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Overview of Computer Hardware CS 1 Introduction to Computers and Computer Technology Rick Graziani Fall 2006 Hardware Components INPUT Know these! Rick Graziani [email protected] SYSTEM UNIT OUTPUT PERMANENT STORAGE 2 The System Unit Let’s open the box! Rick Graziani [email protected] 3 The System Unit circuit board = a board with integrated circuits (microchips) • system board or motherboard • interface boards or expansion boards system board or motherboard = a single circuit board with the components which make up the computer’s processor for a microcomputer, including the: • CPU (Central Processing Unit) • Memory – RAM – ROM or ROM BIOS • Rickexpansion slots Graziani [email protected] 4 Rick Graziani [email protected] 5 Rick Graziani [email protected] 6 The System Unit circuit board = a board with integrated circuits (microchips) • system board or motherboard • interface boards or expansion boards Rick Graziani [email protected] 7 The System Unit system board or motherboard = a single circuit board with the components which make up the computer’s processor for a microcomputer, including the: • CPU (Central Processing Unit) • RAM • ROM or ROM BIOS • expansion slots Rick Graziani [email protected] 8 The System Unit Interface board/card (or Expansion board/card)- used to connect peripheral devices (monitor, printer, etc.) to the motherboard (more on this “later”) Rick Graziani [email protected] 9 The System Unit Rick Graziani [email protected] 10 The System Unit Inserting an Interface card or Expansion board into an expansion slot of the motherboard Rick Graziani [email protected] 11 The System Unit • • • Integrated Circuits (microchips) What can they do? 1. Store bits: store the data and instructions used for processing Example: RAM and ROM chips (later) 2. Process bits: process the data and instructions Example: CPU (next) Rick Graziani [email protected] 12 The CPU- The Real Computer CPU (Central Processing Unit)= A complex collection of electronic circuits on one or more integrated circuits (chips) which: 1. executes the instructions in a software program 2. communicates with other parts of the computer system, especially RAM The CPU is the computer! Rick Graziani [email protected] 13 Some of the parts of the CPU Arithmetic Logic Unit (ALU) = area of the CPU responsible for the actual processing “The CPU’s calculator” Control Unit (CU) = area of the CPU responsible for getting data and instructions from RAM Rick Graziani [email protected] 14 What is in charge of the CPU? The operating system software! The “OS” Windows XP, Macintosh OS, Linux/UNIX, etc. The operating system manages what programs and data the CPU will be working on. More Later on Operating Sys.! Rick Graziani [email protected] 15 A CPU can be: A CPU can be: 1. A series of integrated circuits (chips) on one or more circuit boards – Older mainframe and minicomputers 2. On a single integrated circuit known as a microprocessor microprocessor = a CPU on a single chip microcomputer = older term for a computer with a microprocessor(s) (PC, Macintosh) Rick Graziani [email protected] 16 The Microprocessor (again) Rick Graziani [email protected] 17 The Microprocessor Compatibility Why can’t I run Windows software on my Macintosh and visa versa? • Operating system software is designed to run on one specific type of CPU or “family of CPUs” • Application software is designed to work with a specific operating system software, thus one specific type of CPU or “family of CPUs” More “later” Rick Graziani [email protected] 18 RAM- Primary Memory RAM (Random Access Memory) = integrated circuits (chips) used to temporarily store software (programs, instructions) and data • “primary” storage for the CPU • electronic switches, storing ON’s and OFF’s Rick Graziani [email protected] 19 RAM – Primary Memory (storage) Temporarily stores for the CPU: Software • operating system software • application software Rick Graziani [email protected] Data • documents, spreadsheets, etc. 20 RAM Rick Graziani [email protected] 21 Inserting RAM onto the motherboard Rick Graziani [email protected] 22 RAM - Volatile RAM is TEMPORARY memory RAM is volatile • stores ON and OFF bits (software and data) electrically • when power goes off, everything in RAM is lost Rick Graziani [email protected] 23 RAM - Speed Why does the CPU use RAM? • The CPU is very FAST! • The CPU needs the instructions (software) and data as quickly as possible • If the CPU has to wait, so does the user Why doesn’t the CPU use permanent storage like disk drives? • Too slow • EXAMPLE: