This document provides an overview of the evolution of computers from the abacus to modern day computers. It discusses early calculating devices like the abacus, Pascal's adding machine, and Babbage's analytical engine. It then covers the development of programmable, electronic computers starting with ENIAC in the 1940s. The document also describes different generations of computers based on the underlying technology and classifications of computers based on size, speed, and purpose. Finally, it discusses the basic components of a computer system including input, output, memory, arithmetic logic unit, and control unit.

1. Presentation made by: Ms. Archika Bhatia COMPUTER SYSTEM ORGANISATION

5. Slide Rule Slide Rule 1630 based on Napier’s rules for logarithms used until 1970s

8. first stored program - metal cards first computer manufacturing still in use today! Jacquard Loom - 1801

19. Hardware refers to physical components that can be seen and touched. E.g. CPU, Memory, I/O devices. HARDWARE SOFTWARE Software is a set of programs that make the Hardware of the computer run. Program is a set of instructions.

24. SECOND GENERATION TIME PERIOD : 1950's- 1960's TECHNOLOGY USED : Transistors SIZE AND SPEED : Lesser size and increased speed LANGUAGE USED : Assembly language and languages like COBOL and FORTRAN COST : Cost decreased OTHER FEATURES : More efficient and reliable. Though the transistors still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output. EXAMPLE : UNIVAC 1108, IBM 1401, CDC 1604 UNIVAC 1108 IBM 1401 TRANSISITORS

25. THIRD GENERATION TIME PERIOD : late 1960's-1970's TECHNOLOGY USED : Integrated Circuit SIZE AND SPEED : Size Lesser and speed further increased LANGUAGE USED : Operating System was developed. COST : Cost decreased further OTHER FEATURES : Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system , which allowed the device to run many different applications at one time with a central program that monitored the memory. Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors. EXAMPLE : IBM-360 series, Honeywell Model 316, Honeywell – 6000 series, CDC – 1700. IBM 360/50

30. Sixteen racks of IBM's Blue Gene/L supercomputer can perform 70.7 trillion calculations per second, making it the fastest machine known so far.

38. Types of Software Software ( Set of programs that govern the operations of computer ) System Software ( Software that controls internal computer operations ) Application Software ( Set of programs to carry out operations for a specified application ) Operating System ( Software which acts as an interface between user and the hardware ) Language Processor ( Software which converts HLL progran into machine language ) Packages ( General utility software ) Utilities ( perform house keeping ) Customized Software ( Tailor made software according to user’s needs )

42. Generations of Computer Languages Low Level Language Fifth Generation Fourth Generation Third Generation (High Level Language) Second Generation (Assembly Language) First Generation (Machine Language)

47. FIRST GENERATION : Machine language i.e. language of 0 and 1 SECOND GENERATION : Assembly language Similar to English Uses mnemonics codes THIRD GENERATION : High Level Language Very close to English E.g. C, C++, Java, VB FOURTH GENERATION : Languages for accessing databases FIFTH GENERATION : Uses a visual or graphical development interface to create source language that is usually compiled with a 3GL or 4GL language compiler Used mainly in artificial intelligence research E.g. Prolog , OPS5 , and Mercury

48. BLOCK DIAGRAM OF A COMPUTER

49. B ASIC C OMPONENTS of C OMPUTER S YSTEMS Secondary Memory (Block Diagram)

50. Input/Output B ASIC C OMPONENTS of C OMPUTER S YSTEMS Secondary Memory

52. INPUT DEVICES SCANNER LIGHT PEN

56. Input/Output Page 29 Multimedia – relatively new term for computer input and output in the form of text, graphics, sound, still images, animations, and/or video Of interest … B ASIC C OMPONENTS of C OMPUTER S YSTEMS

57. Computer Memory B ASIC C OMPONENTS of C OMPUTER S YSTEMS Secondary Memory

60. Bits and Coding Schemes Page 32 Figure 2.4 Computer Coding Schemes . . . . . . . . . . . . . . . . . .

61. Arithmetic/Logical Unit B ASIC C OMPONENTS of C OMPUTER S YSTEMS Secondary Memory

63. Computer Files (Secondary Memory) B ASIC C OMPONENTS of C OMPUTER S YSTEMS Secondary Memory