Macquarie Fields College of TAFE

Macquarie Fields College of TAFE

Version 2 – 13 March 20001 - HARDWARE

1

Hardware Basics Modules

• 3650A Connect Hardware Peripherals• 3650B Install Software Applications• 3650C Maintain System Integrity• 3650F Apply Occupational Health and

safety• 3650G Operate Computer Hardware• 3650J Maintain equipment and

consumables


Systems (some examples)

• Sound

• Transport

• Water

• Communications

• Political

• Government

• Computer System


Computer System

• Input• Processing • Storage

• Output• Control


OUTPUTINPUT PROCESSING

CONTROL

STORAGE

Computer Systems

• Two Basic Areas:

• HardwareHardware

• SoftwareSoftware


What is Hardware?


Hardware

• Input Devices• CPU (Central processing unit)• Output Devices• Memory or Storage (internal and

external)

Collectively these describe the procedures Collectively these describe the procedures known as the Information Processing known as the Information Processing

CycleCycle


Information Processing Cycle


OUTPUTINPUT PROCESSING

CONTROL

STORAGE

Input Devices

• Keyboard

• Mouse/Tracking ball/Pen etc

• Touch Screen

• Pressure Pad

• Scanner


Input Devices – What they are

• Keyboard

• Mouse/Tracking ball/Pen etc

• Touch Screen

• Pressure Pad

• Scanner


Keyboard

The input device from which you type information into the computer.

Keyboards generally have alphanumeric keys, function keys, special keys, and numeric keypad.


Mouse

A mouse is a helpful tool when designing columns, boxes, and other parts of the document. It

is also helpful when manipulating images


Tracker Ball

Also known as trackballs. This is a device where spinning a ball moves

the cursor on the screen.


Touch Screen

A screen sensitive to the finger touch so that the user’s finger can select

menu commands or move the cursor.


Pressure Pad

A device with pre-determined co-ordinates on a pad that moves the

cursor in the direction that the pressure is applied.


Scanner

A scanner allows you to read images like line art, photographs, and

signatures into the computer so that they can be combined with text in a

document.


Central Processing Unit (CPU)


Central Processing Unit (CPU)

• What history do you know about the CPU?

• What types of CPU’s have been released?

• What are the functions of the CPU?


Central Processing Unit (CPU)The History

• Early personal computers where known as XTs.

• XT computers used the 8086 & 8088 processor.

• These processors were 8 bit processors and processed 8 bits on an 8 bit bus.



• Next came the AT computer.

• The ATs were known as the 286 as they used the 80286 processor

• Both XT and AT computers were capable of only running one application at a time



• The next generation the 386 was an enhanced 286 but with distinct advantages.

• This was the first processor to be capable of running multiple programs at once.



• The next Generations included:

• 80486 (486)

• 80586 (Pentium)

• Pentium II

• Today’s Pentium III



There are now three main competitors in today’s microprocessor market:

•INTEL

•AMD (Advanced Micro Devices)

•IBM (International Business Machines )


Microprocessor – How it works


Prefetch Unit BUS Interface

Decode Unit

Paging

SegmentRAM

Math LogicUnit

RegistersProtect Test

UnitControl Unit

Execution Unit

Arithmetic LogicUnit

Central Processing Unit Prefetch Unit

The Prefetch Unit decides when to order data and instructions from the Instruction

Cache or the computer’s main memory based on commands or the task at hand. When the instructions come in the most important task for the Prefetch Unit is to be sure all the instructions are lined up correctly to send off to the Decode Unit.





Decode Unit

Paging

SegmentRAM

Math LogicUnit


UnitControl Unit

Execution Unit


Central Processing Unit Bus I/O (input/output)

The Bus Unit is the place where instructions flow in and out of the

microprocessor from the computer’s main memory





Decode Unit

Paging

SegmentRAM

Math LogicUnit


UnitControl Unit

Execution Unit


Central Processing Unit Decode Unit

The Decode Unit does just that – it decodes or translates complex

machine language instructions into a simple format understood by the

Arithmetic Logic Unit (ALU) and the Registers. This makes processing

more efficient.