Spellchecker Rick Graziani [email protected] 24 RAM - Capacity The amount of RAM determines: • What software and data the user can work on • how much software and data the user can work with “Not enough memory” error message from the Operating System • The more complex and sophisticated the software, the more instructions that software contains, which means larger software files. Rick Graziani [email protected] 25 RAM - Capacity Rick Graziani [email protected] 26 RAM – Temporary Storage If RAM is temporary where is the data and software stored permanently? Permanent storage devices such as: • hard disk drives • floppy disks • CD ROM disk • Flash sticks (“later”) Rick Graziani [email protected] 27 Example: Typing a document in Microsoft Works In RAM memory • MS (Microsoft) Windows XP operating system or Macintosh OS • MS Words • the document What the user sees on the screen is being stored in RAM Rick Graziani [email protected] 28 CPU RAM ROM 256 MB Hard Disk Drive Operating System Software “The kernel” Application Software MS Word User data (information) 0 Rick Graziani [email protected] 29 ROM - Read Only Memory ROM (Read Only Memory) = integrated circuits (microchips) that are used to permanently store start-up (boot) instructions and other critical information Read Only = information which: • cannot be changed • cannot be removed • cannot be appended (added to) Rick Graziani [email protected] 30 ROM - Read Only Memory ROM is sometimes known as ROM BIOS (Basic Input Output System software) ROM permanently contains: • start-up (boot) instructions • instructions to do “low level” processing of input and output devices, such as the communications with the keyboard and the monitor Rick Graziani [email protected] 31 ROM - Read Only Memory Firmware = software program which is stored permanently on a microchip, such as the software on the ROM chip Rick Graziani [email protected] 32 Booting up the computer Booting the computer = starting the computer Four phase of the boot process: S.P.I.T. 1. System Start-up 2. Power On Self-Test (POST) 3. Initialization 4. Transfer to the operating system software Rick Graziani [email protected] 33 1. System Start-up • • • • Turning on the computer Power supply supplies electricity to the computer The ROM chip boot instructions (firmware) is now “in charge” ROM chip instructions processed by the CPU Rick Graziani [email protected] 34 2. Power On Self-Test The ROM chip boot instructions tests the “processor” including: • checks the CPU • tests RAM memory and calculates it’s capacity • checks other components on the motherboard Rick Graziani [email protected] 35 3. Initialization The ROM chip boot instructions checks the “peripheral devices” including: Input devices • keyboard, mouse Output devices • monitor, printer Storage devices • hard disk • floppy drives • CD ROM drive Rick Graziani [email protected] 36 What is a peripheral device? A device which is connected to the computer’s processor, including input, output, and storage devices. (More later) Rick Graziani [email protected] 37 4. Transfer to an operating system software • The ROM chip boot instructions are now finished • The ROM chip wants to give control over to an operating system • software The ROM chip searches for the operating system (usually on the hard disk drive) and transfers an operating system file (the kernel) into RAM memory Rick Graziani [email protected] 38 Booted up The operating system software is now in charge! • The operating system file, known as the kernel, is in RAM memory • The user may now access application programs and data (double click on MS Word) • The operating system software is in charge (More later) Rick Graziani [email protected] 39 Inside the CPU The CPU Rick Graziani [email protected] 41 CPU • The CPU is the brains of the computer. • The CPU is the computer! • The CPU decision is the most important decision you will need to make • in purchasing a computer. Operating system software and application software requires a minimum type of CPU (don’t limit yourself in your purchase) Rick Graziani [email protected] 42 The Operating System Software and the CPU • OS manages the CPU • OS manages what the CPU will work on and when • The user can only take advantage of the complete abilities of the CPU only if the operating system software and application software also have those abilities. Rick Graziani [email protected] 43 Tighter Circuitry • Closer the circuits are together, the more circuits that can fit on a • • single chip Faster performance when there are fewer chips Moore’s Law: Gordon Moore, chairman of the board of