Computer Hardware and Software

• All the electronic and mechanical equipment in a computer constitutes the hardware

Hardware Examples

• Includes the motherboard, hard disk, RAM, power supply, processor, case, monitor, keyboard, and mouse

• Software comprises computer programs that execute tasks on a computer system

Software Groups:

• System software includes operating systems

• Utility programs include antivirus software

• Application software includes Word and SolidWorks

• A computer system integrates electronic and mechanical devices as a unit

PC Components

• The main components are the system unit, monitor, keyboard, mouse, and speakers

• The system unit is a container for system devices, protecting them from damage

System Unit Devices:

• Includes the motherboard, CPU (processor), memory, disk drives, ports (USB, etc.), power supply, and expansion cards such as sound, network, and graphics cards

• Peripherals connect to the system unit via cables or wirelessly

Peripherals Examples:

• Includes monitors, keyboards, printers, plotters, scanners, and speakers

• An integrated circuit (IC) on a silicon chip controls all computer functions

System Devices

• The function controls all the computer actions

• Main processor manufacturers include AMD (Athlon, Turion) and Intel (Pentium, Centrino)

• A computer program is a sequence of instructions that the processor executes in order

Common Instructions:

• Arithmetic for calculations

• Logical for comparing data

• Move for data transfer within the system

• Processor speed, or clock speed, determines how fast instructions are executed, measured in megahertz (MHz) or gigahertz (GHz)

Measurements:

• 1 MHz equals 1 million clock ticks per second

• 1 GHz equals 1 billion clock ticks per second

• The latest trend involves multi-core processors with multiple cores on a single chip

• Random Access Memory (RAM) is the main computer memory for active data and programs

Primary Storage

• RAM is a volatile memory, losing its contents when the computer is off

• RAM is typically installed as memory ICs on a circuit board module

• DIMMs (Dual Inline Memory Modules) are used for desktop computers

Memory Modules

• SODIMMs (Small Outline Dual Inline Memory Modules) are used for notebook computers

• DIMMs and SODIMMs come in modules of various sizes like 256MB, 512MB, 1GB, and 2GB

DDR

• Current memory tech is DDR (Double Data Rate) RAM, including DDR1, DDR2, and DDR3

• A computer system is compatible with only one type of DDR RAM

• The motherboard is the main circuit board of the computer system

Key Components

• All devices either reside on or connect to the motherboard

• Different processors require specific sockets

Motherboard Sockets:

• Socket 478 supports Intel Pentium IV

• Socket 775 supports Intel Dual Core and Core Duo

• Socket 754 supports AMD Athlon

• Socket 939 supports AMD Athlon 64

• Socket AM2 supports AMD Athlon X2

• The chipset manages data flow, comprising the Northbridge and Southbridge

• The Northbridge manages data flow between memory, the processor, and the graphics card

Northbridge and Southbridge:

• The Southbridge manages data flow to USB, IDE, SATA, LAN, audio, and PCI slots
• Busses are pathways for data transfer within the computer system

Motherboard Connections/Connectors

• Main connector: supplies 3.3V and 5V power to the board

• Molex connector: connects IDE hard drives and optical drives

• Berg connector: connects floppy disk drives

• SATA connector: connects SATA drives

• Computer ports serve as interfaces for peripheral devices

Ports:

• Found at the back of the computer for easy access

• Serial ports (9-pin) were used for mice and external modems

Serial Ports

• Known as Comm ports, are now largely obsolete

• Parallel ports (25-pin) connect printers, scanners, and external hard disks

Parallel Ports

• Called LPT ports, now largely obsolete

• Video ports connect a monitor

Video Ports

• VGA ports (15-pin, blue) are analogue and are being replaced by DVI

• DVI ports (white) are digital, allowing faster image production without conversion

• PS/2 ports connect keyboards (purple) and mice (green)

• Modem ports connect modems to telephone lines using RJ11 connectors

• USB ports are intended to replace serial, parallel, and PS/2 ports

• Hot swappable, allowing devices to be connected/disconnected while the computer is on

USB Standards

• USB 1: original standard, 1.5MBps transfer rate

• USB 2: current standard, 60MBps transfer rate

• USB 3: future standard (2009), 600MBps transfer rate

• FireWire (IEEE 1394) is an Apple technology with multiple versions

FireWire Versions

• FW 400: 50MBps transfer rate

• FW 800: 100MBps transfer rate

• FW S3200: 400MBps transfer rate

• USB devices need a host computer; FireWire devices can connect without one

• Ethernet ports (RJ45) connect to a network, larger than modem ports

Audio Ports

• Audio ports handles audio input/output with color-coded mini jacks

• Light blue: Line-in for external devices

• Lime: Connect speakers

• Pink: Connect a microphone

• PCI-Express (PCIe) is faster than AGP, used for two graphics cards (SLI) and can output analogue or digital signals

Graphics card slots

• Slots are mutually exclusive, determined by the motherboard

• Sound cards convert analogue/digital signals for audio input/output

Functions of Sound Cards

• DAC (Digital to Analogue Converter): Prepares audio for speakers
• ADC (Analogue to Digital Converter): Convert the audio coming into the computer

Sound Card Connections:

• Microphone, Radio, Tape deck, record player

• Headphones and speakers - connects to a tape etc

• Network cards enable computers to join a network wired or wireless

Network Standards

• Ethernet covers wired and wireless networks

Wired Standards

• Fast Ethernet transmits at 100MBps

• Gigabit Ethernet transmits at 1000MBps

• Wireless standards vary in speed and range

Wireless Standards

• B transmission at 11MBps, 30m range, introduced in 1999

• G transmission at 54MBps, 30m range, introduced in 2003

• N transmission at 540MBps, 50m range, introduced in 2006

• Modems connect to the Internet via telephone lines, converting digital to analogue (modulation) and vice versa (demodulation)

