CHAPTER 2 Computer Hardware

Chapter Contents Section A: Data Representation and Digital Electronics Section B: Microprocessors and Memory Section C: Storage Devices Section D: Input and Output Devices Chapter 2: Computer Hardware

Section A: Data Representation and Digital Electronics Quantifying Bits and Bytes Digital Electronics Chapter 2: Computer Hardware

Data Representation Process of transforming diverse data into a form computers can use for processing Digital devices work with distinct and separate data Analog devices work with continuous data Chapter 2: Computer Hardware

Data Representation Numeric data Character data Binary number system Character data ASCII, Extended ASCII, and Unicode Digitizing is the process of converting analog data into digital format File headers contain information about the code used to represent file data Chapter 2: Computer Hardware

Data Representation Chapter 2: Computer Hardware

Quantifying Bits and Bytes Chapter 2: Computer Hardware

Digital Electronics Bits take the form of electrical pulses that can travel over circuits System unit Chapter 2: Computer Hardware

Digital Electronics An integrated circuit (computer chip) is a super-thin slice of semiconducting material packed with microscopic circuit elements Chapter 2: Computer Hardware

Digital Electronics The computer’s main circuit board is called the system board, or motherboard Chapter 2: Computer Hardware

Section B: Microprocessors and Memory Microprocessor Basics Microprocessor Performance Factors Today’s Microprocessors Random Access Memory Read-only Memory CMOS Memory Buying a Computer Chapter 2: Computer Hardware

Microprocessor Basics A microprocessor is an integrated circuit designed to process instructions ALU Registers Control unit Instruction set Chapter 2: Computer Hardware

Microprocessor Performance Factors Microprocessor clock Megahertz Gigahertz Word size Cache Level 1 cache (L1) Level 2 cache (L2) CISC vs. RISC technology Chapter 2: Computer Hardware

Microprocessor Performance Factors Serial processing Pipelining Parallel processing Chapter 2: Computer Hardware

Microprocessor Performance Factors Dual core processors contain the circuitry for two microprocessors Benchmark tests gauge the overall speed of a microprocessor Chapter 2: Computer Hardware

Today’s Microprocessors Chapter 2: Computer Hardware

Random Access Memory Random Access Memory is a temporary holding area for data, application program instructions, and the operating system Chapter 2: Computer Hardware

Random Access Memory Microscopic capacitors hold the bits that represent data Most RAM is volatile Requires electrical power to hold data Chapter 2: Computer Hardware

Random Access Memory RAM capacity is expressed in megabytes or gigabytes Personal computers typically feature between 128 MB and 2 GB of RAM An area of the hard disk, called virtual memory, can be used if an application runs out of allocated RAM Chapter 2: Computer Hardware

Random Access Memory RAM speed is often expressed in nanoseconds or megahertz SDRAM is fast and relatively inexpensive DDR RDRAM is more expensive, and usually found in high-performance workstations Chapter 2: Computer Hardware

Read-Only Memory ROM is a type of memory circuitry that holds the computer’s startup routine Permanent and non-volatile The ROM BIOS tells the computer how to access to hard disk, find the operating system, and load it into RAM Chapter 2: Computer Hardware

CMOS Memory Stores basic system information More permanent than RAM, and less permanent than ROM Requires very little power to hold data Chapter 2: Computer Hardware

Buying a Computer Assess your budge Think about how you plan to use your computer Look at ads and visit online computer stores Chapter 2: Computer Hardware

Section C: Storage Devices Storage Basics Floppy Disk Technology Hard Disk Technology Tape Storage CD and DVD Technology Solid State Storage Chapter 2: Computer Hardware

Storage Basics A storage medium contains data A storage device records and retrieves data from a storage medium Data gets copied from a storage device into RAM, where it waits to be processed Processed data is held temporarily in RAM before it is copied to a storage medium Chapter 2: Computer Hardware

Storage Basics Magnetic storage stores data by magnetizing microscopic particles on the disk or tape surface Chapter 2: Computer Hardware

Storage Basics Optical storage stores data as microscopic light and dark spots on the disk surface CD and DVD storage technologies Chapter 2: Computer Hardware

