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CHAPTER 2 Section A Data Representation and Digital Electronics PARSONS/OJA Computer Hardware Computer Concepts CHAPTER 2 Section A Data Representation and Digital Electronics PARSONS/OJA Computer Hardware Computer Concepts Parsons/Oja Page 58

Computer Hardware Chapter 2 Chapter PREVIEW • When you complete this chapter, you should Computer Hardware Chapter 2 Chapter PREVIEW • When you complete this chapter, you should be able to: • Explain why most computers are digital • Describe the role of the ALU • List factors that affect performance • Explain RAM • Compare storage technologies • Describe computer’s expansion bus • Explain hardware compatibility considerations • Compare and contrast technologies for peripherals Computer Concepts Parsons/Oja Page 57

Chapter 2 Section A Data Representation and Digital Electronics Digital Data Representation: Why are Chapter 2 Section A Data Representation and Digital Electronics Digital Data Representation: Why are computers digital? • Data representation makes it possible to convert letters, sounds, and images into electrical signals • Digital electronics makes it possible for computer to manipulate simple “on” and “off” signals to perform complex tasks • A digital device works with discrete data or digits, such as 1 and 0 • An analog device works with continuous data such as sound waves Computer Concepts Parsons/Oja Page 58

Chapter 2 Section A Data Representation and Digital Electronics Why are computers digital? • Chapter 2 Section A Data Representation and Digital Electronics Why are computers digital? • Computers are digital primarily because digital technology is simple, dependable, and adaptable • Just as a standard light switch is a simpler technology than a dimmer, so is digital when compared to analog Computer Concepts Parsons/Oja Page 58

Chapter 2 Section A Data Representation and Digital Electronics Why are computers digital? • Chapter 2 Section A Data Representation and Digital Electronics Why are computers digital? • A computer uses a bit (binary digit) as the building block for more complex data representations • By grouping bits together, computers create sequences that represent numbers, letters, pictures, music, and more Computer Concepts Parsons/Oja Page 58

Chapter 2 Section A Data Representation and Digital Electronics How can a computer represent Chapter 2 Section A Data Representation and Digital Electronics How can a computer represent numbers using bits? • Unlike the decimal system, the binary number system (base 2) uses only two digits 0, and 1. • The following table lists some decimal numbers and their binary equivalent: Computer Concepts Parsons/Oja Page 59

Chapter 2 Section A Data Representation and Digital Electronics How can a computer represent Chapter 2 Section A Data Representation and Digital Electronics How can a computer represent words and letters using bits? • Character data is composed of letters, symbols, and numerals that will not be used in arithmetic operations • ASCII (American Standard Code for Information Interchange) requires only 7 bits for each character • Extended ASCII uses eight bits for each character Computer Concepts Parsons/Oja Page 59 -60

Chapter 2 Section A Data Representation and Digital Electronics How can a computer represent Chapter 2 Section A Data Representation and Digital Electronics How can a computer represent words and letters using bits? • EBCDIC (Extended Binary-Coded Decimal Interchange Code) is an alternative 8 -bit used by older IBM systems • Unicode uses 16 bits and provide codes for 65, 000 characters – a bonus for representing alphabets of multiple languages • Used foreign language support Computer Concepts Parsons/Oja Page 60

Chapter 2 Section A Data Representation and Digital Electronics How can a computer represent Chapter 2 Section A Data Representation and Digital Electronics How can a computer represent words and letters using bits? extended ASCII table Computer Concepts Parsons/Oja Page 60

Chapter 2 Section A Data Representation and Digital Electronics Why does ASCII provide codes Chapter 2 Section A Data Representation and Digital Electronics Why does ASCII provide codes for 1, 2, 3, 4, 5, 6, 7, 8, and 9? • Numerals are distinguished from numeric data • Numerals are not used in calculations and are considered to be character data • Examples • Student ID • Zip code • Street Address Computer Concepts Parsons/Oja Page 61

Chapter 2 Section A Data Representation and Digital Electronics How does a computer convert Chapter 2 Section A Data Representation and Digital Electronics How does a computer convert sounds and pictures into codes? • Sounds and pictures must be transformed into a format the computer can understand • A computer must digitize colors, notes, and instrument sounds into 1 s and 0 s Computer Concepts Parsons/Oja Page 61

Chapter 2 Section A Data Representation and Digital Electronics When a computer works with Chapter 2 Section A Data Representation and Digital Electronics When a computer works with a series of 1 s and 0 s, how does it know which code to use? • Most computer files contain a file header • A file header contains the information on the code that was used to represent the file data • It is read by the computer but never appears on the screen Computer Concepts Parsons/Oja Page 61

Chapter 2 Section A Data Representation and Digital Electronics Quantifying Bits and bytes: How Chapter 2 Section A Data Representation and Digital Electronics Quantifying Bits and bytes: How can I tell the difference between bits and bytes? • A bit is one binary digit (b) • 0 • A byte is 8 bits (B) • 0010 0100 • A nibble is 4 bits • 0011 Computer Concepts Parsons/Oja Page 61

Chapter 2 Section A Data Representation and Digital Electronics What do the prefixes kilo- Chapter 2 Section A Data Representation and Digital Electronics What do the prefixes kilo- mega- and giga- mean? • Kilo- means a 1000, Mega- means million, Giga means billion, Tera- means trillion, and Exameans quintillion • Kilobit (Kb) is 1, 024 bits • Kilobyte (KB) is 1, 024 bytes • Megabyte(MB) is 1, 048, 576 bytes Computer Concepts Parsons/Oja Page 61

