Input, Process, Output

Supplemental Lecture Notes

Typical System

Computer case

Monitor

Printer

Speakers

Modem

Keyboard

Mouse

Computer ComponentsPower supplyHard driveExpansion cardExpansion slotSystem boardCD-ROM or DVD-ROMFloppy diskDrive bayCentral Processing Unit (CPU)Random access memory (RAM)

Power Plays

The capacity of a power supply is measured in watts

Computer uses 250; light bulb uses 60

Can useSurge protector

UPS

Ports

Ports are connectors at the back of a computer system that you use to plug in an external device. This allow instructions and data to flow between the computer and the device

Any Port in a Storm

Parallel port – 25 holes; female connector; LPT1; printer or storage devicesMonitor portKeyboard portSerial port – 9 or 25 pins; male connector; COM1; mouse or modemGame portNetwork portUSB port

127 devicesPrinter, modem, joy stick

Growing

An expansion card is a circuit board that lets you add new features to a computer

Video

Modem

Sound

Network Interface

Upgrades

Upgrading refers to replacing an old or obsolete component with a newer component to improve the efficiency of the computer

Upgrading also can include adding a new component like a tape drive or DVD to increase the capabilities of a computer

Increasing the amount of memory in a computer is one of the most effective upgrades you can perform

Input and Output

Chapter 2

Mouse Actions

Click – selects

Right click – displays commands

Double click – opens

Drop and Drag – moves items on screen

Mice

TypesConventionalWheel mouseWireless mouseProgrammable mouse – e.g. three buttonsOptical sensor mouse

Other devicesTouchpadTrackballPointing stick

KeyboardsThere are 101 keys on a keyboard to help you input informationFunction keys let you perform specific taskCan use CNTL-x shortcuts to execute commands

CNTL-C – copyCNTL-X – cutCNTL-V – paste

Windows key will quickly display the start menu

Printers

Speed of a printer is measured in pages per minute (PPM). A higher speed represents faster output

Resolution determines the quality of imagesA higher resolution results in sharper images

Printer resolution is measured in dots per inch (dpi)600 dpi is acceptable; 1200 is better for images

Resolution expressed with two numbers represents dots per inch across and down

Types of PrintersInk-jet: has a print head that sprays ink through tiny nozzles onto a page

2 to 10 pages (ppm)360 to 2400 dots per inchColor printers spray cyan, magenta, yellow and black to create different colors

Laser-printerWorks like a photo copierSpeed of 4 to 16 pagesHave a CPU600 to 2400Memory – 2mb to 8 Mb

Other Types

Dot matrixPrint head contains small blunt pins that strike an inked ribbon

Useful for multi-part forms

LED printerSimilar to lasers but cheaper

Color photo printerMultifunction Printer

Print Buffer and Spoolers

Printer buffer: section of memory printer stores information waiting to print

Printer spooler: program on your computer that stores information waiting to print

Stores more information than the buffer

One spooler for each connected printer

Monitors

Video cards translate instructions from the computer into a form Most computes the monitor can understand

require at least 2 mb of video card memory

Accelerated Graphics Port (AGP) – uses AGP bus to communicate directly with main memory

3D Graphics Accelerator has chip called a GPU optimized for 3-D graphics

Monitor Metrics

The smaller the dot pitch, the crisper the image

0.28mm is acceptable

Refresh rate is measured in hertz (Hz)Times per second computer redraws the image

72 Hz or more is acceptable

Resolution

Amount of information a monitor can displayMeasured by the number of horizontal and vertical pixels

Monitors switch settings based on the resolution and refresh rate of video card

Video card determines number of colors a monitor can display

256 suitable for most home use

24-bit displays more colors than eye can distinguish

CommunicationsModems let a computer exchange information through telephone linesSpeed of a modem determines how fast it sends and receives messages

56,000 bps (56 Kbps)V.90 standard: receive 56K and send 33.6K

Speed at which information flows depend on the quality of the phone line

A modem needs a communications package to manage the transmission of informationData compression – squeezes together data

