Chapter 4 The Components of the System Unit
Chapter 4 Objectives Differentiate among various styles of system units Identify chips, adapter cards, and other components of a motherboard Describe the components of a processor and how they complete a machine cycle Identify characteristics of various personal computer processors on the market today Define a bit and describe how a series of bits represents data Explain how programs transfer in and out of memory Differentiate among the various types of memory Describe the types of expansion slots and adapter cards Explain the differences among a serial port, a parallel port, a USB port, a FireWire port, and other ports Describe how buses contribute to a computer’s processing speed Identify components in mobile computers and mobile devices Understand how to clean a system unit Next
The System Unit What is the   system unit ?   p. 184 Fig. 4-1 Case that contains electronic components of the computer used  to process data Sometimes called  the   chassis Next
The System Unit What are common components inside the system unit? p. 185 Fig. 4-2 Memory Adapter   cards Sound card Video card Drive bays Power   supply Processor Next
The System Unit What is the   motherboard ? p. 186 Fig. 4-3 Main circuit board of the system unit Contains expansion slots, processor chips, and memory slots Also called   system board Next Click to view Web Link, click Chapter 4, Click Web Link from left navigation,  then click Motherboards below Chapter
The System Unit What is a   chip ? p. 186 Small piece of semi-conducting material on which integrated circuits are etched Integrated circuits contain many microscopic pathways capable of carrying electrical current Chips are packaged so they can be attached to a circuit board Next
Processor What is the   central processing unit (CPU) ? Arithmetic  Logic Unit (ALU) p. 187 - 188 Fig. 4-4 Input Devices Storage Devices Output Devices Interprets and carries out basic instructions that operate a computer Memory Data Information Control  Unit Control unit  directs and coordinates operations in computer Arithmetic logic unit  (ALU)  performs  arithmetic, comparison,  and logical operations Also called the   processor Processor Control  Unit Arithmetic  Logic Unit (ALU) Next Instructions Data Information Instructions Data Information
Processor What is a   machine cycle? p. 188 Fig. 4-5 Step 1.  Fetch   Obtain program instruction or data item from memory Step 2.  Decode   Translate instruction into commands Step 4.  Store   Write result to memory Step 3.  Execute   Carry out command Four operations of the CPU comprise a machine cycle Processor Control Unit Memory ALU Next
Processor What is   pipelining? p. 189 Fig. 4-6 Processor begins fetching second instruction before completing machine cycle for first instruction Results in faster processing Next
Processor What is a   register? Stores location  from where instruction  was fetched Stores  instruction while it is  being decoded p. 189 Stores data  while ALU  computes it Stores results  of calculation Temporary high-speed storage area that holds  data and instructions Next
Processor What is the   system clock ? p. 189 - 190 Each tick  is a  clock cycle Pace of system  clock is  clock speed Most clock speeds are  in the gigahertz (GHz)  range (1 GHz = one  billion ticks of system  clock per second) Processor speed can  also be measured in  millions of instructions  per second (MIPS) Controls timing of all computer operations Generates regular electronic pulses, or ticks, that set operating pace of components of system unit Next
Processor What are  dual-core  and  multi-core processors ? p. 190 A  dual-core processor  is a single chip that contains two separate processors A  multi-core processor  is a chip with two or more separate processors Each processor on a dual-core/multi-core chip generally runs at a slower clock speed, but increase overall performance Next Click to view Web Link, click Chapter 4, Click Web Link from left navigation,  then click Multi-Core Processors  below Chapter 4
Processor What are the guidelines for selecting a processor? p. 192 Fig. 4-8 Next
Processor What are   heat sinks, heat pipes, and liquid cooling? p. 193 Fig. 4-9 Heat sink—component  with fins that cools  processor Heat pipe e —smaller  device for notebook  computers Liquid cooling—uses a continuous flow  of fluids to transfer heat away Next