Chapter 2 Section A Data Representation and Digital Electronics: How does a computer store Chapter 2 Section A Data Representation and Digital Electronics: How does a computer store and transport all of those bits? • A computer stores bits as electronic pulses that can travel over circuits and wires Computer Concepts Parsons/Oja Page 62

Chapter 2 Section A Data Representation and Digital Electronics Does a typical computer owner Chapter 2 Section A Data Representation and Digital Electronics Does a typical computer owner need to mess around inside the system unit? • Desktop units are designed with expectation that the home user may add or update the equipment • Notebook and Palm. Pilot computers are not designed for users to access all areas. Although users can update certain components Computer Concepts Parsons/Oja Page 62

Chapter 2 Section A Data Representation and Digital Electronics Does a typical computer owner Chapter 2 Section A Data Representation and Digital Electronics Does a typical computer owner need to mess around inside the system unit? Power supply and fan CD-ROM drive Floppy disk drive Microprocessor build under cooling fan Hard disk drive Cables that transfer data from storage devices to motherboard Expansion cards Main circuit board (motherboard) Computer Concepts Parsons/Oja Page 62

Chapter 2 Section A Data Representation and Digital Electronics What’s a computer chip? • Chapter 2 Section A Data Representation and Digital Electronics What’s a computer chip? • Most electronic components inside a computer are integrated circuits - thin slices of silicon crystal packed with microscopic circuit elements • Wires • Transistors • Capacitors • Resistors Computer Concepts Parsons/Oja Page 62

Chapter 2 Section A Data Representation and Digital Electronics What’s a computer chip? • Chapter 2 Section A Data Representation and Digital Electronics What’s a computer chip? • Semiconducting materials are used to fabricate a chip • Types of chips • DIPs • DIMMs • PGAs • SEC cartridge Computer Concepts Parsons/Oja Pages 62 -63

Chapter 2 Section A Data Representation and Digital Electronics What’s a computer chip? DIP Chapter 2 Section A Data Representation and Digital Electronics What’s a computer chip? DIP DIMM PGA SEC Computer Concepts Parsons/Oja Page 63

Chapter 2 Section A Data Representation and Digital Electronics How do chips fit together Chapter 2 Section A Data Representation and Digital Electronics How do chips fit together to make a computer? • The motherboard houses all essential chips and provides connecting circuitry between them Computer Concepts Parsons/Oja Page 63

Chapter 2 Section A Data Representation and Digital Electronics How do chips fit together Chapter 2 Section A Data Representation and Digital Electronics How do chips fit together to make a computer? Expansion card DIMM module containing memory chips Connections for storage device cables Battery that powers the computer’s real-time clock Expansion slots hold additional expansion cards, such as a modem or sound card DIP holding a ROM chip Connector for power supply SEC-style microprocessor Computer Concepts Parsons/Oja Circuitry that transports data from one component to another Page 64

CHAPTER 2 Section B Microprocessors and Memory PARSONS/OJA Computer Hardware Computer Concepts Parsons/Oja Page CHAPTER 2 Section B Microprocessors and Memory PARSONS/OJA Computer Hardware Computer Concepts Parsons/Oja Page 66

Chapter 2 Section B Microprocessors and Memory Microprocessor Basics: Exactly what is a microprocessor? Chapter 2 Section B Microprocessors and Memory Microprocessor Basics: Exactly what is a microprocessor? • A microprocessor is an integrated circuit designed to process instructions • CPU on a chip Computer Concepts Parsons/Oja Page 66

Chapter 2 Section B Microprocessors and Memory What does a microprocessor look like? • Chapter 2 Section B Microprocessors and Memory What does a microprocessor look like? • The CPU has two parts • ALU (arithmetic logic unit) • Performs arithmetic operations • Performs logical operations • Uses registers to hold data being processed • The CPU’s control unit directs and coordinates processing. Computer Concepts Parsons/Oja Page 66

Chapter 2 Section B Microprocessors and Memory Where does the microprocessor get its instructions Chapter 2 Section B Microprocessors and Memory Where does the microprocessor get its instructions • The microprocessor executes instructions provided by a computer program • The list of instructions that a microprocessor can perform is called its instruction set Computer Concepts Parsons/Oja Page 67

Chapter 2 Section B Microprocessors and Memory Microprocessor Performance Factors: What makes one microprocessor Chapter 2 Section B Microprocessors and Memory Microprocessor Performance Factors: What makes one microprocessor perform better than another? • CPU speed is influenced by several factors: • Clock speed – Megahertz, Gigahertz • Word size • Cache – Level 1, Level 2 caches • instruction set size Computer Concepts Parsons/Oja Page 67 -68

Chapter 2 Section B Microprocessors and Memory What’s the difference between CISC and RISC? Chapter 2 Section B Microprocessors and Memory What’s the difference between CISC and RISC? • Computers based on a CPU with a complex instruction set known as CISC (complex instruction set computer) microprocessor • Intel • A RISC (reduced instruction set computer) has limited set of instructions that it can perform quickly • AMD Computer Concepts Parsons/Oja Page 68

Chapter 2 Section B Microprocessors and Memory Can a microprocessor execute more than one Chapter 2 Section B Microprocessors and Memory Can a microprocessor execute more than one instruction at a time? • Computers with a single processor execute instructions serially (one at a time) • Pipelining - technology in which the processor can begin executing the next instruction before it completes the previous instruction • A computer with more than one processor can execute multiple instructions simultaneously, referred to as parallel processing Computer Concepts Parsons/Oja Page 68

