Intro to Computer Systems

7/31/2019 Intro to Computer Systems

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COMPUTER ARCHITECTURE

JC Harambearachchi


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Recommended Text

1 Computer Organization and Architecture

by William Stallings

2 Structured Computer Organisation

Andrew S. Tanenbaum


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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 calledsoftware.


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fig computer

Input process output


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Computer System

Hardware

Software

OSApplication SW

Live ware


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1 input operation

2 processing operation-cpu

3 storage operation-primary / secondry

4 output operation

5 Communication operations

What are basic operations of a Computer?


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Components of a Computer System

Computer hardware provides the physical mechanisms toprocess, 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.


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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 ?


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Keyboard pic

mouse

Input Hardware


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cpu pic

Memory chips pic

Motherboard pic

Process and memory Hardware


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Hard drive

Floppy

Cd/dvd

Storage Hardware


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Monitor

Speaker

Printer

Video card

Sound card

output Hardware


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Modems pic

Communication Hardware


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System Software

Windows pic

Linux pic Device drivers

Application softwaere

Word Exel

ppt

Software


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Entertainment

PERSONAL

Education

Productivty

Specality

Word processing pic Spread sheets

Database

Ppt

Quicken microsoft money

Application Software types


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Drawing

Web page desin

cad

Application Software types


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Block Diagram of a Computer

Main Memory

IOD IOD IOD

IO Modules

CPU


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Computer Hardware


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1 Hardware- the CPU

CPU performs actual processing of data, according to

instructions from programs.

Data and programs are stored in primary and secondarymemory, 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.


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Central Processing Unit ( CPU)

1. Acting as the brainof the computer

2. Currently the Intel-Pentium microprocessor is the

most common CPU though there are many types


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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 ofinstructions

Registers - small high speed storage areas


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Components of a computer system


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Computer Hardware


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2 Hardware - memory

Memory - Purpose of memory is data storage. Two majortypes of memory :

Primary memory - to hold data and instructions duringprocessing

eg RAM. Relatively limited capacity and volatile

Secondary memory - to provide permanent long termstorage

eg hard disk. High capacity and non-volatile


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Main Memory (RAM)

1. Different from disk storage

2. used to temporarily store Data

3. in modern computers memory is 512 MB.


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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.


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0

1

2

3

4

5

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 are16, 32 and 64 bits.


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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 = 210

3. 1MB = 1024 KB= 220

4. 1GB = 1024 MB = 230

5. 1TB = 1024 GB = 240


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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.

CDs and DVDs store data as pits or surface marks

detectable by laser light.


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3 HardwareI/O

Input Devices collect & translate raw data into form useableby 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.


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HardwareI/O Peripherals

1 Input Devices Mouse

Keyboard

2 Output Devices Monitor (VDU)

Printer

3 Secondary Storage Devices Hard Disk

CD / DVD / Floppy


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I/O Hardware


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4 Hardware - I/O Modules

Interface between System Bus and other Peripherals

example

Sound cards

Video cards

Network cards

PCI cards


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5 Hardware - System Bus

series of electronic path ways and connecting other

components of the computer.


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Computer

MainMemory

Input

Output

Systems

Interconnection

Peripherals

Communication

lines

Central

Processing

Unit

Computer

Structure - Top Level


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Structure - The CPU

ComputerArithmetic

and

Login Unit

Control

Unit

Internal CPU

Interconnection

Registers

CPU

I/O

Memory

System

Bus

CPU


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Types of computers

Personal Computer

Microprocessor

Mini computer

Main frame

Super computer

T f t


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Types of computers

supercomputer: An extremely fast computer that can perform hundreds of millionsof instructions per second.

IBM ASCI pic mainframe: A powerful multi-user computer capable of supporting many hundreds

or thousands of users simultaneously. Banks air lines vp2400 pic

Work stations minicomputer: A multi-user computer capable of supporting from10 to hundreds of users simultaneously.

Designing , movies , Sun ws pic Microcomputers personal computer: A small, single-user computer based on a

microprocessor. Desktop PC pic

Notebook pc (laptop)

PDAs palmtops

Microcontrollers embeded computers
http://www.webopedia.com/TERM/C/supercomputer.htmlhttp://www.webopedia.com/TERM/C/mainframe.htmlhttp://www.webopedia.com/TERM/C/minicomputer.htmlhttp://www.webopedia.com/TERM/C/multi_user.htmlhttp://www.webopedia.com/TERM/C/personal_computer.htmlhttp://www.webopedia.com/TERM/C/user.htmlhttp://www.webopedia.com/TERM/C/microprocessor.htmlhttp://www.webopedia.com/TERM/C/microprocessor.htmlhttp://www.webopedia.com/TERM/C/user.htmlhttp://www.webopedia.com/TERM/C/personal_computer.htmlhttp://www.webopedia.com/TERM/C/multi_user.htmlhttp://www.webopedia.com/TERM/C/multi_user.htmlhttp://www.webopedia.com/TERM/C/multi_user.htmlhttp://www.webopedia.com/TERM/C/minicomputer.htmlhttp://www.webopedia.com/TERM/C/mainframe.htmlhttp://www.webopedia.com/TERM/C/supercomputer.html


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Server and client


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What are Computer Ports ?

Connection point

examples1. Serial port (Com)

2. Parallel Port

3. USB port4. Ethernet Port


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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 communicationsnetwork is created


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1 Data processing

2 Data storage3 Data movement

4 Control

What are Major functions of a Computer?


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Functional view

Data

Movement

Apparatus

ControlMechanism

Data

Storage

Facility

Data

Processing

Facility


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Operations (1)

Data movement

e.g. keyboard to screen

Data

Movement

Apparatus

ControlMechanism

Data

Storage

Facility

Data

Processing

Facility


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Operations (2)

Storage

e.g. Internet download to disk

Data

Movement

Apparatus

ControlMechanism

Data

Storage

Facility

Data

Processing

Facility


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Operation (3)

Processing from/to storage

e.g. updating bank statement

Data

Movement

Apparatus

ControlMechanism

Data

Storage

Facility

Data

Processing

Facility


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Operation (4)

Processing from storage to I/O

e.g. printing a bank statement

Data

Movement

Apparatus

ControlMechanism

Data

Storage

Facility

Data

Processing

Facility

Documents

Intro to Computer Systems