Processor What is   parallel processing? p. 194 Fig. 4-10 Control Processor Results combined Using multiple processors simultaneously to execute a program faster Requires special software to divide problem and bring results together Next Processor 1 Memory Processor 2 Memory Processor 3 Memory Processor 4 Memory
Data Representation How do computers represent data? p. 194 - 195 Fig. 4-11 Recognize only two discrete states: on or off Use a  binary system  to recognize two states Use Number system with two unique digits: 0 and 1, called  bits  (short for binary digits) Most computers are   digital Next
Data Representation What is a   byte ? p. 195 Fig. 4-12 Eight bits grouped together as a unit Provides enough different combinations of 0s and 1s to represent 256 individual characters Numbers Uppercase  and lowercase  letters Punctuation  marks Other Next
Data Representation What are three popular coding systems to represent data? p. 195 Fig. 4-13 ASCII—American   Standard   Code   for   Information   Interchange EBCDIC—Extended   Binary   Coded Decimal   Interchange   Code Unicode—coding scheme capable of representing all world’s languages Next ASCII Symbol EBCDIC 00110000 0 11110000 00110001 1 11110001 00110010 2 11110010 00110011 3 11110011
Data Representation How is a letter converted to binary form and back? p. 196 Fig. 4-14 Step 3. The system unit converts the scan code for the capital letter  T  to its ASCII binary code (01010100) and stores it in memory for processing. Next Step 2. An electronic signal for the capital letter  T  is sent to the system unit. Step 4. After processing, the binary code for the capital letter  T  is converted to an image, and displayed on the output device. T Step 1. The user presses the capital letter  T  (SHIFT+T key) on the keyboard.
Memory What is   memory ? p. 197 Fig. 4-15 Electronic components that store instructions, data, and results Consists of one or  more chips on  motherboard or other circuit board Each byte stored  in unique location  called an   address,  similar to seats in a concert hall Next
Memory How is memory measured? p. 197 Fig. 4-16 By number of bytes available for storage Next Term Abbreviation Approximate Size Kilobyte KB or K 1 thousand bytes Megabyte MB 1 million bytes Gigabyte GB 1 billion bytes Terabyte TB 1 trillion bytes
Memory What is   random access memory ( RAM ) ? p. 198 - 199 The more RAM a  computer has, the  faster it responds Also called  main memory  or primary  storage Most RAM is  volatile, it is lost  when computer’s  power is  turned off Memory chips that can be  read from and written  to by processor Next Click to view Web Link, click Chapter 4, Click Web Link from left navigation,  then click RAM below Chapter
Memory How do program instructions transfer in and out of RAM? p. 198 Fig. 4-17 Step 1.   When you start the computer, certain operating system files are loaded into RAM from the hard disk. The operating system displays the user interface on the screen. Operating system instructions Web browser  instructions Paint program instructions Operating system interface Web browser  window Paint program window Web browser program instructions are removed from RAM Web browser window is no longer displayed on desktop Step 2.   When you start a Web browser, the program’s instructions are loaded into RAM from the hard disk. The Web browser window is displayed on the screen. Step 3.   When you start a paint program, the program’s instructions are loaded into RAM from the hard disk. The paint program, along with the Web Browser and certain operating system instructions are in RAM. The paint program window is displayed on the screen. Step 4.   When you quit a program, such as the Web browser, its program instructions are removed from RAM. The Web browser is no longer displayed on the screen. Next RAM RAM
Memory Video: The Leopard with a Time Machine Next CLICK TO START
Memory What are two basic types of RAM chips? p. 199 Static  RAM  (SRAM) Dynamic  RAM  (DRAM) Newer Type: Magnetoresistive RAM (MRAM) Must be  re-energized  constantly Do not have to be re-energized as often as DRAM Most  common  type Faster and  more reliable  than DRAM  chips Next