Chapter 2 Section B Microprocessors and Memory With so many factors to consider, how Chapter 2 Section B Microprocessors and Memory With so many factors to consider, how can I compare microprocessors? • Testing laboratories run a series of tests (benchmarks) to gauge the overall speed of a microprocessor • The results are published on the Web and in computer magazine articles • Benchmarks can be downloaded and run on home systems as well Computer Concepts Parsons/Oja Page 68

Chapter 2 Section B Microprocessors and Memory Today’s Microprocessors: Which companies produce most of Chapter 2 Section B Microprocessors and Memory Today’s Microprocessors: Which companies produce most of today’s popular microprocessors? • Intel • AMD (Advanced Micro Devices) • Motorola Computer Concepts Parsons/Oja Page 69

Chapter 2 Section B Microprocessors and Memory Which microprocessor is best for my computer? Chapter 2 Section B Microprocessors and Memory Which microprocessor is best for my computer? • AMD and Intel are comparable • Pentium 4 • Itanium • Celeron • Athlon • Opteron • Duron • The microprocessor that’s best for you depends upon your budget and the type of work and play you plan to do Computer Concepts Parsons/Oja Page 69

Chapter 2 Section B Microprocessors and Memory Can I replace my computer’s microprocessor with Chapter 2 Section B Microprocessors and Memory Can I replace my computer’s microprocessor with a faster one? • Technically yes, but most computer owners rarely do • Reasons not to upgrade • Cost • Technical factors – speed • Do research before you upgrade your microprocessor Computer Concepts Parsons/Oja Page 69

Chapter 2 Section B Microprocessors and Memory Random Access Memory: What is RAM? • Chapter 2 Section B Microprocessors and Memory Random Access Memory: What is RAM? • RAM (random access memory) - an area of the computer that temporarily holds data before and after it is processed • As you type, characters are held in RAM Computer Concepts Parsons/Oja Page 70

Chapter 2 Section B Microprocessors and Memory Why is RAM so important? • It Chapter 2 Section B Microprocessors and Memory Why is RAM so important? • It holds the data and the instructions for processing the data • It even houses OS instructions Computer Concepts Parsons/Oja Page 70

Chapter 2 Section B Microprocessors and Memory How does RAM differ from disk storage? Chapter 2 Section B Microprocessors and Memory How does RAM differ from disk storage? • Capacitors are microscopic electronic parts that hold the electronic signals for the code that represents data. • Charged capacitor = ON • Discharged capacitor = OFF • Each bank of capacitors holds eight bits • Disk storage is fairly permanent • Floppy disks, hard disks, CDs, DVDs • Volatile vs. Non-Volatile Computer Concepts Parsons/Oja Page 70 -71

Chapter 2 Section B Microprocessors and Memory How does RAM differ from disk storage? Chapter 2 Section B Microprocessors and Memory How does RAM differ from disk storage? • A RAM address on each bank helps the computer locate the data in that bank • RAM is a reusable computing source • RAM is volatile: requires power to hold data Computer Concepts Parsons/Oja Page 71

Chapter 2 Section B Microprocessors and Memory How does RAM differ from disk storage? Chapter 2 Section B Microprocessors and Memory How does RAM differ from disk storage? Computer Concepts Parsons/Oja Page 71

Chapter 2 Section B Microprocessors and Memory How much RAM does my computer need? Chapter 2 Section B Microprocessors and Memory How much RAM does my computer need? • RAM is primary storage (main memory) • Measured in megabytes (MB) or gigabytes (GB) • Today’s computers have between 128 MB and 2 GB of RAM • Depends on software you use • You can purchase additional RAM • A computer can use disk storage to simulate RAM. This is called virtual memory • Not as fast as RAM Computer Concepts Parsons/Oja Page 71

Chapter 2 Section B Microprocessors and Memory Do all computers use the same type Chapter 2 Section B Microprocessors and Memory Do all computers use the same type of RAM? • No. RAM components vary in speed, technology, and configuration • Speed is measured in nanoseconds. 1 nanosecond (ns) is 1 billionth of a second • It can also be expressed in MHz (millions of cycles per second) • SDRAM (Synchronous Dynamic RAM) • RDRAM (Rambus Dynamic RAM) Computer Concepts Parsons/Oja Page 72

Chapter 2 Section B Microprocessors and Memory Do all computers use the same type Chapter 2 Section B Microprocessors and Memory Do all computers use the same type of RAM? • RAM is usually configured as a series of DIPs soldered onto a small circuit board called a DIMM (dual in-line memory module), RIMM (Rambus inline memory module), or SO-RIMM (small outline RIMM) • DIMMs contain SDRAM, RIMMs and SO-RIMMs contain RDRAM SDRAM chip Computer Concepts Parsons/Oja Page 72

Chapter 2 Section B Microprocessors and Memory Read-Only Memory: How is ROM different from Chapter 2 Section B Microprocessors and Memory Read-Only Memory: How is ROM different from RAM? • ROM (read-only memory) is one or more chips containing instructions that help a computer prepare to process tasks • ROM is permanent and non-volatile • Only way to change the instructions on a ROM chip is to replace the chip Computer Concepts Parsons/Oja Page 72

Chapter 2 Section B Microprocessors and Memory If a computer has RAM, why does Chapter 2 Section B Microprocessors and Memory If a computer has RAM, why does it need ROM too? • Since RAM is empty when a computer is turned on, ROM BIOS is used • ROM BIOS (basic input/output system) is a set of instructions that tells computer how to access the disk drives and peripheral devices • Once operating system is loaded, the computer can understand your input, run software and access your data Computer Concepts Parsons/Oja Page 72