Intel in the 1960’s stated that transistor densities on a single chip would double every 18 months Rick Graziani [email protected] 44 Power of the CPU 1. The number of bits processed 2. The size of the CPUs data bus 3. The Speed of the CPU 4. Internal Cache Rick Graziani [email protected] 45 1. The number of bits processed Toll Booth Analogy Rick Graziani [email protected] 46 1. The number of bits processed Early microprocessors: • 4 bit and 8 bit processors • Intel 8088, 80286: 16 bit processors • Intel 80386, 80486, Pentium: 32 bit processors • Motorola (Apple) 68020, 30, 40 and the PowerPC: 32 bit processors Current processors • 32 bit processors Latest: • 64 & 128 bit processors Rick Graziani [email protected] 47 Pentium III Rick Graziani [email protected] 48 Pentium 4 Rick Graziani [email protected] 49 AMD Processors (continued) Rick Graziani [email protected] 50 VIA C3 Processor Rick Graziani [email protected] 51 64-Bit Processors • Intel Itaniums • AMD 64-bit processors Rick Graziani [email protected] 52 The Itanium 2 Processor Rick Graziani [email protected] 53 AMD 64-Bit Processors Rick Graziani [email protected] 54 CPU Heat Sinks and Cooling Fans Rick Graziani [email protected] 55 Combination Heat Sink and Cooling Fan Rick Graziani [email protected] 56 2. The CPU’s Data Bus • Toll Booth Rick Graziani [email protected] 57 2. The CPU’s Data Bus Data bus = the number or wires between the CPU and RAM More wires (lanes) the faster the CPU gets the data and software to process Older CPUs: 8 and 16 bit data bus Newer CPUs: 32 and 64 bit data bus Rick Graziani [email protected] 58 The OS also plays a part! Amount of RAM recognized by the Operating System • Windows 95: 1GB • Windows 98: 1GB • Windows 98SE: 1GB • Windows ME: 1.5GB • Windows NT: 4GB • Windows 2000 Professional: 4GB • Windows XP Home: 4GB • Windows XP Professional: 4GB • OS X: 8GB due to current hardware limitations • OS 9.x: 1.5GB (no single application can utilize more than 1GB) • Linux: 64GB Rick Graziani [email protected] 59 3. The Speed of the CPU Speed measured in • megahertz (MHz) - the number of millions of beats per second • gigahertz (GHz) - the number of billions of beats per second Examples: • Early CPUs: 4 - 33 MHz • Current Processors: 3 GHz and more Faster the CPU, faster the processing (Toll Booth) Cost $$$ and Manufacturing Rick Graziani [email protected] 60 3. The Speed of the CPU Rick Graziani [email protected] 61 4. Internal Cache Internal Cache = memory inside the CPU chip which stores instructions and data which the CPU is currently working on or may soon need. • The CPU must deliver its data at a very high speed. • The regular RAM cannot keep up with that speed. • Therefore, a special RAM type called cache is used as a buffer temporary storage. • L1 Cache – Same chip as CPU (fastest) • L2 Cache – Separate chip Rick Graziani [email protected] 62 Apple G5 • • G5 drives the largest performance gain in the history of the PowerPC. The 64-bit G5 offers speeds up to 2.5GHz and can address up to 8GB of main memory. Rick Graziani [email protected] 63 Intel Duo Processor • • • • Two CPUs in one. Which means it can run at a slower clock speed without sacrificing performance. – Two oxen better than one. Less power consumed, runs cooler. 4 MB shared L2 cache. Rick Graziani [email protected] 64 Storage Devices Permanent Storage INPUT PROCESSOR OUTPUT PERMANENT STORAGE • What is in charge of permanent storage • devices? The operating system software! Rick Graziani [email protected] 66 Cost v.s. Speed Rick Graziani [email protected] 67 Direct Access Devices vs. Sequential Access Analogy: • Record/CD vs. Cassette Tape Rick Graziani [email protected] 68 Sequential Access Devices Sequential Access = In order to access specific information, the device must sequentially pass through all preceding information • 9 Track Tape (Reel to Reel) • Cartridge Tapes Rick Graziani [email protected] 69 Reel to Reel Tape (9 Track Tape) Rick Graziani [email protected] 70 Using a Cartridge Tape Drive Rick Graziani [email protected] 71 Storing Data on Tape Rick Graziani [email protected] 72 Storing Data on Tape Recording information • Bits are recorded as positive and negative polarity on magnetic tape (“magnetic media”) Advantages • inexpensive • durable • portable Disadvantages • slow access rate Primary Use Backing up “on-line” information Rick Graziani [email protected] 73 Direct Access Devices Direct Access = The specific information is accessed directly Examples • floppy disk drives • hard disk drives • cartridge disk drives • CD ROM and DVD drives Rick Graziani [email protected] 