Memory Where does memory reside? p. 199 Fig. 4-18 Resides on small circuit board called   memory module Memory slots   on motherboard hold memory modules memory chip memory slot dual inline memory module Next
Memory How much RAM does an application require? p. 199 Depends on the types of software you plan to use For optimal  performance, you  need more than  minimum specifications Next
Memory How much RAM do you need? p. 200 Fig. 4-19 Depends on type of applications you intend to run on your computer Next RAM Use 512 MB to 1 GB 1 GB to 2 GB 2 GB and up Home and business users managing personal finances Using standard application software such as word processing Using educational  or entertainment CD-ROMs Communicating with others on the Web Users requiring more advanced multimedia capabilities Running number-intensive accounting, financial, or spreadsheet programs Using voice recognition Working with videos, music, and digital imaging Creating Web sites Participating in video conferences Playing Internet games Power users creating professional Web sites Running sophisticated CAD, 3D design, or other graphics-intensive software
Memory What is   cache ? p. 201 Fig. 4-20 L1 cache built into processor L2 cache slower but has larger capacity L2 advanced transfer cache is faster, built directly on processor chip L3 cache is separate from processor chip on motherboard (L3 is only  on computers that use L2 advanced transfer cache) Helps speed computer processes by storing frequently used instructions and data Also called   memory cache Next Click to view Web Link, click Chapter 4, Click  Web Link from left  navigation, then click  Cache below Chapter
Memory What is   read-only memory (ROM) ? p. 201 - 202 Memory chips that store  permanent data  and instructions Nonvolatile memory , it is not  lost when computer’s  power is turned off Three types: Firmware — Manufactured with  permanently written  data, instructions,  or information EEPROM  (electrically  erasable programmable  read-only memory)— Type of PROM  containing microcode  programmer  can erase PROM  (programmable  read-only  memory)— Blank ROM  chip onto which  a programmer  can write permanently Next
Memory What is   flash memory ? p. 202 Fig. 4-21 Step 1. Purchase and download music tracks from a Web site. With one end of a special cable connected to the system unit, connect the other end to the USB port in the portable media player. Step 2. Instruct the computer to copy the music tracks to the flash memory chip in the portable media player. Step 3. Plug the headphones into the portable media player, push a button on the portable media player, and listen to the music through the headphones. Nonvolatile memory that can be erased electronically and rewritten Used with PDAs, smart phones, printers, digital cameras, automotive devices, audio players, digital voice recorders, and pagers Next Click to view Web Link, click Chapter 4, Click Web Link from left navigation,  then click Flash Memory  below Chapter 4 MP3 Player flash memory chips USB port
Memory What is   CMOS ? p. 203 Next Uses battery  power to retain information when other power is turned off Stores date,  time, and  computer’s  startup  information C omplementary  m etal- o xide  s emiconductor memory Used in some  RAM chips, flash memory chips, and other types of memory chips
Memory What is   access time ? p. 203 Figs. 4-22-4-23 Amount of time it takes processor  to read data from memory Measured in  nanoseconds  (ns),  one billionth of a second It takes 1/10 of a second to blink  your eye; a computer can perform  up to 10 million operations in same amount of time Next Term Speed Millisecond One-thousandth of a second Microsecond One-millionth of a second Nanosecond One-billionth of a second Picosecond One-trillionth of a second
Expansion Slots and Adapter Cards What is an   adapter card ? p. 204 Fig. 4-24 Enhances system unit or provides connections to external devices called   peripherals Also called an   expansion card Next Click to view Web Link, click Chapter 4, Click Web Link from left navigation,  then click Sound Cards  below Chapter 4
Expansion Slots and Adapter Cards What is an   expansion slot ? p. 204 - 205 Fig. 4-25 An opening, or socket,  on the motherboard  that can hold an  adapter card With   Plug and Play ,  the computer  automatically  configures cards and other devices  as you install them Next