Chapter 2 Section B Microprocessors and Memory CMOS memory: Where does a computer store Chapter 2 Section B Microprocessors and Memory CMOS memory: Where does a computer store its basic hardware settings? • A computer needs a semi-permanent way of keeping boot data, such as the number of hard disk sectors and cylinders • CMOS memory - holds data but requires very little power to retain its contents • Retains important computer settings after you turn the power off • Can run by a battery on the motherboard • Housed within the same chip carrier as ROM BIOS Computer Concepts Parsons/Oja Page 73

Chapter 2 Section B Microprocessors and Memory Where does a computer store its basic Chapter 2 Section B Microprocessors and Memory Where does a computer store its basic hardware settings? Computer Concepts Parsons/Oja Page 73

Chapter 2 Section B Microprocessors and Memory What’s the most important information about memory Chapter 2 Section B Microprocessors and Memory What’s the most important information about memory provided by computer ads? • Most ads specify RAM capacity, speed and type • 1 GB 8 ns RDRAM (max. 2 GB) Computer Concepts Parsons/Oja Page 74

CHAPTER Section C Storage Devices 2 PARSONS/OJA Computer Hardware Computer Concepts Parsons/Oja Page 76 CHAPTER Section C Storage Devices 2 PARSONS/OJA Computer Hardware Computer Concepts Parsons/Oja Page 76

Chapter Section C Storage Devices 2 Storage Basics: What are the basic components of Chapter Section C Storage Devices 2 Storage Basics: What are the basic components of a data storage system? • A storage device, such as a floppy disk drive, a hard drive, zip drive, and a CD-ROM drive, is used to store the data • A storage medium is the disk, tape, CD, DVD, paper or other substance that contains data Computer Concepts Parsons/Oja Page 76

Chapter Section C Storage Devices 2 How does a storage system interact with other Chapter Section C Storage Devices 2 How does a storage system interact with other computer components? • Storing - also known as • Writing data • Saving a file • Retrieving - also known as • Reading data • Loading data • Opening a file Computer Concepts Parsons/Oja Page 76

Chapter Section C Storage Devices 2 What’s the difference between magnetic and optical storage Chapter Section C Storage Devices 2 What’s the difference between magnetic and optical storage technologies? • Magnetic storage - stores data by magnetizing microscopic particles on the disk or tape surface • Read-write head - mechanism in the disk drive that reads and writes magnetized particles that represent data Computer Concepts Parsons/Oja Page 77

Chapter Section C Storage Devices 2 What’s the difference between magnetic and optical storage Chapter Section C Storage Devices 2 What’s the difference between magnetic and optical storage technologies? Computer Concepts Parsons/Oja Page 77

Chapter Section C Storage Devices 2 What’s the difference between magnetic and optical storage Chapter Section C Storage Devices 2 What’s the difference between magnetic and optical storage technologies? • Data stored on magnetic media such as floppy disks can be altered by dust, smoke, heat, and mechanical problems. • Some experts estimate that the reliable life span of data stored on magnetic media is about three years Computer Concepts Parsons/Oja Page 77

Chapter Section C Storage Devices 2 What’s the difference between magnetic and optical storage Chapter Section C Storage Devices 2 What’s the difference between magnetic and optical storage technologies? • Optical storage stores data as microscopic light spots (lands) and dark spots (pits) on the disk surface • Data stored on an optical storage device is more susceptible to environmental damage Computer Concepts Parsons/Oja Page 78

Chapter Section C Storage Devices 2 What’s the difference between magnetic and optical storage Chapter Section C Storage Devices 2 What’s the difference between magnetic and optical storage technologies? CD-ROM: PITS Computer Concepts Parsons/Oja Page 78

Section C Storage Devices Chapter 2 Can I add storage devices to my computer? Section C Storage Devices Chapter 2 Can I add storage devices to my computer? • Devices can be added into empty drive bays An empty 5 1/4” drive bay located on the front of a desktop computer An empty 3 1/2” drive bay Click to start Computer Concepts Parsons/Oja An empty drive bay located on the side of a notebook computer Page 78

Chapter Section C Storage Devices 2 Which storage technology is best? • Versatility • Chapter Section C Storage Devices 2 Which storage technology is best? • Versatility • Can access data from different media • Durability • Less susceptible to damage • Storage capacity - maximum amount of data that can be stored on a storage medium Computer Concepts Parsons/Oja Page 79

Chapter Section C Storage Devices 2 Which storage technology is best? • Speed - Chapter Section C Storage Devices 2 Which storage technology is best? • Speed - measured by access time and data transfer rate • Access time - average time it takes a computer to locate data and read it • millisecond = one-thousandth of a second • Random access - ability of a device to jump directly to the track or sector holding the data • floppy disk, hard drive, CD, DVD, zip disks Computer Concepts Parsons/Oja Page 79

Chapter Section C Storage Devices 2 Floppy disk Technology: Why is it called a Chapter Section C Storage Devices 2 Floppy disk Technology: Why is it called a “floppy disk”? • A floppy disk is a round piece of flexible mylar plastic covered with a thin layer of magnetic oxide and sealed inside a protective casing Computer Concepts Parsons/Oja Page 79

Section C Storage Devices Chapter 2 What’s the capacity of a floppy disk? • Section C Storage Devices Chapter 2 What’s the capacity of a floppy disk? • 3 ½ diskettes have capacity of 1. 44 MB • Other floppy disk types • ZIP disks – 100 MB, 250 MB, and 750 MB • Superdisks – 120 MB or 240 MB Superdisk ZIP disk Computer Concepts Parsons/Oja Page 80

