Computer System Unit Components & Storage - PDF

Chapter Two System Unit Components & Types of Storage Discovering Computers Your Interactive Guide to the Digital World The System Unit The system unit is a case that contains electronic components of the computer used to process data Page 210...

Chapter Two System Unit Components & Types of Storage Discovering Computers Your Interactive Guide to the Digital World The System Unit The system unit is a case that contains electronic components of the computer used to process data Page 210 Discovering Computers : Chapter 4 2 Figure 4-1 The System Unit The inside of the system unit on a desktop personal computer includes: Drive bay(s) Power supply Sound card Video card Processor Memory Page 211 Discovering Computers : Chapter 4 3 Figure 4-2 The System Unit The motherboard is the main circuit board of the system unit – A computer chip contains integrated circuits Page 212 Discovering Computers : Chapter 4 4 Figure 4-3 Processor The processor, also called the central processing unit (CPU), interprets and carries out the basic instructions that operate a computer – Contain a control unit and an arithmetic logic unit (ALU) Multi-core Dual-core Quad-core processor processor processor Page 213 Discovering Computers : Chapter 4 5 Processor Page 213 Discovering Computers : Chapter 4 6 Figure 4-4 Processor The control unit is the component of the processor that directs and coordinates most of the operations in the computer The arithmetic logic unit (ALU) performs arithmetic, comparison, and other operations Page 214 Discovering Computers : Chapter 4 7 Processor For every instruction, a processor repeats a set of four basic operations, which comprise a machine cycle Page 215 Discovering Computers : Chapter 4 8 Figure 4-5 Processor Most current personal computers support pipelining – Processor begins fetching a second instruction before it completes the machine cycle for the first instruction Pages 215 – 216 Discovering Computers : Chapter 4 9 Figure 4-6 Processor The processor contains registers, that temporarily hold data and instructions The system clock controls the timing of all computer operations The pace of the system clock is called the clock speed, and is measured in gigahertz (GHz) Page 216 Discovering Computers : Chapter 4 10 Processor The leading manufacturers of personal computer processor chips are Intel and AMD Pages 216 – 217 Discovering Computers : Chapter 4 11 Figure 4-7 Processor A processor chip generates heat that could cause the chip to burn up Require additional cooling – Heat sinks – Liquid cooling technology Pages 219 - 220 Discovering Computers : Chapter 4 12 Figures 4-9 – 4-10 Processor Parallel processing uses multiple processors simultaneously to execute a single program or task – Massively parallel processing involves hundreds or thousands of processors Page 220 Discovering Computers : Chapter 4 13 Figure 4-11 Data Representation Analog signals are continuous and vary in strength and quality Digital signals are in one of two states: on or off Most computers are digital The binary system uses two unique digits (0 and 1) Bits and bytes Page 221 Discovering Computers : Chapter 4 14 Data Representation A computer circuit represents Eight bits grouped together as a the 0 or the 1 electronically by unit are called a byte. A byte the presence or absence of an represents a single character in electrical charge the computer Page 221 Discovering Computers : Chapter 4 15 Figures 4-12 – 4-13 Data Representation ASCII (American Standard Code for Information Interchange) is the most widely used coding scheme to represent data Page 221 Discovering Computers : Chapter 4 16 Figure 4-14 Data Representation Page 222 Discovering Computers : Chapter 4 17 Figure 4-15 Memory Memory consists of electronic components that store instructions waiting to be executed by the processor, data needed by those instructions, and the results of processing the data Stores three basic categories of items: Data being The operating Application processed and the system and other programs resulting system software information Page 223 Discovering Computers : Chapter 4 18 Memory Each location in memory has an address Memory size is measured in kilobytes (KB or K), megabytes (MB), gigabytes (GB), or terabytes (TB) Page 223 Discovering Computers : Chapter 4 19 Figure 4-17 Memory The system unit contains two types of memory: Volatile memory Nonvolatile memory Loses its contents when Does not lose contents power is turned off when power is removed Examples include ROM, Example includes RAM flash memory, and CMOS Pages 223 - 224 Discovering Computers : Chapter 4 20 Memory Memory cache speeds the processes of the computer because it stores frequently used instructions and data Page 227 Discovering Computers : Chapter 4 21 Figure 4-22 Memory Read-only memory (ROM) refers to memory chips storing permanent data and instructions Firmware A PROM (programmable read-only memory) chip is a blank ROM chip that can be written to permanently EEPROM can be erased Page 228 Discovering Computers : Chapter 4 22 Memory Flash memory can be erased electronically and rewritten – CMOS technology provides high speeds and consumes little power Pages 228 – 229 Discovering Computers : Chapter 4 23 Figure 4-23 Memory Access time is the amount of time it takes the processor to read from memory – Measured in nanoseconds Page 229 Discovering Computers : Chapter 4 24 Figures 4-24 – 4-25 Expansion Slots and Adapter Cards With Plug and Play, the computer automatically can configure adapter cards and other peripherals as you install them Pages 230 – 231 Discovering Computers : Chapter 4 25 Figure 4-27 Expansion Slots and Adapter Cards Removable flash memory includes: – Memory cards, USB flash