1. COMPUTER ARCHITECTURE

2. Recommended Text 1Computer Organization and Architecture by William Stallings 2Structured Computer Organisation Andrew S. Tanenbaum

3. A Computer is A programmable machine. It can execute or run a pre- recorded list of instructions which follow certain rules (a program). Modern computers are electronic and digital. The actual machinery -- wires, transistors, and circuits -- is called hardware; the instructions and data are called software.

4. Computer System Hardware Software –OS –Application SW Live ware

5. Components of a Computer System Computer hardware provides the physical mechanisms to process, store, and input /output data. Includes CPU, memory, I/O devices Software provides instructions to tell the hardware what tasks to perform. It includes system (eg Windows XP) and application (eg Excel) software Data in the computer may be representing numbers, characters, graphics etc but is always kept in a form that the hardware and software can manipulate.

6. central processing unit primary memory secondary storage input devices output devices communications devices I/O cards System Bus What are the major Hardware components of the computer ?

8. Block Diagram of a Computer Main Memory IOD IO Modules CPU

9. Computer Hardware

10. 1Hardware- the CPU CPU performs actual processing of data, according to instructions from programs. Data and programs are stored in primary and secondary memory, and moved to and from CPU as required. Signals representing data and instructions travel between system components along electronic pathways, called buses. Capacity of bus is critical to system performance.

11. Central Processing Unit ( CPU) 1.Acting as the brain of the computer’ 2.Currently the Intel-Pentium microprocessor is the most common CPU though there are many types

12. Hardware - The Processor The CPU is a general purpose processor that performs data manipulation and/or transformation functions including computations, comparisons and data movement. The CPU consists of 3 main parts: –ALU - where arithmetic and logical operations performed –Control Unit - controls data movement and execution of instructions –Registers - small high speed storage areas

13. Components of a computer system

14. Computer Hardware

15. 2Hardware - memory Memory - Purpose of memory is data storage. Two major types of memory : Primary memory - to hold data and instructions during processing –eg RAM. Relatively limited capacity and volatile Secondary memory - to provide permanent long term storage –eg hard disk. High capacity and non-volatile

16. Main Memory (RAM) 1.Different from disk storage 2.used to temporarily store Data 3.in modern computers memory is 512 MB.

17. Hardware- memory Digital computers deal with data in binary form - all data is represented using just two digits - 1 or 0. Letters and other symbols are assigned unique binary codes. Primary memory consists of a set of locations defined by sequentially numbered addresses. Each location contains a binary number that can be interpreted as data or an instruction.

18. 012345012345 1 0 0 1 0 0 0 1 1 1 0 1 0 0 1 1 0 1 0 0 0 0 0 0 1 0 1 0 0 1 1 1 1 1 1 0 1 0 1 0 1 1 0 0 1 0 1 0 Memory locations, using an 8 bit word  Memory locations are called words. Words are 8 bits (one byte) in size, or a multiple of 8. Common word sizes are 16, 32 and 64 bits.

19. Hardware - memory Memory is commonly measured in multiples of bits and bytes. 1 bit = 1 binary digit (0 or 1). 1. 1 byte = 8 bits 2.1KB = 1024 bytes = 2 10 3.1MB = 1024 KB= 2 20 4.1GB = 1024 MB = 2 30 5.1TB = 1024 GB = 2 40

20. Hardware - memory Secondary storage consists of non-volatile high-capacity devices to store programs and data not currently required by CPU. Hard and floppy disks, and tapes store data as magnetized spots. CD’s and DVD’s store data as pits or surface marks detectable by laser light.

21. 3Hardware – I/O Input Devices collect & translate raw data into form useable by computer. e.g keyboard accepts letters and numbers and converts them to a binary code such as Unicode. Output devices produce results in useable form for user (or another device). e.g. monitor converts binary codes to characters and images, whilst modem converts digital data to analog form for transmission over telephone lines.

22. Hardware – I/O Peripherals 1Input Devices Mouse Keyboard 2Output Devices Monitor (VDU) Printer 3Secondary Storage Devices Hard Disk CD / DVD / Floppy

23. I/O Hardware

24. 4Hardware - I/O Modules Interface between System Bus and other Peripherals example –Sound cards –Video cards –Network cards –PCI cards

25. 5Hardware - System Bus series of electronic path ways and connecting other components of the computer.

26. Computer Main Memory Input Output Systems Interconnection Peripherals Communication lines Central Processing Unit Computer Structure - Top Level

27. Structure - The CPU Computer Arithmetic and Login Unit Control Unit Internal CPU Interconnection Registers CPU I/O Memory System Bus CPU

28. What are Computer Ports ? Connection point examples 1.Serial port (Com) 2.Parallel Port 3.USB port 4.Ethernet Port

29. Basic concepts - communication Most modern computers no longer operate in isolation - they connect to other computers via modem or a network. To enable this communication, specialized hardware and software must be added to computers. In combination with other devices such as telephones, cabling, satellites, microwaves etc., a communications network is created

30. Types of computers Personal Computer –Microprocessor Mini computer Main frame Super computer

31. Types of computers personal computer : A small, single-user computer based on a microprocessor. In addition to the microprocessor, a personal computer has a keyboard for entering data, a monitor for displaying information, and a storage device for saving data.personal computerusermicroprocessor monitorstorage device saving minicomputer : A multi-user computer capable of supporting from 10 to hundreds of users simultaneously.minicomputermulti-user mainframe : A powerful multi-user computer capable of supporting many hundreds or thousands of users simultaneously.mainframe supercomputer : An extremely fast computer that can perform hundreds of millions of instructions per second.supercomputer

32. 1Data processing 2Data storage 3Data movement 4Control What are Major functions of a Computer ?

33. Functional view Data Movement Apparatus Control Mechanism Data Storage Facility Data Processing Facility

34. Operations (1) Data movement –e.g. keyboard to screen Data Movement Apparatus Control Mechanism Data Storage Facility Data Processing Facility

35. Operations (2) Storage –e.g. Internet download to disk Data Movement Apparatus Control Mechanism Data Storage Facility Data Processing Facility

36. Operation (3) Processing from/to storage –e.g. updating bank statement Data Movement Apparatus Control Mechanism Data Storage Facility Data Processing Facility

37. Operation (4) Processing from storage to I/O –e.g. printing a bank statement Data Movement Apparatus Control Mechanism Data Storage Facility Data Processing Facility