Expansion Slots and Adapter Cards What are   flash memory cards ,  PC cards , and  ExpressCard modules ? p. 205  Fig. 4-26–4-27 An   ExpressCard module  adds memory, storage, sound, fax/modem, communications, and other capabilities to notebook computers A   flash memory card   allows users to transfer data from mobile devices to desktop computers USB Flash drive An  PC card  adds various capabilities to computers Next Click to view Web Link, click Chapter 4, Click Web Link from left navigation,  then click ExpressCard Modules  below Chapter 4
Ports and Connectors What are   ports   and   connectors ? p. 206 Fig. 4-28 Port   connects external devices to system unit Connector  joins cable to peripheral Available in one of two genders: male and female Next
Ports and Connectors What are different types of connectors? p. 207 Fig. 4-29 Next
Ports and Connectors What is a   serial port ? p. 207 Fig. 4-30 Transmits one bit of data at a time Connects slow-speed devices, such as mouse, keyboard, modem Next
Ports and Connectors What is a   parallel port ? p. 208 Fig. 4-31 Connects devices that can transfer more than one bit at a time, such as a printer Next
Ports and Connectors What are   USB ports ? p. 208 USB  ( u niversal  s erial  b us)  port  can connect  up to 127 different peripherals together  with a single connector type USB 2.0 Third USB  device connects  to second USB  device, and so on Second USB  device connects  to first USB  device First USB  device connects  to USB port  on computer Single USB port can  be used to attach  multiple peripherals  in a daisy chain PCs typically have  six to eight USB ports  on front or back of  the system unit Next
Ports and Connectors What are   FireWire ports ? p. 209 Connects multiple types of devices that require faster data transmission speeds Allows you to connect up to 63 devices together Next Click to view Web Link, click Chapter 4, Click Web Link from left navigation,  then click FireWire Ports  below Chapter 4
Ports and Connectors What are   special-purpose ports? p. 209 - 210 Fig. 4-32 MIDI (Musical Instrument Digital Interface) port eSATA port SCSI port  IrDA (Infrared Data Association) port   Bluetooth port Allow users to attach specialized peripherals or transmit data to wireless devices  Next
Buses What is a   bus ? p. 211 - 212 Fig. 4-35 Channel that allows devices inside computer to communicate with each other System bus connects processor and RAM Bus width determines number of bits transmitted at one time Word size  is the number of  bits processor can interpret  and execute at a given time Next
Buses What is an   expansion bus? PC Card Bus p. 212 Allows processor to communicate with peripherals USB Bus PCI Bus PCI    Express Bus AGP Bus Next
Bays What is a   bay ? p. 212 Fig. 4-36 Opening inside system unit used to install additional equipment Drive bays   typically hold disk drives Next
Power Supply What is a  power supply ? p. 213 External peripherals might use an  AC adapter , which is an external power supply Next Converts AC Power into DC Power Fan keeps system unit components cool
Mobile Computers and Devices What is a   mobile computer? p. 213 - 214 Fig. 4-37 Notebook, weighing between 2.5 and 9 pounds, or mobile device such as a PDA Next
Mobile Computers and Devices What ports are on a notebook computer? p. 214 Fig. 4-38 Next
Mobile Computers and Devices What ports and slots are on a tablet PC? p. 214 Fig. 4-39 Next
Putting It All Together What are suggested processor and RAM configurations based on the needs of various types of users? p. 215 Fig. 4-40 Next
Keeping Your Computer Clean Over time, the system unit collects dust – even in a clean environment p. 216 Fig. 4-41 Preventative maintenance requires a few basic products:  Next
Summary of the Components of the System Unit Components of the system unit How memory stores data, instructions, and information Sequence of operations that occur when a computer executes an instruction Comparison of various personal computer processors on the market today Chapter 4 Complete How to clean a system unit

Chapter04

  • 1.
    Chapter 4 TheComponents of the System Unit
  • 2.