Decode Unit

Paging

SegmentRAM

Math LogicUnit


UnitControl Unit

Execution Unit


Central Processing Unit Control Unit

The control unit is one of the most important parts of the microprocessor

because it is in charge of the entire process. Based on instructions from

the Decode Unit, it creates control signals that tell the Arithmetic Logic Unit (ALU) and the Registers how to

operate, what to operate on, and what to do with the result.





Decode Unit

Paging

SegmentRAM

Math LogicUnit


UnitControl Unit

Execution Unit


Central Processing Unit Protection Unit

The Protection Unit verifies that the Control Unit can access the address of the first number stored in RAM. It then

forwards this number to the paging and segment units where the virtual address is translated into a ‘physical address’ for the use of the Bus I/O.





Decode Unit

Paging

SegmentRAM

Math LogicUnit


UnitControl Unit

Execution Unit


Central Processing Unit Arithmetic Logic Unit (ALU)

The ALU is the last stage of processing in the chip. The ALU is the

smart part of the chip that performs commands like adding, subtracting,

multiplying and dividing.





Decode Unit

Paging

SegmentRAM



UnitControl Unit

Execution Unit

Central Processing Unit Data Cache

The Data Cache works very closely with the “processing partners,” the

ALU & Registers, and the Decode Unit. This is where specially labeled data from the Decode Unit are stored for later use by the ALU and where final

results are prepared for distribution to different parts of the computer.


CPUs - microprocessors

• One Million or more Transistors

• Two Main types of Architecture

–Complex Instruction Set Computer (CISC)• One instruction then executes it

–Reduced Instruction Set Computer (RISC)• Combines simple instructions and executes

• More speed and power


• Speed is measured by number of times a second it moves data in and out of the (CPU) processor

• Clock speed

• Consists of millions of transistors

CPUs - microprocessor


• Transistors are .35 microns apart

• One Micron is 1/100th diameter of a human hair

• Reducing distance = more speed

CPUs - microprocessor


Output Devices

• Monitor– Screen/VDU/Display Screen

• Printer

• Modem (also an input device)

• Electronic Projector


Output Devices – What they are

• Monitor– Screen/VDU/Display Screen

• Printer

• Modem (also an input device)

• Electronic Projector


Monitor


The computer’s screen. The screen

gives you instant feedback by

displaying whatever input you have

entered.

Printer


The device that prints out a

document. Popular printers include

laser printers, dot-matrix printers, and

ink-jet printers.

Modem• Modem stands for: Modulator/Demodulator

• Converts signals from one form to another form compatible with another kind of equipment

• Widely used in data communications


Printer

Sydney Melbourne

Microcomputer Modem Modem

Telephone Line

Modem


1 1 1

0 0

1 1 1

0 0

Modem

Any of three techniques may be used by a modem to modulate digital data for transmission

• Amplitude Modulation

• Frequency Modulation

• Phase Modulation


Modem

• Amplitude ModulationThe modulation of a wave by variation of its amplitude. Uses the maximum modulation of a wave

• Frequency ModulationThe modulation of a radio wave by variation of it’s frequency

• Phase ModulationThe relative position of one complete cycle of the wave is reversed to provide the alternative wave


Modem

There are three types of modems:

• The Acoustic CouplerA box with two rubber cups into which a telephone handset is placed.

• The Internal Direct Connect ModemTransmits its signals directly through the channel


Modem

• External Direct Connect ModemIs the same as the Internal version, but all circuitry is housed in a separate box equipped with a telephone jack and a lead to connect it to the computer


Electronic Projector

Device that is used to project this program and file onto the wall or

screen.


Memory Primary Memory (storage)

• Temporary Storage known as RAM (Random Access Memory).

• The computer uses RAM to temporarily hold programs and data.


Memory Primary Memory (storage)

• RAM is Volatile. This means that it’s contents are lost when power to the computer is turned off.

• The more RAM you have, the faster your computer will run.


