program on them was difficult or quite slow 9  1st Generation Computers(contd.) Electronic Numerical Integrator and Calculator (ENIAC)  1946 : First electronic general purpose calculator ,ENIAC (Electronic Numerical Integrator and Calculator ) built in U.S, weighs 33 tons consumes 150 kw and averages 5000 operations per second 10  Hard Wired Programming Early computers were programmed, using large number of switches in the console panel and plugging/unplugging cables It is called hardwired programming Two women working with ENIAC computer United States Army Photo. 11  Invention of Transistor  1947 : Transistor, essential storage device for computers invented at Bell Labs by American engineers William Shockley, John Bardeen, and Walter Bartain.  Transistors were much smaller, more rugged, cheaper to make and far more reliable than valves. 12  John Von Neumann It was required re-wire and re-design the machine to run a different programme. It was a manual and very tedious task Von Neumann proposed that programmes and data can be stored in a memory device and instead of rewiring the machine we can change the programme easily. 13  Von Neumann Architecture Important Components 14  Von Neumann Architecture  The use of the binary number system  A single sequentially addressed memory  A separate arithmetic/logic unit for performing arithmetic and logical computations  The stored program concept in which both the programs and its data are stored in memory.  A controller that fetches instructions from memory and executes them. 15  Hard Wired Programming…… 1948 :First stored program computer, Manchester Mark 1 , built in UK. Using valves It can perform about 5000 operations per second and has the first RAM. It fills a room the size of a small office. The Manchester Mark 1 computer Courtesy of the School of Computer Science. The University of Manchester. 16  2nd Generation Computers (1955-1964)  Used transistors instead of the bulky electric tubes.  Comparatively higher operating speed.  Size and the weight of the computers got reduced considerably  Manufacturing cost also very low  The concept of Central Processing Unit (CPU), memory, programming language and input and output unites were developed.  Another major feature was the use of high-level programming languages. These revolutionised the development of software for computers. The computer industry experienced explosive growth 17  2nd Generation Computers IMB 1620 IMB 1401 18  3rd Generation Computers(1964-1971) Used Integrated Circuits (ICs) for the machines (A single IC has many transistors, registers and capacitors built on a single thing slice of silicon.) The size of the computer got further reduced High Level Languages were developed in this generation Large IC companies were started. (INTEL started in 1968, AMD started in 1969) The computers of this generations were low cost, large memory and processing speed was very high. 190  3rd Generation (contd.) Substantial operating systems were developed to manage and share the computing resources and time-sharing operating systems were developed. These greatly improved the efficiency of computers. Computers had by now pervaded most areas of business and administration 20  3rd Generation Computers IBM System/360 IBM System/370 21  3rd Generation Computers 1964: BASIC (Beginners All-Purpose Symbolic Instruction Code) was created by professors at Dartmouth College ,US. BASIC later became popular among personal computers. 1965: First commercially successful microcomputer, DEC PDP-8 was produced in US. 22  4th Generation Computers (1971-) Personal computers were developed and IBM launched the Power PC and Pentium introduced the 8088 and 8086 microprocessors. (Most of the computers at present are belong to this generation) It uses large scale Integrated Circuits (LSIC) built on a single silicon chip called microprocessors. Later very large scale Integrated Circuits (VLSIC) replaced LSICs. Memory chips are in megabit range On the software side, more powerful operating systems are available such as Unix. Applications software has become cheaper and easier to use. Software development techniques have vastly improved. Fourth generation languages 4GLs make the development process much easier and faster. Software is often developed as application packages 23  Summary of Computer Generation 24