11COMPUTERHARDWARETECHNOLOGIES© Abdou Illia, Spring 2007(Week 2, Thursday 1/18/2007)2LEARNING GOALS Identify the major components of modern PCs Explain how the components of a computer work together; Explain input devices and how they operate. Describe output devices and how they operate. Describe I/O (secondary storage) devices and how they operate. Explain the role of the CPU and the RAM. Describe various types of computers.3The Core Computer Components Three subsystems in a computer system:1. Input subsystem2. Processing subsystem3. Output subsystem24Input subsystem Main functions:  Allowing the user to enter data Transmitting data to the Processing subsystem Includes keyboard, mouse, and other input devices Question: Name five other input devices ____________________________ ____________________________ ____________________________ ____________________________ ____________________________5Input Devices Human input devices Allow a person to send data to the computer Examples: Keyboard, Mouse Machine-readable input devices Send data directly to computer without human involvement No human involvement means no human error Usually faster than human input Examples: Bar codes reader, Optical Characters Recognition (OCR) system6Machine-readable Input Devices Bar code scanners Uses light to read series of coded stripes Universal Product Code (UPC) – Adams.com Optical Character Recognition (OCR) Includes OCR Software and scanner Translates scanned digital image to character that user can recognize and manipulate Magnetic Ink Character Recognition (MICR) Character recognition technology used by banks to allow rapid routing of checks between banks37Output subsystem Main function: Show processing results Includes monitor, printer, and other output devices Q: Name two other output devices ____________________________ ____________________________8Output Devices Monitors Cathode ray tube (CRTs) Liquid crystal displays (LCDs) Quality of display Resolution in pixels (e.g. 640 x 480) Dot pitch in millimeters (.26 to .28) Active-Matrix vs. Passive-Matrix displayTouch screens Input and output via display device1024 x 768 or 1280 x 102419 inches800 x 600 or 1024 x 76817 inches640 x 48015 inchesCommon resolutionMonitor size9410Printers Speed and resolution Pages per minute (PPM) Dots per inch (DPI) Number of ink dots to fill a square inch Higher DPI = greater page clarityImpact printers Create image by striking paper and ribbon Dot-matrix printers = most common impact printers Non-impact printers Create image by spraying or rolling ink on the page11Non-impact Printers Ink-jet technology printers Spray ink on the paper Quiet Color is readily and cheaply available Laser printers Laser heats drum which rolls ink (toner) on paper Can be faster than ink-jet More expensive than ink-jet12I/O devices or Secondary Storage Nonvolatile storage of digital data Magnetic or opticalMagnetic storage (Floppy disk, Magnetic tape, Zip disk, Hard disk) Sequential access (tape) or direct access (HDD) Hard disk drives Two main standards: IDE (Integrated Drive Electronics) aka ATA (AT Attachment) SCSI (Small Computer System Interface) SCSI allows disk fault-tolerance through RAID – Redundant Array of Inexpensive Disks Disk speed: Transfer rate in MBps (Megabytes per second) Average Read Time (in milliseconds or ms) Platter rotation speed in RPM (5400/7200/10,000/15,000)513Optical Secondary Storage Compact disks (CDs) 600 MB capacity CD-ROM CD-R CD-RW Digital versatile disks (DVDs) 2 – 17 GB capacity DVD DVD+/-R DVD+/-RW1415Processing subsystem Two major components CPU (Central Processing Unit) or Processor(s) Primary Storage: Random Access Memory (RAM) Read Only Memory (ROM)CPUPrimary StorageBusses that transfer data616Central Processing Unit Clock: generate time that synchronize other components ICU: Fetches instructions from RAM ALU: Execute instructions (arithmetic & logic operations) Registers: Store control information, data, intermediate resultsProcessorClockInstruction Control UnitArithmetic Logic UnitRegisters17CPU speed Speed measured in hertz Hertz = # of instructions executed per second Megahertz = 1 million of instructions per second Gigahertz = 1 billion of instructions per second- Athlon series (which compete with Intel Pentium 4)IBM- PowerPC 740, 750, 750FX, 750GL, 750GX- K6 series processors (which compete with Intel Pentium 3)Advanced Micro Devices (AMD)- Pentium 3, Pentium 4, Pentium 4 Xeon, Dual Core- CeleronIntelMajor Processor manufacturers18Primary Storage RAM holds running programs and the data they use ROM contains critical programs such as those that boot the computerPrimary StorageRAMROM Computer’s memory stored on semiconductor chips Two categories: RAM (Random Access Memory) which is volatile Synchronous Dynamic RAM (SDRAM) Double Data Rate SDRAM or DDR SDRAM ROM (Read-Only Memory) which is non-volatile Capacity in Megabytes (MB) or Gigabytes (GB)Program Data719Moore’s Law on Processor Speed RAM capacity tends to double every 18-24 months Processor speed tends to double every 18-24 months20Types of Computers Supercomputers Mainframes Minicomputers Servers Workstations Desktop computers Notebook computers (laptops) Handheld computers (PDAs)21Bead Bar : Exercise 2Visit Dell website at www.dell.com in order to choose a computer system for Bead Bar. You must select the components based on the assessment of needs prepared by Stan after interviewing the Bead Bar employees (See the Assignment section’s of the course website for a copy of Stan’s memo to you) . Your job consist in filling out the Computer Hardware specification form found in the Assignment section of the course website with the characteristics of the computer system you have selected. Your assignment must include the printout of the description of the computer system from Dell website.822Summary Questions6) (a) Name main components of the Processing subsystem. (b) What is the function of the ALU?8) Describe the various types of computers.7) Explain the difference between RAM and ROM.5) Name the two main types of monitors used in today’s computer systems.3)