    Chapter 4 ObjectivesDifferentiate among various styles of system units Identify chips, adapter cards, and other components of a motherboard Describe the components of a processor and how they complete a machine cycle Identify characteristics of various personal computer processors on the market today Define a bit and describe how a series of bits represents data Explain how programs transfer in and out of memory Differentiate among the various types of memory Describe the types of expansion slots and adapter cards Explain the differences among a serial port, a parallel port, a USB port, a FireWire port, and other ports Describe how buses contribute to a computer’s processing speed Identify components in mobile computers and mobile devices Understand how to clean a system unit Next
  • 3.
    The System UnitWhat is the system unit ? p. 184 Fig. 4-1 Case that contains electronic components of the computer used to process data Sometimes called the chassis Next
  • 4.
    The System UnitWhat are common components inside the system unit? p. 185 Fig. 4-2 Memory Adapter cards Sound card Video card Drive bays Power supply Processor Next
  • 5.
    The System UnitWhat is the motherboard ? p. 186 Fig. 4-3 Main circuit board of the system unit Contains expansion slots, processor chips, and memory slots Also called system board Next Click to view Web Link, click Chapter 4, Click Web Link from left navigation, then click Motherboards below Chapter
  • 6.
    The System UnitWhat is a chip ? p. 186 Small piece of semi-conducting material on which integrated circuits are etched Integrated circuits contain many microscopic pathways capable of carrying electrical current Chips are packaged so they can be attached to a circuit board Next
  • 7.
    Processor What isthe central processing unit (CPU) ? Arithmetic Logic Unit (ALU) p. 187 - 188 Fig. 4-4 Input Devices Storage Devices Output Devices Interprets and carries out basic instructions that operate a computer Memory Data Information Control Unit Control unit directs and coordinates operations in computer Arithmetic logic unit (ALU) performs arithmetic, comparison, and logical operations Also called the processor Processor Control Unit Arithmetic Logic Unit (ALU) Next Instructions Data Information Instructions Data Information
  • 8.
    Processor What isa machine cycle? p. 188 Fig. 4-5 Step 1. Fetch Obtain program instruction or data item from memory Step 2. Decode Translate instruction into commands Step 4. Store Write result to memory Step 3. Execute Carry out command Four operations of the CPU comprise a machine cycle Processor Control Unit Memory ALU Next
  • 9.
    Processor What is pipelining? p. 189 Fig. 4-6 Processor begins fetching second instruction before completing machine cycle for first instruction Results in faster processing Next
  • 10.
    Processor What isa register? Stores location from where instruction was fetched Stores instruction while it is being decoded p. 189 Stores data while ALU computes it Stores results of calculation Temporary high-speed storage area that holds data and instructions Next
  • 11.
    Processor What isthe system clock ? p. 189 - 190 Each tick is a clock cycle Pace of system clock is clock speed Most clock speeds are in the gigahertz (GHz) range (1 GHz = one billion ticks of system clock per second) Processor speed can also be measured in millions of instructions per second (MIPS) Controls timing of all computer operations Generates regular electronic pulses, or ticks, that set operating pace of components of system unit Next
  • 12.
    Processor What are dual-core and multi-core processors ? p. 190 A dual-core processor is a single chip that contains two separate processors A multi-core processor is a chip with two or more separate processors Each processor on a dual-core/multi-core chip generally runs at a slower clock speed, but increase overall performance Next Click to view Web Link, click Chapter 4, Click Web Link from left navigation, then click Multi-Core Processors below Chapter 4
  • 13.
    Processor What arethe guidelines for selecting a processor? p. 192 Fig. 4-8 Next
  • 14.
    Processor What are heat sinks, heat pipes, and liquid cooling? p. 193 Fig. 4-9 Heat sink—component with fins that cools processor Heat pipe e —smaller device for notebook computers Liquid cooling—uses a continuous flow of fluids to transfer heat away Next
  • 15.