High-speed ConnectionsISDN – Integrated Services Digital Network

Digital phone line

56 Kbps to 128 Kbps

Cable ModemSame cable as TV

4000 Kbps

DSL – Digital subscriber lineHigh speed digital phone line

1000 – 6000 Kbps

Satellite

Sound Cards

Sampling Rate: at least 44.1 KHz

Full-duplexTalk and listen at same time

Musical Instrument Digital Interface (MIDI) support

Wavetable synthesisActual recordings

FM synthesisImitated sounds

TV Tuner Cards

Require a video card to operate

ScannersA scanner is a device that reads images and text into a computer

Most scanners come with Optical Character Recognition (OCR) software. This software places scanned text into a document that can be edited in a word processorColor dept is measured in bits and indicates the number of colors a scanner can detect

36 bit color depth is acceptable

Resolution

Resolution determines the amount of detail a scanner can detect

Ranges from 600 dpi to 2400 dpi

You usually don’t need to scan at a higher resolution than a printer can produce or a monitor can display

– Most monitors are 73 dpi

– Printers vary

Cameras

Resolution is measured in megapixels1000 x 1000 pixels1, 2 and 3 megapixel cameras are available

Digital video cameras use a Charged Coupling Device (CCD) to capture video

Quality depend on amount of detail a CCD can detectMost CCD’s have resolution between 250,000 and 700,000 pixels

Web cameras – resolution and speed determine quality of image

Common transfer rates15 frames per second at 640 x 480 pixels30 frames per second at 352 x 288 (clearer but smaller)

MP3

Sound format used to CD-quality music over the Internet

Compresses sound

Commonly 64 bit memory

USB and Firewire

High-speed ports that allow information to quickly transfer between a computer and an external device

USBSupports up to 127 device

– USB 1.0: 12 megabits per second

– USB 2.0: 480 Mbps

FIREWIRE63 devices at 400 Mbps

Can purchase Firewire expansion card

Processing

Chapter 3

CPU (Central Processing Unit)Processes instructions, performs calculations, and manages the flow of information Performance:

CPU speed is a major factor in determining how fast a computer operates (faster the speed, faster computer operates)

Measured in megahertz (MHz) A clock cycle relates to the clock that controls the timing in the microprocessor. For example, a 900MHz (megahertz) clocked microprocessor generates 900 million clock cycles per second.

Each generation of CPU is more powerful than the one before. It's clock cycles are faster at a given speed

Processing

The Central Processing Unit (CPU) is the main chip in a computer

Processes instructions

Performs calculations

Manages the flow of information

Types of CPUsIntel Pentium Processor

Speeds of 450 MHz to 1.13 GHz

Intel CeleronNeeds of home machines (500-700MHz)

AMD Athlon ProcessorBusiness and home use

AMD Duron ProcessorHome use

VIA Cyrix ProcessorInexpensive CPU

ProcessingRandom Access Memory – Temporarily stores data inside a computer

Constantly overwrittenMeasured in megabytes (MB)

64 minimum these days100 MHz (millions of cycles per second)

Dynamic RAM is type of memory chip that makes up memory in many computer systems. Access speed measured in megabits

Most system boards can support access speed of Single Inline Memory Module (SIMM) – 9 memory chipsDual Inline Module (DIMM) – 18 memory chips

If you have limited memory or you have many programs open, your computer may need to use part of the hard drive to simulate more memory

Using Memory Cache

1. Look through documents on your desk (internal cache)

2. Look through documents in your desk drawer (external cache)

3. Looking through documents in your filing cabinet (RAM)

Using Memory Cache

1. Look through documents on your desk (internal cache)

2. Look through documents in your desk drawer (external cache)

3. Looking through documents in your filing cabinet (RAM)

Math CoprocessorsA special processing unit that assists the CPU in performing certain operations.

A math coprocessor is a chip or part of a chip that specializes in doing math. Hardware that attaches to the motherboard or is part of the CPU.

Extends the capabilities of a CPU in a transparent manner. Performs mathematical computations, particularly floating-point operations. Besides being able to add, subtract, multiply and divide floating-point numbers, they can also operate on them to perform comparisons, square roots, logarithms, sine, cosine, tangent, absolute value, and remainders

Also called numeric coprocessors or floating point units (FPU).