Lec 06 Computer Hardware (System Unit)

(1)

1

CS1010 Introduction to Computing

Lecture 06

Computer Hardware

(2)

(3)

WHAT IS THE SYSTEM UNIT?

• _{Box like case}_{that houses the}_electronic

(4)

Information Processing Cycle:

The task of computer, in low level, is to process given data to produce information. Computer takes data, then processes the data as per being instructed and then can either output the generated information to user or store the information to storage or can do both. The generated information can be treated as data in the next cycle. These operations are part of a process called Information Processing Cycle which is a set of steps that computer follow to receive data, process the data and then either display the output to user or store the output to storage or do both.

Four Phases of Information Processing Cycle: 1. Input:

In this phase the computer receives data from input source by user or a program. An input source by user can be an input device like keyboard, mouse, microphone etc.

2. Processing:

After receiving data, here the computer performs actions on the data like mathematical operations or logical comparisons etc. as per being instructed by user or a program.

3. Output:

After processing the data computer has generated information that now can be sent to output. Output can be sent for display in monitor, or to printer or speaker as sound etc. It is also as per required by the user or program.

4. Storage:

Again, after processing the data, computer can also store the data into an storage device for future use.

Phase output and storage, are optional. Both of them can be required and vice-versa, as the generated information can also be directly used by another processing cycle where this generated information will be treated as data to be

(5)

SYSTEM UNIT

• _{The main components of system unit are here}

under:

• _{Mother Board}

• _CPU

• _{Primary Memory}

• _{Ports & Connectors}

• _Buses

• _Storage

• _{Power Supply}

(6)

System Unit

Processor

RAM

Sound Card

Modem Video Card

NIC Card

(7)

MOTHER BOARD

• _{It is the}_{primary circuit board}_{in a computer or}

other electronic device. All the components

connected with CPU are through motherboard.

• _{Main circuit board in system unit has.}

– _{Microprocessor}_.

– _{Integrated Circuits.(control the system)}

– _{Expansion slots.(to attach other devices)}

(8)

(9)

EXPANSION SLOTS & EXPANSION CARDS

(10)

EXPANSION SLOTS & EXPANSION CARDS

(11)

RAM Slots/ROM

• _In_{RAM slots}_{we fix}_{RAM chips}_.

• _{In motherboard we also have}_{ROM chip}_,

(12)

CMOS Battery

• _{On motherboard we have a small battery}

called CMOS battery.

• _{It contains information about}_{date and time}_of

computer, when computer goes to sleep mode and shut down.

• _{When computer is}_{turned off CMOS battery}

(13)

Display Card

• _To_{display output on monitor}_{, computer must}

have graphic card or video card installed.

• _{Video card provides instructions to program}

that is running inside a computer to display on monitor.

• _{There is two types of video card i.e.}_{VGA and}

(14)

Sound Card

• _{Similarly on motherboard there is slot for}

sound card.

• _{Sound card}_{converts digital information into} analog signals and vice versa.

• _{Speakers output the voice which is sent by}

(15)

MODEM

• _{The word}_modem_{is made by combining two words}

Modulator and Demodulator.

• _Mo_{is first two letters of}_Modulator_while_dem_{is first}

three letters of Demodulator.

• _Microphone_{is like a modulator, speaker is demodulator}

both found in telephones.

• _Modem_{is used for both the purposes of input and}

output. Modulator and Demodulator both were found in

(16)

LAN Card

• _{If we want to form a}_{Local Area Network (LAN)}

then on each computer motherboard we must have installed a LAN card.

• _{LAN card is also known as}_{Network Interface}

(17)

Peripheral Devices

• _{Peripheral devices are those devices,}_{without these devices}

computer can work.

• _{These devices are}_{not necessary}_{in a computer.}

• _{Usually peripheral devices}_{enhance the functionality}_{of a}

computer.

• _{Mouse and keyboard}_{are peripheral devices.}

• _Examples:

(18)

(19)

PROCESSOR

• _{Processor is the}_{main engine}_{, which do all}_arithmetic_,

logic calculations and control function of the computer.

• _{Various processors:}

– _Intel

• _{Pentium Pro, II, III, IV, Dual-Core, Core-2, Core i3, Core i5, Core i7.} • Celeron

– _AMD

• _{Athlon, Sempron,}

– _PowerPC_{(Apple, Motorola)}

– _StrongARM_{(specially designed for PDAs)}

– _SPARC _{(for workstations designed by Sun Microsystems)}

(20)

(21)

BUSES

• _{What is a bus?}

• _{Electrical channel}_{that allow various devices} inside the computer to communicate with each other.

• _{Bus width}_{determines the number of bits}

(22)

THE BUS

• _{In any computer, you will find two}_bus_{at least:}

– _{System Bus}_{(processor communicate to input}

devices, output devices and storage)

– _{Memory Bus}_{(processor to memory}

(23)

• _{The number of}_wires_{in the}_bus_{affects the}

speed at which data can travel.

• _{Each wire can}_{transfer one bit}_{of data at a}

time, an eight-wire bus can move eight bits at a time.