Chapter Section C Storage Devices 2 How can ZIP disks and Superdisks store so Chapter Section C Storage Devices 2 How can ZIP disks and Superdisks store so much more data than standard floppy on the same size disk? • Disk density - closeness and size of magnetic particles it stores • Zip disks and Superdisks store data at a higher density than a standard 3 ½ floppy disk Computer Concepts Parsons/Oja Page 80

Chapter Section C Storage Devices 2 What does “HD DS” mean? • High-density disk Chapter Section C Storage Devices 2 What does “HD DS” mean? • High-density disk - stores more data than double-density • Double-sided disk - stores twice as much as single-sided Computer Concepts Parsons/Oja Page 80

Chapter Section C Storage Devices 2 What are the advantages and disadvantages of floppy Chapter Section C Storage Devices 2 What are the advantages and disadvantages of floppy disk technology? • Major advantage – portability • Major disadvantage – not a particularly speedy device and limited storage capacity • Today most software vendors use CD-ROM or DVD-ROM disks instead Computer Concepts Parsons/Oja Page 80 -81

Chapter Section C Storage Devices 2 Can I protect the data on a floppy Chapter Section C Storage Devices 2 Can I protect the data on a floppy disk? • The write-protect window allows you to protect data by making it read-only when it is open, but to modify the storage data, it must be closed Write-protect window Computer Concepts Parsons/Oja Page 81

Chapter Section C Storage Devices 2 Hard Disk Technology: Why are hard disk drives Chapter Section C Storage Devices 2 Hard Disk Technology: Why are hard disk drives so popular? • It provides lots of storage capacity • It provides faster access to files than floppy disk drives • It is economical Computer Concepts Parsons/Oja Page 81

Chapter Section C Storage Devices 2 How does a hard disk work? • Hard Chapter Section C Storage Devices 2 How does a hard disk work? • Hard disk platter - a flat, rigid disk made of aluminum or glass and coated with magnetic oxide • Density far exceeds floppy disk • Hard disk - one or more platters and their associated read-write heads. • Preferred type of main storage Computer Concepts Parsons/Oja Page 81

Chapter Section C Storage Devices 2 How does a hard disk work? The drive Chapter Section C Storage Devices 2 How does a hard disk work? The drive spindle supports one or more hard disk platters. Both sides of the platter are used for data storage. More platters mean more data storage capacity. Hard disk platters rotate as a unit on the spindle to position read-write heads over the specific data. The platters spin continuously making thousands of rotations per minute. Click to start Computer Concepts Parsons/Oja Each data storage surface has its own readwrite head, which moves in and out from the center of the disk to locate data. The head hovers only a few microinches above the disk surface, so the magnetic field is much more compact than on a floppy disk. As a result, more data is packed into a smaller area on a hard disk platter. Page 82

Chapter Section C Storage Devices 2 What’s all this business about Ultra ATA, EIDE, Chapter Section C Storage Devices 2 What’s all this business about Ultra ATA, EIDE, SCSI, and DMA? • A hard drive mechanism includes a circuit board called a controller that positions the disk and read-write heads to locate data • Popular drives • Ultra ATA (AT attachment) • EIDE (enhanced integrated drive electronics) • SCSI (small computer system interface) Computer Concepts Parsons/Oja Page 82

Chapter Section C Storage Devices 2 What’s all this business about Ultra ATA, EIDE, Chapter Section C Storage Devices 2 What’s all this business about Ultra ATA, EIDE, SCSI, and DMA? • DMA (direct memory access) technology allows a computer to transfer data directly from a drive into RAM without intervention from the processor • UDMA (ultra DMA) is a faster version of DMA technology Computer Concepts Parsons/Oja Page 82

Chapter Section C Storage Devices 2 What’s the downside of hard disk storage? • Chapter Section C Storage Devices 2 What’s the downside of hard disk storage? • Head crash - when a read-write head runs into a dust particle or other contaminant on the disk • Head crash damages some data on disk • Triggered by jarring the hard disk while in use • Not limited to hard disks Computer Concepts Parsons/Oja Page 83

Chapter Section C Storage Devices 2 Can I use a second hard disk drive Chapter Section C Storage Devices 2 Can I use a second hard disk drive as a backup? • Removable hard disk - hard disks that can be inserted and removed from drive • Increase storage capacity • Provides security for data • RAID - (redundant array of independent disks) • Type of hard disk storage • Found on mainframe and microcomputer installations • Contains many disk platters • Provides redundancy • Faster data access Computer Concepts Parsons/Oja Page 83

Chapter Section C Storage Devices 2 Tape Storage: What’s the purpose of a tape Chapter Section C Storage Devices 2 Tape Storage: What’s the purpose of a tape drive? • Tape • Most popular form of storage in 1960 s • Recent revival in tape storage for backing up data, not for principal storage device. • Tape backup - copy of data on hard disk stored on magnetic tape. Computer Concepts Parsons/Oja Page 83

Chapter Section C Storage Devices 2 How does a tape drive work? • Sequential Chapter Section C Storage Devices 2 How does a tape drive work? • Sequential access • Inconvenient and slow • Data is arranged as a long sequence of bits that begin at one end of the tape and stretches to the other • Has a directory at the beginning or end of the tape that catalogs contents Computer Concepts Parsons/Oja Page 83

Chapter Section C Storage Devices 2 Is it easy to install a tape drive? Chapter Section C Storage Devices 2 Is it easy to install a tape drive? • Yes. Tape drives are available in either internal or external models Computer Concepts Parsons/Oja Page 84

