Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill Technology Education Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.

McGraw-Hill Technology Education Chapter 3; Lesson A Transforming Data Into Information

3A-3 How Computers Represent Data Number systems –A manner of counting –Several different number systems exist Decimal number system –Used by humans to count –Contains ten distinct digits –Digits combine to make larger numbers

3A-4 How Computers Represent Data Bits and bytes –Binary numbers are made of bits –Bit represents a switch –A byte is 8 bits –Byte represents one character

3A-5 How Computers Represent Data Text codes –Converts letters into binary –Standard codes necessary for data transfer –EBCDIC Used in mainframe and midrange systems –ASCII American English symbols –Extended ASCII Graphics and other symbols –Unicode All languages on the planet

3A-6 How Computers Process Data The CPU –Central Processing Unit –Brain of the computer –Control unit Controls resources in computer Instruction set –Arithmetic logic unit Simple math and comparison operations Registers to hold data

3A-7 How Computers Process Data Memory –Stores open programs and data –Small chips on the motherboard –More memory makes a computer faster

3A-8 How Computers Process Data Nonvolatile memory –Holds data when power is off –Read Only Memory (ROM) –Basic Input Output System (BIOS) –Power On Self Test (POST)

3A-9 How Computers Process Data Flash memory –Data is stored using physical switches –Special form of nonvolatile memory –Camera cards, USB key chains

3A-10 How Computers Process Data Volatile memory –Requires power to hold data –Random Access Memory (RAM) –Data in RAM has an address –CPU reads data using the address –Stored on DIMMS or SO-DIMMS

3A-11 Components affecting Speed

3A-12 Affecting Processing Speed Registers –Number of bits processor can handle –Word size –Larger indicates more powerful computer –Increase by purchasing new CPU

3A-13 Affecting Processing Speed Virtual RAM –Computer is out of actual RAM –File that emulates RAM –Computer swaps data to virtual RAM Least recently used data is moved

3A-14 Affecting Processing Speed The computer’s internal clock –Quartz crystal –Every tick runs an instruction –Speeds measured in Hertz (Hz) Modern machines use Giga Hertz (GHz)

3A-15 Affecting Processing Speed The bus –Electronic pathway between components –Expansion bus connects to peripherals –System bus connects CPU and RAM –Data bus connects CPU to hardware –Bus width is measured in bits –Speed is tied to the clock

3A-16 Affecting Processing Speed Cache memory –Very fast memory –Holds common or recently used data –Speeds up computer processing –Most computers have several caches –L1 holds recently used data –L2 holds upcoming data –L3 holds possible upcoming data

3A-17 A Look Inside The Processor Architecture –Determines Location of CPU parts Bit size Number of registers Pipelines –Main difference between CPUs

3A-18 Microcomputer Processors Intel –Leading manufacturer of processors –Intel 4004 was worlds first microprocessor –IBM PC powered by Intel 8086 –Current processors Centrino Itanium Pentium IV Xeon

3A-19 Microcomputer Processors Advanced Micro Devices (AMD) –Main competitor to Intel –Originally produced budget products –Current products outperform Intel –Current processors Sempron Athlon FX 64 Athlon XP

3A-20 Microcomputer Processors Freescale –A subsidiary of Motorola –Co-developed the Apple G4 PowerPC –Currently focuses on the Linux market

3A-21 Microcomputer Processors IBM –Historically manufactured mainframes –Partnered with Apple to develop G5 First consumer 64 bit chip

3A-22 Comparing Processors Speed of processor Size of cache Number of registers Bit size Speed of Front side bus

3A-23 Extending The Processors Power Standard computer ports –Keyboard and mouse ports –USB ports –Parallel –Network –Modem –Audio –Serial –Video

3A-24 Standard Computer Ports

3A-25 Extending The Processors Power Serial and parallel ports –Connect to printers or modems –Parallel ports move bits simultaneously Made of 8 – 32 wires Internal busses are parallel –Serial ports move one bit Lower data flow than parallel Requires control wires UART converts from serial to parallel

3A-26 Serial Communications

3A-27 Parallel Communications

3A-28 Extending The Processors Power SCSI –Small Computer System Interface –Supports dozens of devices –External devices daisy chain –Fast hard drives and CD-ROMS

