© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Chapter 06: The System Unit

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-2 Introduction Speed, capacity, and flexibility determine the power of microcomputers.Speed, capacity, and flexibility determine the power of microcomputers. Knowledge of a computer’s power allows you to make good buying decisions and to determine if your current system will run new applications.Knowledge of a computer’s power allows you to make good buying decisions and to determine if your current system will run new applications. Competent end users need to understand the basic principles of how microcomputers are put together.Competent end users need to understand the basic principles of how microcomputers are put together.

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-3 System Unit Types Desktop System UnitsDesktop System Units Media Center System UnitsMedia Center System Units Notebook System UnitsNotebook System Units Tablet PC System UnitsTablet PC System Units Handheld ComputerHandheld Computer System UnitsSystem Units

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-4 System Unit System Chassis, System Board (Motherboard), Microprocessor, Memory, Socket, Bus Lines, and Expansion Slots

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-5 Electronic Data and Instructions Data and instructions are represented electronicallyData and instructions are represented electronically Two-state system or Binary SystemTwo-state system or Binary System –Off/On electrical states –Characters represented by 0’s (off) and 1’s (on) –Bits –Bytes

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-6 Character Coding Schemes Three types of binary coding schemesThree types of binary coding schemes –ASCII - American Standard Code for Information Exchange –EBCDIC - Extended Binary Coded Decimal Interchange Code –Unicode - handles languages with large numbers of characters

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-7 System Board Connects all componentsConnects all components Allows communication between devicesAllows communication between devices Main board or motherboardMain board or motherboard Circuit board componentsCircuit board components –Sockets –Slots –Bus lines

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-8 Microprocessor Chips Central Processing Unit (CPU)Central Processing Unit (CPU) –Measurement units for processing speed (shown here) Two Basic ComponentsTwo Basic Components –Control unit –Arithmetic-logic unit (ALU)

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-9 Microprocessor Chips Chip capacities are expressed in word sizesChip capacities are expressed in word sizes Two significant developmentsTwo significant developments –64-bit processors Have become standard for most of today’s desktop and laptop computersHave become standard for most of today’s desktop and laptop computers –Multi-Core Chips Can provide two separate and independent CPUsCan provide two separate and independent CPUs Parallel ProcessingParallel Processing

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-10 Memory Holding area for data, instructions, and informationHolding area for data, instructions, and information Memory is contained on chips connected to the system boardMemory is contained on chips connected to the system board Types of memory chipsTypes of memory chips –RAM – Programs and data RAM –ROM – Fixed start-up instructions ROM –Flash – Flexible start-up instructions Flash

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-11 RAM Random Access Memory (RAM) chips hold the program and dataRandom Access Memory (RAM) chips hold the program and data –Cache memory or RAM cache –Flash RAM or flash memory Other types of RAMOther types of RAM –DRAM –SDRAM –DDR –Direct RDRAM Return

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-12 ROM Read-only memory (ROM) chips are not volatile and cannot be changed by the userRead-only memory (ROM) chips are not volatile and cannot be changed by the user CPU can read, or retrieve data and programs but the computer cannot writeCPU can read, or retrieve data and programs but the computer cannot write Contain special instructionsContain special instructions –Needed to start a computer –Give keyboard keys their special capabilities –Put characters on screen Return

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-13 Flash Flash memory offers a combination of the features of RAM and ROM.Flash memory offers a combination of the features of RAM and ROM. Flash memory is used for a wide of range of applications.Flash memory is used for a wide of range of applications. If changes are made to the computer system, these changes are reflected in flash memory.If changes are made to the computer system, these changes are reflected in flash memory. Return

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-14 Expansion Slots and Cards Allows for new devices to be addedAllows for new devices to be added –Open architecture –Slots provide for expansion Expansion cards are also calledExpansion cards are also called –Plug-in boards –Controller cards –Adapter cards –Interface cards

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-15 Commonly Used Expansion Cards Graphics cardsGraphics cards Sound cardsSound cards Network interface cards (NIC)Network interface cards (NIC) Wireless network cardsWireless network cards PC cards & Express cardsPC cards & Express cards TV tuner cardsTV tuner cards

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-16 TV Tuner Cards And Video Clips Allows you to view your favorite TV shows while running other applications such as ExcelAllows you to view your favorite TV shows while running other applications such as Excel Video can be captured to a file, added to a Web page, attached to an , or added to a class presentationVideo can be captured to a file, added to a Web page, attached to an , or added to a class presentation Inexpensive and easy to installInexpensive and easy to install

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-17 Plug and Play Set of specific hardware and software standards developed by Intel, Microsoft, and othersSet of specific hardware and software standards developed by Intel, Microsoft, and others Creating devices that are able to configure themselves when installedCreating devices that are able to configure themselves when installed

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-18 Bus Lines Connect parts of the CPU to each otherConnect parts of the CPU to each other Data roadway for traveling bitsData roadway for traveling bits –Measured as bus width –More lanes, faster traffic Two basic categoriesTwo basic categories –System buses –Expansion buses

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-19 Expansion Buses Connects the CPU to other components on the system board, including expansion slotsConnects the CPU to other components on the system board, including expansion slots Principal typesPrincipal types –Peripheral Component Interconnect (PCI) –Universal serial bus (USB) –FireWire buses –Serial Advanced Technology Attachment (SATA) –PCI Express (PCIe)

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-20 Ports Socket for connecting external devicesSocket for connecting external devices Ports can connect directly to the system board or they can connect to cards that are inserted into slots on the system boardPorts can connect directly to the system board or they can connect to cards that are inserted into slots on the system board Three TypesThree Types –Standard Ports Standard PortsStandard Ports –Legacy Ports Legacy PortsLegacy Ports –Specialized Ports Specialized PortsSpecialized Ports

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-21 Standard Ports Four common portsFour common ports –VGA –USB ports –FireWire ports –Ethernet ports Return

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-22 Legacy Ports Serial portsSerial ports Parallel portsParallel ports Keyboard and mouse portsKeyboard and mouse ports Infrared data association (IrDA)Infrared data association (IrDA) Game portsGame ports Return

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-23 Specialized Ports Three specialized portsThree specialized ports –Musical Instrument digital interface (MIDI) –Sony/Philips Digital Interconnect Format (S/PDIF) –High Definition Multimedia Interface (HDMI) Return

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-24 Cables Used to connect external devices to the system unit via the portsUsed to connect external devices to the system unit via the ports One end of the cable is attached to the device and the other end has a connector that is attached to a matching connector on the portOne end of the cable is attached to the device and the other end has a connector that is attached to a matching connector on the port

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 6-25 Power Supply Computers require direct current (DC)Computers require direct current (DC) DC power provided by converting alternating current (AC) from wall outlets or batteriesDC power provided by converting alternating current (AC) from wall outlets or batteries Desktop computers use power supply unitsDesktop computers use power supply units Notebooks and handhelds use AC adaptersNotebooks and handhelds use AC adapters