Chapter Section C Storage Devices 2 CD technology: Why would I want a CD-ROM Chapter Section C Storage Devices 2 CD technology: Why would I want a CD-ROM drive in addition to a hard disk drive? • CD-ROM • Stands for Compact Disc Read-Only Memory • Data stamped on when manufactured • Coated with clear plastic, durable • Estimated life exceeds 500 years • Inexpensive to manufacture • Ideal for distribution of large files Computer Concepts Parsons/Oja Page 84

Chapter Section C Storage Devices 2 What’s the capacity and speed of a CD? Chapter Section C Storage Devices 2 What’s the capacity and speed of a CD? • A single CD-ROM holds up to 650 MB • It is very durable if handled carefully • Original CD-ROM had speeds of 150 KB per second • Today, speeds of 24 x or higher (24 x 150 KB per second) • Newer models should be over 50 x Computer Concepts Parsons/Oja Page 85

Chapter Section C Storage Devices 2 What’s the difference between CD-ROM and ROM BIOS? Chapter Section C Storage Devices 2 What’s the difference between CD-ROM and ROM BIOS? • They are different technologies • ROM-BIOS (chip on the motherboard) is magnetic • CD-ROM (optical storage device) is optical Computer Concepts Parsons/Oja Page 85

Chapter Section C Storage Devices 2 What’s the difference between CDROM and ROM BIOS? Chapter Section C Storage Devices 2 What’s the difference between CDROM and ROM BIOS? Laser lens directs a beam of light to the underside of the CD-ROM disk Drive spindle spins disk Laser pickup assembly senses the reflectivity of pits and lands Tracking mechanism positions a disk track over the laser lens Computer Concepts Parsons/Oja Page 85

Chapter Section C Storage Devices 2 Can I create my own CDs? • CD-R Chapter Section C Storage Devices 2 Can I create my own CDs? • CD-R • Stands for compact disc-recordable • Allows you to create your own CDs by recording on a CD-R disk • Recording is done on a CD-R drive • Uses a laser to change the reflectivity of a dye layer on a blank CD-R disk • Can be read by standard CD-ROM or DVD drive Computer Concepts Parsons/Oja Page 85

Chapter Section C Storage Devices 2 Can I create my own CDs? • CD-RW Chapter Section C Storage Devices 2 Can I create my own CDs? • CD-RW (compact disc-rewritable) allows you to write on a CD, then change the data • Requires special CD-RW disks • Requires special CD-RW drive • Requires phase change technology • Phase change technology - alters the crystal structure on the disk surface Computer Concepts Parsons/Oja Page 86

Chapter Section C Storage Devices 2 Is CD-RW a viable replacement for a hard Chapter Section C Storage Devices 2 Is CD-RW a viable replacement for a hard disk? • It is slower than hard disk access; therefore not a suitable replacement yet • Archiving - moving data that is not accessed frequently off of a primary storage device Computer Concepts Parsons/Oja Page 86

Chapter Section C Storage Devices 2 DVD Technology: How is DVD different from CD Chapter Section C Storage Devices 2 DVD Technology: How is DVD different from CD technology? • DVD (digital video disc or digital versatile disc) • Variation of CD technology • Designed to provide enough storage capacity for a full length movie • Will replace video tape (experts believe) • DVD-ROM disk (sometimes used for DVD-Video) • Stamped with data when manufactured • Cannot change or add data • Stores 4. 7 GB • Ideal for games, maps, large databases Computer Concepts Parsons/Oja Page 86

Chapter Section C Storage Devices 2 DVD Technology: How is DVD different from CD Chapter Section C Storage Devices 2 DVD Technology: How is DVD different from CD technology? Computer Concepts Parsons/Oja Page 86

Chapter Section C Storage Devices 2 Is my computer DVD drive the same as Chapter Section C Storage Devices 2 Is my computer DVD drive the same as the one that’s connected to my television set? • Not exactly. Movie files are still very large. Television DVD drives include MPEG decoding circuitry • Most movie DVDs are encoded in MPEG-2 data coding format Computer Concepts Parsons/Oja Page 87

Chapter Section C Storage Devices 2 Are CDs and DVDs interchangeable? • CD-ROM drives Chapter Section C Storage Devices 2 Are CDs and DVDs interchangeable? • CD-ROM drives can not play DVDs • DVDs can play CD-ROM, most CD-R and most CD-RW disks Computer Concepts Parsons/Oja Page 87

Chapter Section C Storage Devices 2 Is there a DVD equivalent to CD-RW? • Chapter Section C Storage Devices 2 Is there a DVD equivalent to CD-RW? • DVD+RW • Uses phase change technology • Cannot be used on DVD-RAM • Uses a blend of technologies to record data • Cannot be used on DVD+RW • Both DVD+RW and DVD-RAM can be read on DVD-ROM drives • There is also DVD-R Computer Concepts Parsons/Oja Page 87

CHAPTER Section D Input and Output Devices 2 PARSONS/OJA Computer Hardware Computer Concepts Parsons/Oja CHAPTER Section D Input and Output Devices 2 PARSONS/OJA Computer Hardware Computer Concepts Parsons/Oja Page 88

Chapter Section D Input and Output Devices 2 Expansion slots, cards and ports: How Chapter Section D Input and Output Devices 2 Expansion slots, cards and ports: How does a computer get data from RAM to a peripheral device? • Data Bus carries data from one component to another • I/O (computer jargon for input/output) refers to collecting data and transporting results. • Expansion bus - the segment of the data bus that transports data between RAM and peripheral devices Computer Concepts Parsons/Oja Page 88

