1. Lesson 1

2. ssr/1.0/150708 Elements of Computer Systems 2/20 Topics to cover Charecteristics of a Computer Charecteristics of a Computer The Binary Story The Binary Story Computer System Organisation Computer System Organisation Memory Memory Types & classification of Computers Types & classification of Computers

3. ssr/1.0/150708 Elements of Computer Systems 3/20 Charecteristics of a Computer Speed Speed Process voluminous data at amazing speed Process voluminous data at amazing speed Storage Storage Important feature of Computing technology is storing the data Important feature of Computing technology is storing the data Accuracy Accuracy Accurate always Accurate always Versatility Versatility Can compute arithmetic, text & Logical operations too Can compute arithmetic, text & Logical operations too

4. ssr/1.0/150708 Elements of Computer Systems 4/20 Charecteristics of a Computer Compactness Compactness From big Machines to palmtop From big Machines to palmtop Reliability Reliability More reliable than the human brain More reliable than the human brain Repititiveness Repititiveness Performs similar iterative task without loosing speed or accuracy Performs similar iterative task without loosing speed or accuracy Diligence Diligence Does not loose concentration or get fatigued Does not loose concentration or get fatigued

5. ssr/1.0/150708 Elements of Computer Systems 5/20 The Binary Story BIT BIT BYTE BYTE WORD WORD 1 1 BIT 1 1 BIT 2 1 2 0 2 1 2 0 2 1 = 3 2 1 = 3 (3 ) 10 (11) 2 (3 ) 10 (11) 2 Each symbol of 0 or 1 is known as a BIT

6. ssr/1.0/150708 Elements of Computer Systems 6/20 B I T B I T Binary Two-State-Operation Binary Two-State-Operation A number system using the base of 2 A number system using the base of 2 Only 2 numeric symbols - 0 & 1 Only 2 numeric symbols - 0 & 1 Conversion of Decimal to Binary & Binary to decimal Conversion of Decimal to Binary & Binary to decimal

7. ssr/1.0/150708 Elements of Computer Systems 7/20 Conversion Decimal to Binary Decimal to Binary 15 = 2 15 - 1 L S D 15 = 2 15 - 1 L S D = 2 7 - 1 = 2 7 - 1 = 2 3 - 1 = 2 3 - 1 = 2 1 - 1 M S D = 2 1 - 1 M S D = 1 1 1 1 = 1 1 1 1 Binary to Decimal Binary to Decimal 1 1 1 1 = 2 3 2 2 2 1 2 0 1 1 1 1 = 2 3 2 2 2 1 2 0 8 +4 + 2 + 1 = 15 8 +4 + 2 + 1 = 15

8. ssr/1.0/150708 Elements of Computer Systems 8/20 BYTE The alphabets or numbers are represented with 8 bits or 16 bits or 32 bits and so on The alphabets or numbers are represented with 8 bits or 16 bits or 32 bits and so on A group of BITs used to represent an alphabet or a numeral or a character is called a BYTE A group of BITs used to represent an alphabet or a numeral or a character is called a BYTE Ex in an 8 bit machine 1 alphabet or numeral is represented using 8 BITS Ex in an 8 bit machine 1 alphabet or numeral is represented using 8 BITS Here 1 BYTE = 8 BITS Here 1 BYTE = 8 BITS

9. ssr/1.0/150708 Elements of Computer Systems 9/20 WORD No. of bits needed by a computer memory to store one unit of information is called a WORD. No. of bits needed by a computer memory to store one unit of information is called a WORD. 1 byte = 8 bits 1 byte = 8 bits 1 kilobyte(KB) = 1024 bytes 1 kilobyte(KB) = 1024 bytes 1 Megabyte(MB) = 1024 KB 1 Megabyte(MB) = 1024 KB 1 Gegabyte (GB) = 1024 MB 1 Gegabyte (GB) = 1024 MB

10. ssr/1.0/150708 Elements of Computer Systems 10/20 The C P U Input Store Retrive Output Storage Device Auxiliary & Backup Store Display Main Memory Control Unit Arithmetic & Logic Unit Output Central Processing Unit ( C P U ) Monitor or Display Unit Key Board Printer CD Drive