    Processor What is parallel processing? p. 194 Fig. 4-10 Control Processor Results combined Using multiple processors simultaneously to execute a program faster Requires special software to divide problem and bring results together Next Processor 1 Memory Processor 2 Memory Processor 3 Memory Processor 4 Memory
  • 16.
    Data Representation Howdo computers represent data? p. 194 - 195 Fig. 4-11 Recognize only two discrete states: on or off Use a binary system to recognize two states Use Number system with two unique digits: 0 and 1, called bits (short for binary digits) Most computers are digital Next
  • 17.
    Data Representation Whatis a byte ? p. 195 Fig. 4-12 Eight bits grouped together as a unit Provides enough different combinations of 0s and 1s to represent 256 individual characters Numbers Uppercase and lowercase letters Punctuation marks Other Next
  • 18.
    Data Representation Whatare three popular coding systems to represent data? p. 195 Fig. 4-13 ASCII—American Standard Code for Information Interchange EBCDIC—Extended Binary Coded Decimal Interchange Code Unicode—coding scheme capable of representing all world’s languages Next ASCII Symbol EBCDIC 00110000 0 11110000 00110001 1 11110001 00110010 2 11110010 00110011 3 11110011
  • 19.
    Data Representation Howis a letter converted to binary form and back? p. 196 Fig. 4-14 Step 3. The system unit converts the scan code for the capital letter T to its ASCII binary code (01010100) and stores it in memory for processing. Next Step 2. An electronic signal for the capital letter T is sent to the system unit. Step 4. After processing, the binary code for the capital letter T is converted to an image, and displayed on the output device. T Step 1. The user presses the capital letter T (SHIFT+T key) on the keyboard.
  • 20.
    Memory What is memory ? p. 197 Fig. 4-15 Electronic components that store instructions, data, and results Consists of one or more chips on motherboard or other circuit board Each byte stored in unique location called an address, similar to seats in a concert hall Next
  • 21.
    Memory How ismemory measured? p. 197 Fig. 4-16 By number of bytes available for storage Next Term Abbreviation Approximate Size Kilobyte KB or K 1 thousand bytes Megabyte MB 1 million bytes Gigabyte GB 1 billion bytes Terabyte TB 1 trillion bytes
  • 22.
    Memory What is random access memory ( RAM ) ? p. 198 - 199 The more RAM a computer has, the faster it responds Also called main memory or primary storage Most RAM is volatile, it is lost when computer’s power is turned off Memory chips that can be read from and written to by processor Next Click to view Web Link, click Chapter 4, Click Web Link from left navigation, then click RAM below Chapter
  • 23.
    Memory How doprogram instructions transfer in and out of RAM? p. 198 Fig. 4-17 Step 1. When you start the computer, certain operating system files are loaded into RAM from the hard disk. The operating system displays the user interface on the screen. Operating system instructions Web browser instructions Paint program instructions Operating system interface Web browser window Paint program window Web browser program instructions are removed from RAM Web browser window is no longer displayed on desktop Step 2. When you start a Web browser, the program’s instructions are loaded into RAM from the hard disk. The Web browser window is displayed on the screen. Step 3. When you start a paint program, the program’s instructions are loaded into RAM from the hard disk. The paint program, along with the Web Browser and certain operating system instructions are in RAM. The paint program window is displayed on the screen. Step 4. When you quit a program, such as the Web browser, its program instructions are removed from RAM. The Web browser is no longer displayed on the screen. Next RAM RAM
  • 24.
    Memory Video: TheLeopard with a Time Machine Next CLICK TO START
  • 25.
    Memory What aretwo basic types of RAM chips? p. 199 Static RAM (SRAM) Dynamic RAM (DRAM) Newer Type: Magnetoresistive RAM (MRAM) Must be re-energized constantly Do not have to be re-energized as often as DRAM Most common type Faster and more reliable than DRAM chips Next
  • 26.
    Memory Where doesmemory reside? p. 199 Fig. 4-18 Resides on small circuit board called memory module Memory slots on motherboard hold memory modules memory chip memory slot dual inline memory module Next
  • 27.