Chapter Section D Input and Output Devices 2 What is an expansion slot? • Chapter Section D Input and Output Devices 2 What is an expansion slot? • Expansion slot - long, narrow socket on the motherboard into which you can plug an expansion card • Graphics card (for connecting monitor) • Modem (for transmitting data over phone or cable lines) • Sound card (for connecting speakers) • Expansion card - small circuit board that provides computer with ability to control storage, input or output device • Most computers have 4 - 8 expansion slots Computer Concepts Parsons/Oja Page 88 -89

Chapter Section D Input and Output Devices 2 What is an expansion slot? Click Chapter Section D Input and Output Devices 2 What is an expansion slot? Click to start Computer Concepts Parsons/Oja Page 88

Chapter Section D Input and Output Devices 2 What are the major types of Chapter Section D Input and Output Devices 2 What are the major types of expansion slots? • The microcomputer motherboard typically has up to three types of expansion slots: • ISA - older technology, modems and slow devices • PCI - for graphics, sound, video, modem or network cards • AGP - for graphics cards • Expansion cards are built for only one type of slot Computer Concepts Parsons/Oja Page 89

Chapter Section D Input and Output Devices 2 What are the major types of Chapter Section D Input and Output Devices 2 What are the major types of expansion slots? AGP slot ISA slot PCI slot Computer Concepts Parsons/Oja Page 89

Chapter Section D Input and Output Devices 2 Do notebook computers also contain expansion Chapter Section D Input and Output Devices 2 Do notebook computers also contain expansion slots? • Most notebook computers are equipped with a special type of external slot called a PCMCIA slot (personal computer memory card international association) • Typically a notebook only has one slot, but the slot can hold more than one PC card (PCMCIA expansion cards) Computer Concepts Parsons/Oja Page 90

Chapter Section D Input and Output Devices 2 Do notebook computers also contain expansion Chapter Section D Input and Output Devices 2 Do notebook computers also contain expansion slots? PC card Computer Concepts Parsons/Oja Page 90

Chapter Section D Input and Output Devices 2 What is an expansion port? • Chapter Section D Input and Output Devices 2 What is an expansion port? • To connect a peripheral device to an expansion card, you plug a cable from the device into the expansion port • Expansion port - any connector that passes data in and out of a computer or peripheral device Computer Concepts Parsons/Oja Page 90

Chapter Section D Input and Output Devices 2 What is an expansion port? Power Chapter Section D Input and Output Devices 2 What is an expansion port? Power plug socket Keyboard port Mouse port USB ports DB-9 serial port Parallel port (printer) Speaker and microphone jacks Monitor port Modem port Network port Computer Concepts Parsons/Oja Page 90

Chapter Section D Input and Output Devices 2 What are the major types of Chapter Section D Input and Output Devices 2 What are the major types of expansion cables? Computer Concepts Parsons/Oja Page 90 -91

Chapter Section D Input and Output Devices 2 What’s the best port to use Chapter Section D Input and Output Devices 2 What’s the best port to use for connecting peripheral devices? • USB port • Most popular port • Most computers feature at least 2 USB ports • USB devices • • Mouse Scanner Printer Joystick • Windows automatically recognizes USB devices Computer Concepts Parsons/Oja Page 91

Chapter Section D Input and Output Devices 2 Installing Peripheral Devices: Is it difficult Chapter Section D Input and Output Devices 2 Installing Peripheral Devices: Is it difficult to install a new peripheral device? • Internal devices • Tools required • Screwdriver • Directions • Before installing • Unplug the computer • Ground yourself • Installing • Follow the directions Computer Concepts Parsons/Oja Page 92

Chapter Section D Input and Output Devices 2 Why do some peripheral devices include Chapter Section D Input and Output Devices 2 Why do some peripheral devices include a disk or CD? • Some devices require software, called a device driver • The device driver sets up communication between your computer and the device • Normally, disk or CD used only once • Today’s PCs include Plug and Play (Pn. P) that automatically takes care of these technical details Computer Concepts Parsons/Oja Page 92

Chapter Section D Input and Output Devices 2 Display devices: What are the components Chapter Section D Input and Output Devices 2 Display devices: What are the components of a typical computer display system? • A Graphics card takes signals from the processor and uses them to “paint” images on the screen • Installed inside computer • Provides connection for monitor’s data cable • A fast processor can handle huge amounts of digital data quickly • Fit into an AGP expansion slot • PCI cards take longer to update the screen Computer Concepts Parsons/Oja Page 92

Chapter Section D Input and Output Devices 2 What’s the difference between a CRT Chapter Section D Input and Output Devices 2 What’s the difference between a CRT and an LCD? • CRT (cathode ray tube) uses gun-like mechanisms to direct beams of electrons toward the screen and activate individual dots of color that form an image • LCD (liquid crystal display) produces an image by manipulating light within a layer of crystal cells • LCDs are clearer, have low radiation emission, are portable, and compact • LCDs are also more expensive than CRTs Computer Concepts Parsons/Oja Page 92

Chapter Section D Input and Output Devices 2 Which display device produces the best Chapter Section D Input and Output Devices 2 Which display device produces the best image? • Screen size is the measurement in inches from one corner of the screen diagonally across to the opposite corner. • Viewable image size (vis) - black border that makes image size smaller than size specified • Dot pitch - a measure of image clarity • Smaller dot pitch means a crisper image • Resolution - number of pixels a monitor can display • Rows x Columns Computer Concepts Parsons/Oja Page 93