• _{Newer model computers have a}_{64-bit data}

(24)

(25)

MEMORY BUS

• _{Memory Bus}_connects_{processor and RAM}_{. It is subdivided into two} types:

–_{Address Bus} –_{Data Bus}

• _{Address Bus}

The address bus is uni-directional pathway that carries addresses generated by the microprocessor to the memory.

• _{Data Bus}

• _{The data bus is}_{bi-directional}_.

• _{Data flows along the data bus from the microprocessor to memory}

during a WRITE operation.

• _{Conversely, data moves from memory to the microprocessor during}

(26)

(27)

MEMORY vs STORAGE

• _{What is Storage?}

• _The_media_{on which data, instructions and}

information are kept permanently.

• _{Storage is also called}_{Secondary Storage}_. • _{Storage is}_non-volatile_.

• _{What is Memory?}

• _The_media_{on which data and information are}

kept temporarily.

(28)

MEMORY/STORAGE

• _Memory

– _Ram_(volatile)

– _Rom_{(non volatile)}

• _Storage

– _{Punch card}

– _{Magnetic Tapes}

– _{Magnetic Disks/Hard disk} – _{Floppy Disk}

(29)

CLASSIFYING MEMORY/STORAGE

• _{Classify of memory/storage:}

– _{Electronic storage}_(RAM/ROM)

– _{Magnetic storage}_{(Hard Disk, Floppy Disk, Tape)}

– _{Optical storage (CD, DVD)}

• _{Another way of classifying is:}

– _Volatile_(RAM)

(30)

• _{Another way of classifying is Direct & Serial}

access:

– _{Direct Access}_{(RAM, Floppy Disk, Hard disk & CDs)}

– _{Serial Access}_{(Magnetic tape)}

• _{Another way of classifying is Read/Write:}

– _Read_{(CDs, Magnetic Tapes)}

(31)

(32)

ACCESS TYPES

(33)

ACCESS TIME

• _{What is Access Time?}

• _{The amount of time}

it takes the device to locate an item on a disk.

• _{Defines the speed of}

(34)

MAGNETIC TAPES

• _{A magnetically coated ribbon of plastic capable}

of storing large amount of data and information at a low cost.

• _{Sequential access}

only.

• _{Often used for}

(35)

FLOPPY DISKS

• _A_{portable inexpensive storage}_medium.

• _{Consist of a thin, circular,}_{flexible plastic disk}

with a magnetic coating.

• _{Enclosed in a} square-shaped plastic shell.

• _{Standard disk is 3.5”}

(36)

HARD DISKS (1/4)

• _{Consists of several inflexible, circular platters}

that store data electronically.

• _{Also known as}

(37)

HARD DISKS (2/4)

• _{What is a removable hard disk?}

(38)

HARD DISKS (3/4)

• _{What is a RAID?}

• _{Redundant Array of Independent Disks.}

• _{A type of hard disk system that connects}

several smaller disks into a single unit that acts like a single large hard disk.

• _{More reliable than a}

(39)

HARD DISKS (4/4)

• _{What is an Internet Hard Drive?} • _A_{service on the web}

that provides storage to computer users.

• _{Sometimes called}

online storage.

(40)

• _{Advantage of Internet Hard Drive:}

• _{Large Audio, Video and Graphic files can be}

stored to an internet hard drive.

• _{Files can be accessed from any computer or}

device that has internet access.

• _{Others can be authorized to access data from}

(41)

COMPACT DISC (CD)

• _{A flat, round,}_{portable optical storage}

medium.

• _CD:_650MB

• _DVD: _{4.7GB – 17GB}

(42)

(43)

WHAT IS A PORT?

• _{A port is a connection point, a point through} which you connect any input or output device or external devices to the system unit.

• _{Ports are used to connect external devices with}

computer i.e. mouse, keyboard, modem etc…

• _Example:

(44)

(45)

TYPES OF PORTS

• _{Following are the famous ports:}

– _{Parallel Port}

– _{Serial Port}

– _SCSI

– _{USB Port}

(46)

PARALLEL PORT

• _{Exclusively used for}_{connecting a Printers}_and Scanners .

• _{25-pin Connector}_.

• _{Support transmission of}_{multiple bits}_{at the same}

(47)

SERIAL PORT

• _{1 bit}_{of information is transferred at a time.}

• _{In past}_{digital camera’s}_{were connected,}_{Bar code,}

(48)

SCSI (Small Computer System Interface)

• _{Faster than}_serial_and_{parallel port}_.

• _{Hard disk and}_{network adaptor}_{to be attached to a}

(49)

USB PORT

• _Bandwidth_{of 12 Mbit/sec}

• _{For peripherals such as keyboard,}_mouse_,_scanner_,

printer.

• _{A USB port can connect}

(50)

FIREWIRE PORT

• _{Can connect to}_{digital cameras}_{, camcorders or external}

hard drives.

• _{KB-AT Port}

(51)

(52)

Power Supply

• _{Power Supply provides electricity to entire}

computer.

• _{A simple power supply takes 220 Walt (AC) to}