note01 extra2
DESCRIPTION
TRANSCRIPT
Chapter
2
Chapter
Module 2A Inside the System Unit
Module 2B Data Storage
Module 2C Input and Output
2
2
Inside the System UnitInside the System Unit
Talking about Computer Hardware The System Unit: Looking Under the hood
How Modern Computers Represent data The CPU: The Computer’s “Brain” Microprocessors: Computers on a Chip
Comparing CPUs Memory: The CPU’s Electronic Scratchpad Buses: Freeways for Data
A
Module
2
Talking about Computer Talking about Computer HardwareHardware
Computer and peripherals
Inside the System Unit
A
Module
2
The System Unit:The System Unit: Looking Under the HoodLooking Under the Hood
The system unit, exposed
Inside the System Unit
A
Module
2
How Modern Computers How Modern Computers Represent DataRepresent Data
Inside the System Unit
A
Module
Digital versus Analog Representation digital: high and low power signals analog: continuous variable scale
Numbering systemsevery numbering system has a base
2
Binary NumbersBinary Numbers
A binary number is called a binary digit, or bit. A bit is the smallest unit of information that a
computer can work with.
Inside the System Unit
A
Module
2
CountingCountingInside the System Unit
A
Module
Counting with binary, decimal, and hexadecimal numbers
Decimal numbers binary numbers hexadecimal numbers
0 0 0 1 1 1 2 10 2 3 11 3 4 100 4 5 101 5 6 110 6 7 111 7 8 1000 8 9 1001 910 1010 A11 1011 B12 1100 C13 1101 D14 1110 E15 1111 F
2
ASCII & EBCDICASCII & EBCDICInside the System Unit
A
Module
Originally used a total of 7 bits encodes a total of 128 characters included letters, numbers & punctuation
Looking for a wider marketIBM and Apple expanded to 8 bitsextended character sets not standardizedMacintosh and PC versions differ
2
Inside the System Unit
A
Module
Unicodeexpanded to 16 bits (65,000 characters)
can represent most languages Parity
extra bit added to coding systemsused to ensure code stored correctlyodd and even parity
Representing numbersfloating point notation
Representing DataRepresenting Data
2
The CPU:The CPU: Looking Under the HoodLooking Under the Hood
Inside the System Unit
A
Module
System Clockdetermines speed of the system
Instruction setlist of instructionsFour-step process (machine/processing cycle)
Arithmetic-Logic Unit (ALU)arithmetic & logical operationsregisters are temporary storage
2
Microprocessors:Microprocessors: Computers on a ChipComputers on a Chip
Inside the System Unit
A
Module
CPUs in most computers designed for individuals are microprocessors, which are complete CPUs (control unit
and ALU) fabricated on a single chip of silicon.
2
CPU CompatibilityCPU CompatibilityInside the System Unit
A
Module
Compatibilitya program that can run on a computer
Downwardly Compatiblerun programs designed for earlier chips
CPU Socketsphysically holds chip on motherboardestablished electrical connectionsupgrade socks allow upgrading processors
2
Comparing CPUsComparing CPUsInside the System Unit
A
Module
Data Bus Width & Word Sizenumber of bits in bus determines word size16-bit CPU works with 16 bit word size
CISC (complex instruction set computer)many instructions & special-purpose circuits
RISC (reduced instruction set computer)bare-bones instruction setless expensive, more efficient
2
Comparing CPUsComparing CPUsInside the System Unit
A
Module
Multitaskingprocessor runs more than one
program Pentium MMX
contains 57 sets of multimedia instructions
more quickly run games & multimedia Benchmarks
provides basis of comparison
Pentium MMX
2
Memory:Memory: CPU’s Electronic ScratchpadCPU’s Electronic Scratchpad
Inside the System Unit
A
Module
Memory Capacitieskilobyte (K or KB), megabyte (M or MB), gigabyte (G or GB)
Random-Access Memory (RAM)store programs & data being usedeach memory location has an addressvolatile
Cache Memoryallows maximum speed
2
Random Access Random Access MemoryMemory
Inside the System Unit
A
Module
In RAM, each memory location has an address, just like a post office box.
data
2
MemoryMemoryInside the System Unit
A
Module
Read-Only Memory (ROM)non-volatileROM BIOS, flash BIOS
CMOSused to store startup configuration optionseach memory location has an addressvolatile
2
Buses:Buses:Freeways for DataFreeways for Data
Inside the System Unit
A
Module
Circuits that carry data from one component to
another are called busses. The wider the bus, the more quickly
the data can flow
2
Plug and Play Plug and Play Inside the System Unit
A
Module
Microsoft and Intel created the Plug and Play (PnP) standard. This standard requires
special chips on the motherboard, compatible hardware that is expressly compatible with the Plug and Play standard, and a system
BIOS that supports Plug and Play.