Chapter Section D Input and Output Devices 2 Which display device produces the best Chapter Section D Input and Output Devices 2 Which display device produces the best image? Two different resolutions Computer Concepts Parsons/Oja Page 93

Chapter Section D Input and Output Devices 2 Which display device produces the best Chapter Section D Input and Output Devices 2 Which display device produces the best image? • Color depth - number of colors that can be displayed at one time • Passive matrix screen - relies on timing to make sure the liquid crystal cells are illuminated • Active matrix screen - updates rapidly • Essential for crisp display of animation, video • Found on newer notebooks • SVGA - (Super video graphics array) = 800 x 600 • XGA - (e. Xtended graphics array) = 1024 x 768 • SXGA - (Super XGA) = 1280 x 1024 • UXGA - (Ultra XGA) = 1600 x 1200 Computer Concepts Parsons/Oja Page 94

Chapter Section D Input and Output Devices 2 Printers: What features should I look Chapter Section D Input and Output Devices 2 Printers: What features should I look for in a printer? • Resolution • Printer resolution is measured in dpi (dots per inch), the number of dots it can print per linear inch. • Come in color or black and white Computer Concepts Parsons/Oja Page 94

Chapter Section D Input and Output Devices 2 What features should I look for Chapter Section D Input and Output Devices 2 What features should I look for in a printer? • Print speed • Measured either by pages per minute (ppm) or characters per second (cps) • Color takes longer than black and white • Text prints faster than graphics • Ten pages per minute (black and white) = typical speed for today’s jet and laser printers Computer Concepts Parsons/Oja Page 94

Chapter Section D Input and Output Devices 2 What features should I look for Chapter Section D Input and Output Devices 2 What features should I look for in a printer? • Printer cost • Printers for microcomputers range from $100 to $5000 • Duty cycle - indication of the number of pages a printer can be expected to print per month • Indicates maintenance costs • Per-copy cost • Printers require ongoing costs including ribbons, ink cartridges, and toner • Per copy cost is the cost of printing a page with an average amount of text, graphics, and color • Warranty • Cover mechanical problems Computer Concepts Parsons/Oja Page 94 -95

Chapter Section D Input and Output Devices 2 What features should I look for Chapter Section D Input and Output Devices 2 What features should I look for in a printer? Lexmark Printer Computer Concepts Parsons/Oja Page 95

Chapter Section D Input and Output Devices 2 What’s the difference between an ink Chapter Section D Input and Output Devices 2 What’s the difference between an ink jet printer and a solid ink printer? • A solid ink printer melts sticks of crayon-like ink and then sprays the liquefied ink through the print head’s tiny nozzles and produces vibrant color on any paper • An ink jet printer is today’s most popular printing technology. • Print head consists of a series of nozzles that sprays ink onto paper • On special paper can produce photographic quality Computer Concepts Parsons/Oja Page 95

Chapter Section D Input and Output Devices 2 What about thermal wax transfer and Chapter Section D Input and Output Devices 2 What about thermal wax transfer and dye sublimation printers? • Thermal transfer printer • Uses page-sized ribbons coated with wax • Print head consists of heating elements to melt the wax • Dye sublimation printer • Similar to wax, but page-sized ribbon contains dye • Print heads diffuse the dye Computer Concepts Parsons/Oja Page 95

Chapter Section D Input and Output Devices 2 Is a laser better than an Chapter Section D Input and Output Devices 2 Is a laser better than an ink jet? • A laser printer uses the same technology as a photocopier to paint dots of light on a lightsensitive drum. • Higher quality than ink jet • More expensive to buy than ink jet • Less expensive to operate than ink jet Computer Concepts Parsons/Oja Page 95

Chapter Section D Input and Output Devices 2 Is a laser better than an Chapter Section D Input and Output Devices 2 Is a laser better than an ink jet? • Laser printers use their own printer language to construct a page before printing it. • Printer Control Language (PCL) - most widely used • Post. Script language - preferred by publishing professionals • Printer languages require 2 MB - 8 MB memory Computer Concepts Parsons/Oja Page 96

Section D Input and Output Devices Chapter 2 Is a laser better than an Section D Input and Output Devices Chapter 2 Is a laser better than an ink jet? Laser. Jet Click to start Computer Concepts Parsons/Oja Page 96

Chapter Section D Input and Output Devices 2 Why would anyone want a dot Chapter Section D Input and Output Devices 2 Why would anyone want a dot matrix printer? • Dot matrix printers produce characters and graphics by using a grid of fine wires • Introduced in 1970 s • Low quality output • Used for “back-office” applications that demand low operating cost and dependability • Can print multipart carbon forms • $4 ribbon can print 3 million characters Computer Concepts Parsons/Oja Page 96

Chapter Section D Input and Output Devices 2 Why would anyone want a dot Chapter Section D Input and Output Devices 2 Why would anyone want a dot matrix printer? Print head contains a matrix of thin wires Characters are formed from a pattern of dots Computer Concepts Parsons/Oja Page 96

Chapter Section D Input and Output Devices 2 Is it easy to install a Chapter Section D Input and Output Devices 2 Is it easy to install a printer? • Uses a cable to connect to one of your computer’s ports • USB • Parallel • Serial • Many come packaged with device driver software that you install following manufacturer’s direction • Can be set to default printer using windows software Computer Concepts Parsons/Oja Page 97

Chapter Section D Input and Output Devices 2 Is it easy to install a Chapter Section D Input and Output Devices 2 Is it easy to install a printer? Printers Control Window Click to start Computer Concepts Parsons/Oja Page 97