drives, and PC Cards/ExpressCard modules Page 231 Discovering Computers : Chapter 4 26 Figure 4-28 Ports and Connectors Page 233 Discovering Computers : Chapter 4 27 Figure 4-31 Ports and Connectors A USB port can connect up to 127 different peripherals together with a single connector – You can attach multiple peripherals using a single USB port with a USB hub Page 234 Discovering Computers : Chapter 4 28 Figure 4-32 Ports and Connectors A Bluetooth wireless port A smart phone might adapter converts a USB port into communicate with a notebook a Bluetooth port computer using an IrDA port Page 235 Discovering Computers : Chapter 4 29 Figures 4-33 – 4-34 Power Supply The power supply converts the wall outlet AC power into DC power Some external peripherals have an AC adapter, which is an external power supply Page 239 Discovering Computers : Chapter 4 30 Keeping Your Computer or Mobile Device Clean Clean your computer or mobile device once or twice a year Turn off and unplug your computer or mobile device before cleaning it Use compressed air to blow away dust Use an antistatic wipe to clean the exterior of the case and a cleaning solution and soft cloth to clean the screen Page 240 Discovering Computers : Chapter 4 31 Storage Storage holds data, instructions, and information for future use A storage medium is the physical material on which a computer keeps data, instructions, and information Pages 352 - 353 Discovering Computers : Chapter 7 32 Storage Pages 352 – 353 Discovering Computers : Chapter 7 33 Figure 7-1 Storage Capacity is the number of bytes a storage medium can hold Page 354 Discovering Computers : Chapter 7 34 Figure 7-2 Storage A storage device is the computer hardware that records and/or retrieves items to and from storage media Reading is the process of transferring items from a storage medium into memory Writing is the process of transferring items from memory to a storage medium Page 354 Discovering Computers : Chapter 7 35 Hard Disks A hard disk contains one or more inflexible, circular platters that use magnetic particles to store data, instructions, and information Page 355 Discovering Computers : Chapter 7 36 Figure 7-5 Hard Disks Hard disks can store data using longitudinal recording or perpendicular recording Page 356 Discovering Computers : Chapter 7 37 Figure 7-6 Hard Disks Page 358 Discovering Computers : Chapter 7 38 Figure 7-9 Hard Disks An external hard disk is a separate free- standing hard disk that connects to your computer with a cable or wirelessly A removable hard disk is a hard disk that you insert and remove from a drive Internal and external hard disks are available in miniature sizes (miniature hard disks) Pages 360 – 361 Discovering Computers : Chapter 7 39 Figures 7-14 – 7-15 Flash Memory Storage Pages 364 – 365 Discovering Computers : Chapter 7 40 Figures 7-18 – 7-19 Flash Memory Storage USB flash drives plug into a USB port on a computer or mobile device Page 367 Discovering Computers : Chapter 7 41 Figure 7-21 Cloud Storage Cloud storage is an Internet service that provides storage to computer users Page 368 Discovering Computers : Chapter 7 42 Figure 7-23 Cloud Storage Page 368 Discovering Computers : Chapter 7 43 Figure 7-24 Cloud Storage Users subscribe to cloud storage for a variety of reasons: Access files from any computer Store large files instantaneously Allow others to access their files View time-critical data and images immediately Store offsite backups Provide data center functions Page 369 Discovering Computers : Chapter 7 44 Optical Discs An optical disc consists of a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser Typically store software, data, digital photos, movies, and music Read only vs. rewritable Page 370 Discovering Computers : Chapter 7 45 Figure 7-25 Optical Discs Optical discs commonly store items in a single track that spirals from the center of the disc to the edge Track is divided into evenly sized sectors Page 371 Discovering Computers : Chapter 7 46 Figure 7-27 Optical Discs Care of optical discs Page 371 Discovering Computers : Chapter 7 47 Figure 7-28 Optical Discs A CD-ROM can be read from but not written to Read from a CD-ROM drive or CD-ROM player A CD-R is a multisession optical disc on which users can write, but not erase A CD-RW is an erasable multisession disc Must have a CD-RW drive Pages 372 – 373 Discovering Computers : Chapter 7 48 Figure 7-29 Optical Discs A DVD-ROM is a high-capacity optical disc on which users can read but not write or erase Requires a DVD-ROM drive A Blu-ray Disc-ROM (BD-ROM) has a storage capacity of 100 GB DVD-RW, DVD+RW, and DVD+RAM are high- capacity rewritable DVD formats Pages 375 – 376 Discovering Computers : Chapter 7 49 Figure 7-29 Other Types of Storage Page 376 Discovering Computers : Chapter 7 50 Other Types of Storage Tape is a magnetically coated ribbon of plastic capable of storing large amounts of data and information A tape drive reads and writes data and information on a tape Page 376 Discovering Computers : Chapter 7 51 Figure 7-35 Other Types of Storage A magnetic stripe card contains a magnetic stripe that stores information A smart card stores data on a thin microprocessor embedded in the card Page 377 Discovering Computers : Chapter 7 52 Figure 7-36 Other Types of Storage Microfilm and microfiche store microscopic images of documents on a roll or sheet film Page 378 Discovering Computers : Chapter 7 53 Figure 7-37 Other Types of Storage Page 378 Discovering Computers : Chapter 7 54 Figure 7-38 Other Types of Storage Enterprise storage stores huge volumes of data and information for large businesses – Uses special hardware for heavy use, maximum availability, and maximum efficiency Page 379 Discovering Computers : Chapter 7 55 Figure 7-39