2
Storage Concepts: The Basics Disks and Disk Drives: Putting a Spin on it Magnetic Tape: Still Useful Optical Storage Media: Seeing the Light
Storing Data in Files File Systems in Business: Minding the Store
Data StorageData Storage
B
Module
2
Storage Concepts:Storage Concepts:The BasicsThe Basics
Data Storage
B
Module
Device Access speed Cost per MB
MEMORY Cache memory Fastest Highest
RAM memory Fast High
STORAGE Hard disk Medium Medium
CD-ROM disc Slow Low
Backup tape Very slow Lowest
Memory versus Storage
2
Storage DevicesStorage DevicesData Storage
B
Module
Sequentialgo through fixed sequence to get dataexample: tape backup unit
Random Accesscan go directly to requested datafaster, more expensiveexample: disk drive
2
Disks & Disk Drives:Disks & Disk Drives:Putting a Spin on itPutting a Spin on it
Data Storage
B
Module
Before a disk can be used for
storage, it must be formatted
sectors
cluster tracks
2
Floppy DisksFloppy DisksData Storage
B
Module
A 3 1/2 inch disk
plastic casing
read/write openingsliding metal
shutter
write protection tab
linerdisk
spindle holesector hole
2
How Hard Disks Work Storage Capacities Physical Performance Disk Caches Hard Disk Interfaces Hard Disk Maintenance Backup Procedures Removable Hard Disks
Hard DisksHard Disks
B
Module
Data Storage
2
Hard Disk InterfacesHard Disk InterfacesData Storage
B
Module
Interface type Maximum possible data transferrate (Mbps)
Original IDE 2.1
Standard SCSI 5.0
EIDE (ATA-2) 16.6
Ultra SCSI 20.0
Ultra ATA (Ultra DMA) 33.3
Ultra Wide SCSI 40.0
2
Removable Hard DiskRemovable Hard DiskData Storage
B
Module
Many new computers come equipped with a Zip drive, a removable hard disk that uses 100MB cartridges. The cartridges cost about $10 each.
2
Magnetic Tape:Magnetic Tape:Still UsefulStill Useful
Data Storage
B
Module
Quarter-inch cartridge (QIC) tape drives work with cartridges that can hold more than 10MB of
data
2
Optical Storage Media:Optical Storage Media:Seeing the LightSeeing the Light
Data Storage
B
Module
CD-ROM disks are prerecorded and cannot be altered. CD-ROM provides an excellent way to distribute large amounts of data at little cost.
CD-ROM CD-R CD-RW
2
Optical Storage Media:Optical Storage Media:Seeing the LightSeeing the Light
Data Storage
B
Module
DVD-ROM drives are expected to replace CD-ROM drives as the standard personal
computer equipment in the near future
DVD DVD-ROM DVD-RAM
2
files
directory
Storing Data in FilesStoring Data in FilesData Storage
B
Module
Files are always named and can be
organized into directories. Just as a
filing cabinet has different drawers to
organize information, different file
directories store related types of files
Program Files Data Files
2
Configuration files Text files Graphics files Database files Sound files Backup files
Types of Data FilesTypes of Data Files
B
Module
Data Storage
2
Naming FilesNaming FilesData Storage
B
Module
File names can contain up to 255 characters as well as spaces and some punctuation. The characters \ / : * ? “ < > | cannot be used.
Microsoft Windows 95, 98, and NT
File names have a 31-character limit. This limitation allows a more descriptive name than with MS-DOS or Windows 3.1, but not as descriptive as Windows 95.
Macintosh
2
Organizing Files into Organizing Files into Folders Folders (Directories)(Directories)
Data Storage
B
Module
By viewing the directory, you can get information about the files stored on the disk.