74 Floppy Disks Floppy Disk = iron oxide coating on a portable mylar plastic disk Becoming obsolete Old 5 1/4 inch diskettes (FYI) • double density = 360K capacity • high density = 1.2 MB capacity Rick Graziani [email protected] 75 Floppy Disks Newer 3 1/2 inch diskettes • double density = 720K capacity • high density = 1.4 MB capacity (Right drive for the right densities) Advantages of 3 1/2 inch • size, capacity, speed, durability Notch with slide = write protection • closed = Read/Write • open = Read Only Rick Graziani [email protected] 76 Recording information • Bits are recorded as positive and negative polarity on magnetic tape (“magnetic media”) Rick Graziani [email protected] 77 Magnetic Media is sensitive to: • temperature • magnets • touch, smoke, dirt • folding, bending, pressure Rick Graziani [email protected] 78 Hard Disk Drives Hard Disk = Iron oxide coating on one or more rigid aluminum disks called platters Rick Graziani [email protected] 79 Hard Disk Drives Common Sizes Older Disks • 5 MB, 10 MB, 20 MB, etc. Newer Disks • 50 GB and more! • Smaller, cheaper and faster! Advantages of Hard Disk Drives over Floppy Disk Drives • more capacity • faster access Rick Graziani [email protected] 80 How data is stored on disks Hotel analogy • • What is in charge of storing information on the hard disk drive (and other storage devices)? The operating system software! Rick Graziani [email protected] 81 How data is stored on disks track = a series of concentric rings on the disk • A track is divided into several sectors (track) sector =a section of a track which stores a predetermined number of bytes (bits) Rick Graziani [email protected] 82 How data is stored on disks Several sectors are combined to create clusters or blocks cluster (Windows and Macs) or block (UNIX) = The number of sectors which is allocated on the disk each time a file needs space on the disk. Windows 95 (later versions) and Windows 98 using FAT32 1 cluster = 8 sectors (4K bytes) Recognizes disk drives up to 2 terabytes (2 trillion bytes) Rick Graziani [email protected] 83 How data is stored on disks FAT (File Allocation Table) and Directory = A file, a table, which is found on one of the first sectors of every diskette and hard disk drive (created when the disk is formatted), and contains information regarding every file stored on that disk including the file name, the date and time that file was created or modified, the size of the file, and which sectors are allocated for that file. Example Creating a new file and saving an existing file to disk Rick Graziani [email protected] 84 Fragmentation and Defragmenting Rick Graziani [email protected] 85 How data is physically stored on the disk Read/Write Heads = Part of disk drive which skims the disk (ten millionths of an inch) in order to retrieve or store information. Disk Crash or Head Crash = When the R/W head touches the disk. Rick Graziani [email protected] 86 Formatting a disk Q: Why do we format a disk and what actually does it? A: We format a disk so it can be used by the operating system software. The operating system software does the formatting of the disk. Q: How does the operating system do it? A: There is a operating system software file (program) which does the formatting. (CPU/RAM) Rick Graziani [email protected] 87 Formatting a disk What does formatting a disk do? 1. Erases all of the information on the disk 2. Prepares disk to be used by the operating system software. • divides tracks into sectors • determines cluster size • creates a file allocation table (FAT) or similar table on other operating systems 3. Optional: Copies operating system files to this disk in order to make this a “boot disk” Rick Graziani [email protected] 88 How Data is Removed from Floppy disks and Hard disks Who's in charge of deleting files? Deleting a file: Unerasing a file Rick Graziani [email protected] 89 Recovering Data • Norton Utilities™ – Optimizes and defragments files for faster hard drive performance. – Detects and fixes many Windows® and disk problems automatically. – Can monitor your PC continuously to spot problems before they occur. Rick Graziani [email protected] 90 Optical Disks - CD ROMs Recording bits of data • Data is permanently recorded by a laser beam on a disk • WORM = Write Once Read Many Rick Graziani [email protected] 91 Pit = On No Pit (Land) = Off Rick Graziani [email protected] 92 Optical Disks - CD ROMs Advantages of CD ROM over magnetic disks • capacity and durability Disadvantage • WORM Read Only Drives and Read/Write CD ROM Drives Capacity • currently = 650 MB Rick Graziani [email protected] 