Storage Basics Solid state storage technology stores data in a non-volatile, erasable, low-power chip Some solid state storage requires a card reader to transfer data to or from a computer Chapter 2: Computer Hardware

Storage Basics Most desktop computers have several drive bays, some accessible from outside the case, and others—designed for hard disk drives—without any external access. Empty drive bays are typically hidden from view with a face plate. CLICK TO START Chapter 2: Computer Hardware

Storage Basics Versatility Durability Speed Capacity Access time Random vs. sequential access Data transfer rate Capacity Chapter 2: Computer Hardware

Floppy Disk Technology Used for standard HD DS disks and Zip disks Chapter 2: Computer Hardware

Hard Disk Technology Hard disk platters are sealed inside the drive case or cartridge to prevent dust and other contaminants from interfering with the read-write heads. CLICK TO START Chapter 2: Computer Hardware

Hard Disk Technology A controller positions the disk and read-write heads to locate data SATA Ultra ATA EIDE SCSI Not as durable as many other storage technologies Head crash Chapter 2: Computer Hardware

Tape Storage A tape backup stores a copy of the data on a hard disk on a magnetic tape A tape is a sequential storage medium Chapter 2: Computer Hardware

CD and DVD Technology A CD can hold up to 80 minutes of music or 700 MB of data A DVD can hold about 4.7 GB of data A double-layer DVD can store 8.5 GB of data HD-DVDs can store 15 GB Blu-ray DVDs can store 25 GB Chapter 2: Computer Hardware

CD and DVD Technology CD-DA DVD-Video CD-ROM DVD-ROM CD-R DVD+R or DVD-R CD-RW DVD+RW or DVD-RW Chapter 2: Computer Hardware

CD and DVD Technology Chapter 2: Computer Hardware

Solid State Storage USB flash drive CompactFlash (CF) cards MultiMedia cards (MMC) SecureDigital (SD) SmartMedia Chapter 2: Computer Hardware

Section D: Input and Output Devices Basic Input Devices Display Devices Printers Installing Peripheral Devices Chapter 2: Computer Hardware

Basic Input Devices Keyboard Pointing device Pointing stick Trackpad Trackball Joystick Chapter 2: Computer Hardware

Display Devices A CRT display device uses a bulky glass tube An LCD manipulates light within a layer of liquid crystal cells Plasma screen technology illuminates lights arranged in a panel-like screen Chapter 2: Computer Hardware

Display Devices Viewable image size Dot pitch Viewing angle width Refresh rate Color depth Resolution VGA, SVGA, XGA, SXGA, and UXGA Chapter 2: Computer Hardware

Display Devices Chapter 2: Computer Hardware

Display Devices Graphics circuitry generates the signals for displaying an image on the screen Integrated graphics Graphics card Chapter 2: Computer Hardware

Printers An ink-jet printer has a nozzle-like print head that sprays ink onto paper A laser printer works like a photocopier Chapter 2: Computer Hardware

Printers Laser printers are a popular technology when high-volume output or good-quality printouts are required. CLICK TO START Chapter 2: Computer Hardware

Printers Dot matrix printers produce characters and graphics by using a grid of fine wires The wires strike a ribbon and the paper Chapter 2: Computer Hardware

Printers Other printer technologies include solid ink printers, thermal transfer printers, and dye sublimation printers Printer features Resolution Print speed Duty cycle Operating costs Duplex capability Memory Chapter 2: Computer Hardware

Installing Peripheral Devices The data bus moves data within the computer Expansion cards are small circuit boards that give the computer additional capabilities Expansion slot ISA PCI AGP PCMCIA Chapter 2: Computer Hardware

Installing Peripheral Devices An expansion card simply slides into an expansion slot and is secured with a small screw. Before you open the case, make sure you unplug the computer and ground yourself—that’s technical jargon for releasing static electricity by using a special grounding wristband or by touching both hands to a metal object. CLICK TO START Chapter 2: Computer Hardware

Installing Peripheral Devices An expansion port passes data in and out of a computer or peripheral device Peripheral device may include the Plug and Play feature, or require a device driver Chapter 2: Computer Hardware

Installing Peripheral Devices Chapter 2: Computer Hardware

CHAPTER 2 COMPLETE Computer Hardware