11. ssr/1.0/150708 Elements of Computer Systems 11/20 Memory ROM ROM Masked ROM Masked ROM PROM - Programmable Read only Memory PROM - Programmable Read only Memory EPROM – Erasable Programmable Read only Memory EPROM – Erasable Programmable Read only Memory UVEPROM - Ultra Violet Erasable Programmable Read only Memory UVEPROM - Ultra Violet Erasable Programmable Read only Memory EEPROM - Electrically Erasable Programmable Read only Memory EEPROM - Electrically Erasable Programmable Read only Memory

12. ssr/1.0/150708 Elements of Computer Systems 12/20 Main Memory Control Unit Arithmetic & Logic Unit Random Access Memory ( R A M ) for Read & Write Read Only Memory (R O M ) O/S Appln Prgm Exec Prgm BIOS Supervisory Memory User memory

13. ssr/1.0/150708 Elements of Computer Systems 13/20 R O M Control Unit Arithmetic & Logic Unit Main Memory Random Access Memory ( R A M ) for Read & Write (R O M ) O/S Appln Prgm Exec Prgm BIOS Supervisory Memory User memory 1. Masked ROM 2. P R O M 3. E P R O M 4. E E P R O M D A T A

14. ssr/1.0/150708 Elements of Computer Systems 14/20 4 Type of R O M Masked R O M – Masked R O M – A bit pattern is permanently recorded. A bit pattern is permanently recorded. Specialised Manufacturing Process. Specialised Manufacturing Process. Very Expensive Very Expensive P R O M - Programmable Read Only Memory P R O M - Programmable Read Only Memory Can be programmed by User Can be programmed by User Using PROM Prgm can burn the fuses according to the bit pattern - “Burning the PROM” Using PROM Prgm can burn the fuses according to the bit pattern - “Burning the PROM” E P R O M – Erasable Programmable Read Only Memory. E P R O M – Erasable Programmable Read Only Memory. Info stored is Semi-Permanent. Info stored is Semi-Permanent. Can be erased by exposing the memory to Ultra Violet Rays. Can be erased by exposing the memory to Ultra Violet Rays. Can be programmed again Can be programmed again Most commonly used Most commonly used

15. ssr/1.0/150708 Elements of Computer Systems 15/20 E E P R O M – Electricity Erasable - E E P R O M – Electricity Erasable - Programmable Read Only Memory Programmable Read Only Memory Similar to EPROM Similar to EPROM Info can be altered using electrical signals Info can be altered using electrical signals Manufacturing process is quite complex Manufacturing process is quite complex Not commonly Used Not commonly Used Very Expensive Very Expensive E A P R O M - Electricity Alterable - Programmable Read Only Memory Programmable Read Only Memory

16. ssr/1.0/150708 Elements of Computer Systems 16/20 RAM - Random Access Memory DRAM - Dynamic Random Access Memory ( uses capacitors) DRAM - Dynamic Random Access Memory ( uses capacitors) Disadvantage - discharges slowly ie memory requires refreshing Disadvantage - discharges slowly ie memory requires refreshing SRAM - Static Random Access Memory SRAM - Static Random Access Memory uses Flip-Flop Registers uses Flip-Flop Registers Faster & Cheaper so widely used Faster & Cheaper so widely used

17. ssr/1.0/150708 Elements of Computer Systems 17/20 Types of Computer AnalogDigital Hybrid Analog - Solves Problem by operating on contineous Variables. Analog - Solves Problem by operating on contineous Variables. Digital - performs arithmetic, logical & comparative functions on info in digital form Digital - performs arithmetic, logical & comparative functions on info in digital form Combines features of Analog & Digital Combines features of Analog & Digital

18. ssr/1.0/150708 Elements of Computer Systems 18/20 Grid Computer Grid Computer Super Computer Super Computer Mainframes Mainframes Mini Computer Mini Computer Microcomputer Microcomputer Terminal Embedded Computer Terminal Embedded Computer Classification of Computer

19. ssr/1.0/150708 Elements of Computer Systems 19/20

20. ssr/1.0/150708 Elements of Computer Systems 20/20