    Memory How muchRAM does an application require? p. 199 Depends on the types of software you plan to use For optimal performance, you need more than minimum specifications Next
  • 28.
    Memory How muchRAM do you need? p. 200 Fig. 4-19 Depends on type of applications you intend to run on your computer Next RAM Use 512 MB to 1 GB 1 GB to 2 GB 2 GB and up Home and business users managing personal finances Using standard application software such as word processing Using educational or entertainment CD-ROMs Communicating with others on the Web Users requiring more advanced multimedia capabilities Running number-intensive accounting, financial, or spreadsheet programs Using voice recognition Working with videos, music, and digital imaging Creating Web sites Participating in video conferences Playing Internet games Power users creating professional Web sites Running sophisticated CAD, 3D design, or other graphics-intensive software
  • 29.
    Memory What is cache ? p. 201 Fig. 4-20 L1 cache built into processor L2 cache slower but has larger capacity L2 advanced transfer cache is faster, built directly on processor chip L3 cache is separate from processor chip on motherboard (L3 is only on computers that use L2 advanced transfer cache) Helps speed computer processes by storing frequently used instructions and data Also called memory cache Next Click to view Web Link, click Chapter 4, Click Web Link from left navigation, then click Cache below Chapter
  • 30.
    Memory What is read-only memory (ROM) ? p. 201 - 202 Memory chips that store permanent data and instructions Nonvolatile memory , it is not lost when computer’s power is turned off Three types: Firmware — Manufactured with permanently written data, instructions, or information EEPROM (electrically erasable programmable read-only memory)— Type of PROM containing microcode programmer can erase PROM (programmable read-only memory)— Blank ROM chip onto which a programmer can write permanently Next
  • 31.
    Memory What is flash memory ? p. 202 Fig. 4-21 Step 1. Purchase and download music tracks from a Web site. With one end of a special cable connected to the system unit, connect the other end to the USB port in the portable media player. Step 2. Instruct the computer to copy the music tracks to the flash memory chip in the portable media player. Step 3. Plug the headphones into the portable media player, push a button on the portable media player, and listen to the music through the headphones. Nonvolatile memory that can be erased electronically and rewritten Used with PDAs, smart phones, printers, digital cameras, automotive devices, audio players, digital voice recorders, and pagers Next Click to view Web Link, click Chapter 4, Click Web Link from left navigation, then click Flash Memory below Chapter 4 MP3 Player flash memory chips USB port
  • 32.
    Memory What is CMOS ? p. 203 Next Uses battery power to retain information when other power is turned off Stores date, time, and computer’s startup information C omplementary m etal- o xide s emiconductor memory Used in some RAM chips, flash memory chips, and other types of memory chips
  • 33.
    Memory What is access time ? p. 203 Figs. 4-22-4-23 Amount of time it takes processor to read data from memory Measured in nanoseconds (ns), one billionth of a second It takes 1/10 of a second to blink your eye; a computer can perform up to 10 million operations in same amount of time Next Term Speed Millisecond One-thousandth of a second Microsecond One-millionth of a second Nanosecond One-billionth of a second Picosecond One-trillionth of a second
  • 34.
    Expansion Slots andAdapter Cards What is an adapter card ? p. 204 Fig. 4-24 Enhances system unit or provides connections to external devices called peripherals Also called an expansion card Next Click to view Web Link, click Chapter 4, Click Web Link from left navigation, then click Sound Cards below Chapter 4
  • 35.
    Expansion Slots andAdapter Cards What is an expansion slot ? p. 204 - 205 Fig. 4-25 An opening, or socket, on the motherboard that can hold an adapter card With Plug and Play , the computer automatically configures cards and other devices as you install them Next
  • 36.