3A-29 Extending The Processors Power USB –Universal Serial Bus –Most popular external bus –Supports up to 127 devices –Hot swappable

3A-30 Extending The Processors Power FireWire –IEEE 1384 –Cameras and video equipment –Hot swappable –Port is very expensive

3A-31 Extending The Processors Power MIDI –Musical Instrument Digital Interface –Allows musical instruments to communicate –Instruments can be connected to a PC –Allow recording and playback of music

3A-32 Extending The Processors Power Expansion slots and boards –Allows users to configure the machine –Slots allow the addition of new devices –Devices are stored on cards –Computer must be off before inserting

3A-33 Extending The Processors Power PC Cards –Expansion bus for laptops –PCMCIA –Hot swappable –Small card size –Three types, I, II and III –Type II is most common

3A-34 Describing Storage Devices Store data when computer is off Two processes –Writing data –Reading data

3A-35 Describing Storage Devices Storage terms –Media is the material storing data –Storage devices manage the media –Magnetic devices use a magnet –Optical devices use lasers –Solid-state devices have physical switches

3A-36 Magnetic Storage Devices Most common form of storage Hard drives, floppy drives, tape All magnetic drives work the same

3A-37 Magnetic Storage Devices Floppy Disk Hard Disk Tape

3A-38 Magnetic Storage Devices Data storage and retrieval –Media is covered with iron oxide –Read/write head is a magnet –Magnet writes charges on the media Positive charge is a 1 Negative charge is a 0 –Magnet reads charges –Drive converts charges into binary

3A-39 Data Retrieval

3A-40 Magnetic Storage Devices Data organization –Disks must be formatted before use –Format draws tracks on the disk –Tracks is divided into sectors Amount of data a drive can read

3A-41 Tracks and Sectors

3A-42 Magnetic Storage Devices Finding data on disk –Each track and sector is labeled Some are reserved –Listing of where files are stored File Allocation Table (FAT) FAT32 NTFS –Data is organized in clusters Size of data the OS handles

3A-43 Magnetic Storage Devices Diskettes –Also known as floppy disks –Read with a disk drive –Mylar disk –Spin at 300 RPM –Takes.2 second to find data –3 ½ floppy disk holds 1.44 MB

3A-44 Magnetic Storage Devices Hard disks –Primary storage device in a computer –2 or more aluminum platters –Each platter has 2 sides –Spin between 5400 to RPM –Data found in 9.5 ms or less –Drive capacity greater than 40 GB

3A-45 Illustrated Hard Disk

3A-46 Magnetic Storage Devices Removable high capacity disks –Speed of hard disk –Portability of floppy disk –Several variants have emerged –High capacity floppy disk Stores up to 750 MB of data –Hot swappable hard disks Provide GB of data Connect via USB

3A-47 Magnetic Storage Devices Tape drives –Best used for Infrequently accessed data Backup solutions –Slow sequential access –Capacity exceeds 200 GB

3A-48 Optical Storage Devices CD-ROM –Most software ships on a CD –Read using a laser Lands, binary 1, reflect data Pits scatter data –Written from the inside out –CD speed is based on the original Original CD read 150 Kbps A 10 X will read 1500 Kbps –Standard CD holds 650 MB

3A-49 Optical Storage Devices DVD-ROM –Digital Video Disk –Use both sides of the disk –Capacities can reach 18 GB –DVD players can read CDs

3A-50 Recordable Optical Technologies CD Recordable (CD-R) –Create a data or audio CD –Data cannot be changed –Can continue adding until full

3A-51 Recordable Optical Technologies CD Re-writable (CD-RW) –Create a reusable CD –Cannot be read in all CD players –Can reuse about 100 times

3A-52 Recordable Optical Technologies Photo CD –Developed by Kodak –Provides for photo storage –Photos added to CD until full –Original pictures cannot be changed

3A-53 Recordable Optical Technologies DVD Recordable –Several different formats exist –None are standardized –Allows home users to create DVDs –Cannot be read in all players

3A-54 Recordable Optical Technologies DVD-RAM –Allow reusing of DVD media –Not standardized –Cannot be read in all players

Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill Technology Education Chapter 3; Lesson A End of Lesson