93 Optical Disks - CD ROMs What are CD ROMs good for? • graphics, videos, games, software, (backups) Speed of CD ROM Drives • 4x, 6x, 8x, 10x, etc. • larger the number, faster the transfer speed from the CD ROM to RAM What’s next? • Need more capacity and faster speeds. Rick Graziani [email protected] 94 http://www.computerhope.com/help/cdrom.htm • OTHER CD TECHNOLOGIES • CD-R - (CD Recordable) Drive which you are able to write to once. Once the drive is written to it cannot be erased. CD-RW - (CD ReWritable) drive which is a popular alternative to the CD-R drive. CD-RW has the capability of being written to at least one thousand times. The drawback with CD-RW diskettes is with the lower reflectivity of the disc itself can limit the readability. Many CD-ROM and CD-R drives may have a difficult time reading these disks. DVD - (Digital Versatile Disc) New standard released in 1995 which originally was called Digital Video Disc was later changed to Digital Versatile Disc. DVD offers an initial storage capacity of 4.7GB (of digital information on a single-sided, single-layer disc the same diameter and thickness of a current CD-ROM. DVD-RAM - ReWritable drive type that uses a phase-change technology like the CD-RW drives. However , DVD-RAM discs cannot be read by standard DVD-ROM drives because of the differences in both reflectivity of the medium and the data format. Rick Graziani [email protected] 95 http://www.videohelp.com/dvd • DVD-R and DVD-RW – DVD-R was the first DVD recording format released that was compatible with standalone DVD Players. – DVD-R is a non-rewriteable format and it is compatible with about 93% of all DVD Players and most DVD-ROMs. – DVD-RW is a rewriteable format and it is compatible with about 80% of all DVD Players and most DVD-ROMs. – DVD-R and DVD-RW supports single side 4.37 computer GB* DVDs(called DVD-5) and double sided 8.75 computer GB* DVDs(called DVD-10). – These formats are supported by DVDForum. • DVD+R and DVD+RW – DVD+R is a non-rewritable format and it is compatible with about 89% of all DVD Players and most DVD-ROMs. – DVD+RW is a rewritable format and is compatible with about 79% of all DVD Players and most DVD-ROMs. – DVD+R and DVD+RW supports single side 4.37 computer GB* DVDs(called DVD-5) and double side 8.75 computer GB* DVDs(called DVD-10). – These formats are supported by the DVD+RW Alliance. Rick Graziani [email protected] 96 http://www.videohelp.com/dvd • DVD+R DL – DVD+R DL or called DVD+R9 is a Dual Layer writeable DVD+R. The dual layered discs can hold 7.95 computer GB* (called DVD-9) and dual layered double sides 15.9* computer GB (called dvd-18). • DVD-R DL – DVD-R DL or called DVD-R9 is a Dual Layer writeable DVD-R. The dual layered discs can hold 7.95 computer GB* (called DVD-9) and dual layered double sides 15.9* computer GB (called dvd-18). • • DVD-RAM DVD-RAM has the best recording features but it is not compatible with most DVD-ROM drives and DVD-Video players. Think more of it as a removable hard disk. DVD-RAM is usually used in some DVD Recorders. This format is supported by DVDForum. • Rick Graziani [email protected] 97 What are the features of DVD-Video? • • • • • • • • • • • • Over 2 hours of high-quality digital video (over 8 on a double-sided, duallayer disc). Support for widescreen movies and standard or widescreen TVs (4:3 and 16:9 aspect ratios). Up to 8 tracks of digital audio (for multiple languages), each with up to 8 channels. Up to 32 subtitle/karaoke tracks. Multilingual identifying text for title name, album name, song name, actors, etc. Automatic "seamless" branching of video (for multiple story lines or ratings on one disc). Up to 9 camera angles (different viewpoints can be selected during playback). Menus and simple interactive features (for games, quizzes, etc.). "Instant" rewind and fast forward, including search to title, chapter, track, and timecode. Durability (no wear from playing, only from physical damage). Not susceptible to magnetic fields. Resistant to heat. Compact size (easy to handle and store, players can be portable). Rick Graziani [email protected] 98 Disk Cartridges Disk Cartridges = portable disks which store almost as much information and is almost as fast as a hard disk drive Uses • same as floppy or tape Examples: Iomega Zip Drive = 100 MB Iomega Jaz Drive = 1 GB Rick Graziani [email protected] 99 Flash Drives • • Capacity – 64 MB – 128 MB – 256 MB – 512 MB – 1 GB – And more $35 to $175 Rick Graziani [email protected] 100 Overview of Computer Hardware CS 1 Introduction to Computers and Computer Technology Rick Graziani Fall 2006