This information includes the file name,
the file size, and the date and time of the
file’s creation and last update
2
Organizing Files into Organizing Files into Folders Folders (Directories)(Directories)
Data Storage
B
Module
In Microsoft Windows 95 & 98, the root directory contains several subdirectories, including a Windows
directory and a Program Files directory
2
The Data Storage The Data Storage HierarchyHierarchy
Data Storage
B
Module
The data storage hierarchy
8 bits = A
Last name field
Four fields = 1 recordRecords
combined = file
2
Transaction filebatch processingreal-time processing
Master file Report file
Types of Files in Data Types of Files in Data Processing ApplicationsProcessing Applications
B
Module
Data Storage
2
Sequential File Sequential File OrganizationOrganization
Data Storage
B
Module
The computer processes a sequential file in the order
in which the data was encoded in the file
0452 0453 0454data data
Key field
2
Direct (Random) File Direct (Random) File OrganizationOrganization
Data Storage
B
Module
Records in a direct access file are stored according to a position in the file. Every location in primary & secondary storage is assigned a unique address.
Location of record on disk
2
Indexed Sequential File Indexed Sequential File OrganizationOrganization
Data Storage
B
Module
With indexed sequential
files, records can be
accessed either directly (randomly) or sequentially.
2
Understanding Input: Not Just Data Entry Input Devices: The Computer’s “Senses”
Input Devices in Business & Industry Biological Feedback Devices Chemical Detectors Output Devices: Engaging Our Senses
Printers Sound Cards & Speakers Tactile Feedback
Input and OutputInput and Output
C
Module
2
Keyboardsnumeric keyboardfunction keystoggle keysCaps Lock keystatus indicators
Input Devices:Input Devices:The Computer’s “Senses”The Computer’s “Senses”
C
Module
Input &
Output
2
Cursor & Cursor Movementsinsertion pointcursor movement keys (arrow keys)repetitive strain injury (RSI)/cumulative
trauma disorder (CTD)
Input Devices:Input Devices:The Computer’s “Senses”The Computer’s “Senses”
C
Module
Input &
Output
Ergonomic keyboards help prevent CTD
2
Mouse operationsClickingDraggingDouble-Clicking
Pointing DevicesPointing Devices
C
Module
Input &
Output
click
click
click
2
Pointing DevicesPointing Devices
C
Module
Input &
Output
Trackball Trackpoint Touchpad Touch-Sensitive Screens Pen-Based Systems
2
Additional Input Additional Input DevicesDevices
C
Module
Input &
Output
Soundcards Microphones & Speech Recognition Video Capture Cards Cameras Scanners
Handheld scanner
2
Input Devices in Input Devices in Business & IndustryBusiness & Industry
C
Module
Input &
Output
source data automation image processing systems magnetic ink character recognition (MICR)
bar code readers universal product code mark sense character recognition optical mark reader (OMR)
2
Additional Input Additional Input DevicesDevices
C
Module
Input &
Output
Biological feedback devices Chemical detectors
Virtual reality programs use helmets
to enable users to “move” through a simulated “world.”
2
Video Adaptersvideo RAM (VRAM)video graphics adapter (VGA)super VGArefresh rateflicker
Output Devices:Output Devices:Engaging Our SensesEngaging Our Senses
C
Module
Input &
Output
2
Video Graphics AdapterVideo Graphics Adapter
C
Module
Input &
Output
Common PC resolutions
640 x 480
800 x 600
1024 x 768
1600 x 1200
2
Video Graphics AdapterVideo Graphics Adapter
C
Module
Input &
Output
Common color depthColor Depth Number of colors
VGA (4 bits) 16
256 Color Mode (8 bits) 256
High Color (16 bits) 65,536
True Color (24 bits) 16,777,216
2
MonitorsMonitors
C
Module
Input &
Output
cathode ray tube (CRT) liquid crystal display (LCD)
Laptop color LCD display
Desktop computers use a CRT
2
Screen SizeScreen Size
C
Module
Input &
Output
Quoted Size and Actual Viewable Area
Monitor Size Viewable Area
21 inches 20 inches
17 inches 16 inches
15 inches 14 inches
2
Additional Monitor Additional Monitor CharacteristicsCharacteristics
C
Module
Input &
Output
dot pitch interlaced monitors noninterlaced monitors multiscan monitors
2
Impact PrintersImpact Printers
C
Module
Input &
Output
Line letter-quality dot-matrix
2
Nonimpact PrintersNonimpact Printers
C
Module
Input &
Output
inkjet laser thermal transfer dye sublimation snapshot multifunction
2
Additional Output Additional Output DevicesDevices
C
Module
Input &
Output
plotters sound cards and speakers tactile feedback
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