Modems

• The name comes from modulation/demodulation

• Transmission speed is capped at 56Kbps

• Primary storage (memory) is volatile, losing data when power is off

Hard Disk

• Secondary storage (disk drives) retain data without power

Hard Disk

• Employs magnetism rather than voltages to store binary data
• Metal disks (platters) coated with magnetisable iron particles represent 0 and 1

Read-Write

• Read-write heads magnetize particles to store data
• Hard disks can be internal or external

Internal Standards

• IDE (Integrated Drive Electronics) connect with ribbon cables, supporting master/slave configurations

• SATA (Serial Advanced Technology Attachment) offers speed, individual cabling, and better air circulation

• External hard drives use IDE or SATA, powered by mains or USB

Powering External Hard Drives

• Host-powered drives draw power from the USB port

• Optical drives use lasers to read mechanically pressed pits and lands on polycarbonate disks

Optical Drives

• These pits/lands store binary data
• A metal layer reflects laser light
• Disks operate at a single laser intensity, sensing pits and lands

Disks

• CD-R discs use a dye layer to simulate pits and lands, written with two laser intensities

• High setting burns spots for opacity

• Low setting reads differences

• CD-RW disks can rewrite data using three laser intensities

Laser intensities

• Intensity 1: Read data
• Intensity 2: Burn data
• Intensity 3: Erase data

Storage Capacity

• CD-R disks hold 650-800MB

• DVDs hold more data, using multiple layers of 4.7GB each

• Dual-layer disks use reflective layers, one penetrable at certain intensities

• Resolution standards for monitors

DVD Format

• DVD-ROMs are read-only, manufactured as single or double layer disks, with single-sided or double-sided options

DVD-R

• DVD-Rs Disks can be single or dual-layer, permitting data writing once

• DVD-RW disks support rewriting numerous times

DVD Disks

• DVD+R can hold data in single or dual layers with single-sided/double-sided options, with the ability to write data one time

DVD Disks

• DVD+RW can be overwritten multiple times

DVD Disks

• DVD-R and DVD+R are inconsistent, so manufacturers make DVD±R drives compatible with both standards

High Capacity Formats

• HD-DVD uses laser tech to give 15 GB/layer against DVD. It has 60 GB capacity with double-sided and double layered disk

Blu-Ray

• Blu-Ray has 25GB/layer and dual layered disks can hold 50GB

Card Readers

• Card readers serve as replacements of floppy drives in PCs and these can read media cards from the digital cameras of various manufacturers

Card Readers

• Microdrive, Smartmedia, SD memory card, Memory stick/Duo/Pro and XD picture card

Monitors

• Computer monitors render images arising from the graphics card of the computer

Monitors

• The monitors are predominantly LCD but CRT monitors have more value now

Aspect Ratios

• Aspect ratio is a parameter of comparison between the monitor screen's width and height

Ratios

• 4:3 standard; 16:9 - Widescreen

Connections

• Most of LCD monitors offer VGA and DVI cable attachment. VGA connecter for analogue signal while DVI used for digital
• The best option for the computer is DVI connection

Resolution Standard (Monitors)

• XGA (Extended Graphics Array) - 1024 x 768
• SXGA (Super Extended Graphics Array) - 1280 x 1024
• UXGA (Ultra Extended Graphics Array) - 1600 x 1200
• QXGA (Quad Extended Graphics Array) - 2048 x 1536

Widescreen Monitors

• WXGA (Wide XGA) - 1280 x 800
• WSXGA (Wide SXGA) - 1680 x 1050
• WUXGA (Wide UXGA) - 1920 x 1200

LCD Monitors

• LCD screens operate at original resolutions or clarity gets reduced

Keyboards

• Keyboard is divided into sections

Dividing Sections

• Typing keys - letters, numbers, shift, space bar etc
• Numeric keypad - arranged on calculator
• Function keys - programmed keys used with software
• Control keys - cursor control button

Keyboards Arrangement

• The most common arrangement of keyboarding is QWERTY but additional arrangements are present

Keyboards Availability

• wired using PS/2 OR USB
• wireless using batteries

Rubber Keyboards

• Serves best with the use of notebooks and it is proven safe for RSI (Repetitive Strain Injury)

• Mouse is an input device known for point and click functions and there exist two main categories

Mouse Input Techniques

• Ball Mouse - ball goes over a specific surface, in order to move rollers and get to the cursor movement
• Optical Mouse - Camera takes thousands of images which are sent for processing to digitally light the camera in the surface area of contact

Printers

• Printers function as output devices
• It produces a hard copy of any material on paper and the two prime techniques include

Printers Technologies

• Inkjet (Bubble-Jet)

• Laser

• Inkjet printers use electricity to vibrate a membrane, expelling ink through a nozzle

Injet printers

• Ink is drawn into the reservoir with the membrane upward movement

Bubblejet

• A heating element heats ink, forming bubbles that force ink through the nozzle

• Vacuum draws ink into the reservoir

• Laser printers use toner (powdered ink) instead of

Laser Printer Technique

• A laser beam, mirror and lens creates the image
• The image is transferred from the drum to the paper and then fused

Printers Availability

• A2, A3 and A4 configurations are a must but if images and large drawings are in requirement go for a plotter

Plotters

• Comes in three basic models that include A0, A1, A2, A3
• Plotters cost more as compared to inkjet printers because of their efficiency and space