    Expansion Slots andAdapter Cards What are flash memory cards , PC cards , and ExpressCard modules ? p. 205 Fig. 4-26–4-27 An ExpressCard module adds memory, storage, sound, fax/modem, communications, and other capabilities to notebook computers A flash memory card allows users to transfer data from mobile devices to desktop computers USB Flash drive An PC card adds various capabilities to computers Next Click to view Web Link, click Chapter 4, Click Web Link from left navigation, then click ExpressCard Modules below Chapter 4
  • 37.
    Ports and ConnectorsWhat are ports and connectors ? p. 206 Fig. 4-28 Port connects external devices to system unit Connector joins cable to peripheral Available in one of two genders: male and female Next
  • 38.
    Ports and ConnectorsWhat are different types of connectors? p. 207 Fig. 4-29 Next
  • 39.
    Ports and ConnectorsWhat is a serial port ? p. 207 Fig. 4-30 Transmits one bit of data at a time Connects slow-speed devices, such as mouse, keyboard, modem Next
  • 40.
    Ports and ConnectorsWhat is a parallel port ? p. 208 Fig. 4-31 Connects devices that can transfer more than one bit at a time, such as a printer Next
  • 41.
    Ports and ConnectorsWhat are USB ports ? p. 208 USB ( u niversal s erial b us) port can connect up to 127 different peripherals together with a single connector type USB 2.0 Third USB device connects to second USB device, and so on Second USB device connects to first USB device First USB device connects to USB port on computer Single USB port can be used to attach multiple peripherals in a daisy chain PCs typically have six to eight USB ports on front or back of the system unit Next
  • 42.
    Ports and ConnectorsWhat are FireWire ports ? p. 209 Connects multiple types of devices that require faster data transmission speeds Allows you to connect up to 63 devices together Next Click to view Web Link, click Chapter 4, Click Web Link from left navigation, then click FireWire Ports below Chapter 4
  • 43.
    Ports and ConnectorsWhat are special-purpose ports? p. 209 - 210 Fig. 4-32 MIDI (Musical Instrument Digital Interface) port eSATA port SCSI port IrDA (Infrared Data Association) port Bluetooth port Allow users to attach specialized peripherals or transmit data to wireless devices Next
  • 44.
    Buses What isa bus ? p. 211 - 212 Fig. 4-35 Channel that allows devices inside computer to communicate with each other System bus connects processor and RAM Bus width determines number of bits transmitted at one time Word size is the number of bits processor can interpret and execute at a given time Next
  • 45.
    Buses What isan expansion bus? PC Card Bus p. 212 Allows processor to communicate with peripherals USB Bus PCI Bus PCI Express Bus AGP Bus Next
  • 46.
    Bays What isa bay ? p. 212 Fig. 4-36 Opening inside system unit used to install additional equipment Drive bays typically hold disk drives Next
  • 47.
    Power Supply Whatis a power supply ? p. 213 External peripherals might use an AC adapter , which is an external power supply Next Converts AC Power into DC Power Fan keeps system unit components cool
  • 48.
    Mobile Computers andDevices What is a mobile computer? p. 213 - 214 Fig. 4-37 Notebook, weighing between 2.5 and 9 pounds, or mobile device such as a PDA Next
  • 49.
    Mobile Computers andDevices What ports are on a notebook computer? p. 214 Fig. 4-38 Next
  • 50.
    Mobile Computers andDevices What ports and slots are on a tablet PC? p. 214 Fig. 4-39 Next
  • 51.
    Putting It AllTogether What are suggested processor and RAM configurations based on the needs of various types of users? p. 215 Fig. 4-40 Next
  • 52.
    Keeping Your ComputerClean Over time, the system unit collects dust – even in a clean environment p. 216 Fig. 4-41 Preventative maintenance requires a few basic products: Next
  • 53.
    Summary of theComponents of the System Unit Components of the system unit How memory stores data, instructions, and information Sequence of operations that occur when a computer executes an instruction Comparison of various personal computer processors on the market today Chapter 4 Complete How to clean a system unit