MemoryPrimary (RAM)

• The computer uses and manages RAM for:

1. Operating System Software - Program storage area which holds the step-by-step processing instructions

2. Data being processed by application - Wording storage area in which intermediate results are held during processingContinued


MemoryPrimary (RAM)

3. Working storage/temp for processing – Input storage area in which data is held temporarily until processing takes place

4. Buffering of input/output – Where finished results are kept before being released to the screen, printer or secondary storage device


MemorySecondary (storage)

• Permanent– Non-volatile– Slow

Types of Permanent storage are:

• Hard Disk Drive (HDD)

• Floppy Disks and Zip Drives

• RW–CD ROM

• DVD ROM


Memory

• Tape Drives

• Zip Drives

• ROM (Read only memory)

• Silicon Chips


Hard Disk Drives

• Unlike a floppy disk, a hard disk is made of aluminium or glass which has a thin layer of magnetic material.

• The internal disk of a hard drive is called a “platter”. This is spun from anywhere between 1,200 rpm (revolutions per minute) up to 36,000 rpm. Usually the faster the disk spins, the faster data can be retrieved.


Hard Disk Drives

• Hard disk sizes – like speeds – may vary, however the physical size of the drive and platter will not change. The storage capacity may increase due to the development of multiple platters.


Hard Disk Drives - Storage

• For information to be stored on a hard disk, the drive must first be formatted. This is the process of arranging the magnetic surface of the disk into tracks and sectors


Hard Disk Drives - Diagram


Sector

Tracks

Platter

Swing arm

Spindle

Magnetic head

Hard Disk Drives – Sectors and Tracks

Sectors and tracks are used because they create a layout of co-ordinates similar to that of a street directory.

To retrieve data the computer tells the hard drives circuitry to move the swing arm thus moving the magnetic head over the area of the drive in which the required data is stored.


Floppy Disks

• Floppy disks are 3½” disks incased in a hard cover.

• The term Floppy comes from the earlier versions of 8” and 5¼” disks that were incased in a flexible plastic cover.

• A floppy disk is commonly used in both the home and office as secondary media


5¼” Diskette

Floppy Disks

• Floppy disks are portable allowing you to save up to 1.4 Mb of data and transferring this data to another machine.

• Floppy disks are mainly used for:• Transportation• Archiving• Installation of small programs


Zip Disks

• Zip disks look like a 3½” floppy disk but are much thicker

• They hold up to 100 Mb of data

• Zip drives are usually external drives, allowing more freedom to transport from one location to another


Compact Disc

• CD-ROM is underlied on the optical technology

• In the early 1980s, Philips and Sony jointed their efforts to develop the compact disc, and the first disc was released in 1983


CD-ROM

The disc has three layers:

• The bottom layer is aluminium which is used as a reflective layer.

• The middle layer is polycarbonate substrate which is used to memorise digital information

• The top is the protective lacquer surface


CD-ROM – Read and Write

• Under a CD writer the high power laser beam can blast the polycarbonate substrate and produce a long hole or short hole.

• Under a CD reader, when a low power laser beam scans the hole and is reflected by the aluminium layer, the reflection is detected by a photodetector and then converted to the signals as ‘1’ or ‘0’ in digital form.


CD-ROM - Storage

Every hole on the CD represents a bit. On a typical disc, 4,800 million bits can be stamped to store 600 million bytes or characters of data which is approximately equivalent to 1,000 textbooks


CD-ROM - Usage

CD-ROMs are widely used for:

• Extensive databases

• Resources

• Encyclopaedias

• Distribution of sounds, images and multimedia systems

• High graphic games


CD-ROM – Transfer Rates

The table shows the rapid development of CD-ROM drives


TIME 1990 1993 1995 1999

SPEED 1x 2x 4x 50x

INFORMATION TRANSFER RATE (KB/SEC)

150 300 600 6900

ACCESS TIME

(MILLISECOND)1000 400 250

DVD ROM

• DVD (Digital Video/versatile Disc)• Storage capacity varies; it can either be

4.7Gb, 9.0Gb, 13Gb and 17Gb. The discs can be double layered and/or double-sided, hence the increase in memory storage

• A 4.7Gb DVD can store roughly 7½ hours of CD sound or 135 minutes of MPEG-2 compressed video


DVD ROM - Compatability

DVD-ROM is backward compatible. They can play:

• CD-ROM

• CD-I

• VCD

• And CD-R


Hardware

• Input Devices• CPU (Central processing unit)• Output Devices• Memory or Storage (internal and

external)

Collectively these describe the procedures Collectively these describe the procedures known as the Information Processing known as the Information Processing

CycleCycle


Documents

Macquarie Fields College of TAFE