Chapter 4 Objectives
Describe the components Describe the types of expansion slots and cards in the system unit in the system unit Explain how the CPU uses the Explain the difference between four steps of a machine cycle a serial, a parallel, to process data and a USB port Compare and contrast various Describe how buses Chapter 4 personal computer processors contribute to a computer’s The Components of on the market today processing speed Define a bit and describe how a Identify components the System Unit series of bits represents data in a notebook computer
Differentiate among the Identify components various types of memory in a handheld computer
Next p. 4.2
The System Unit The System Unit What is the system unit? What are common components inside • Box-like case that the system unit? contains computer’s Processor electronic Memory module components Expansion cards • Sometimes called the • Sound card chassis • Modem card • Video card • Network interface card Ports and Next Next Connectors p. 4.2 Fig. 4-1 p. 4.3 Fig. 4-2
The System Unit The System Unit
What is the motherboard? What chip packages are available? Main circuit board
in system unit expansion cards Contains memory module dual inline package (DIP) (RAM chips) chips, single edge contact (SEC) cartridge integrated circuits, heat sink and transistors memory slots expansion slots Also called system board processor chip flip chip-PGA (FC-PGA) package Next Next p. 4.4 Fig. 4--3 p. 4.4 Fig. 4-4 pin grid array (PGA)
1 Central Processing Unit Central Processing Unit
What is the central processing unit (CPU) ? What are the components of the Interprets and carries out basic instructions that operate a computer CPU? Also called the processor CPU CPU Control Arithmetic/ Unit Logic Unit (ALU)
Next Next p. 4.5 Fig. 4-5 p. 4.5
Central Processing Unit Central Processing Unit
What is the control unit? What is a machine cycle? Directs and coordinates Four operations of the CPU comprise a machine cycle operations in computer Also called instruction cycle Control unit repeats • Instruction time (i-time) - time taken to fetch and decode four basic operations: • Execution time (e-time) - time taken to execute and store Fetch - obtain program instruction or Control Unit data item from memory e-time i-time Decode - translate instruction into commands Execute - carry out command Store - write result to memory
Next Next p. 4.5 p. 4.6
Central Processing Unit Central Processing Unit
An example of a 100 x 52 How is the CPU’s speed machine cycle measured? According to how Student enters many millions of math problem instructions per (100 x 52) into computer’s second (MIPS) it memory can process Result in memory displays on monitor’s screen Next Next p. 4.6 Fig. 4-6 p. 4.6
2 Central Processing Unit Central Processing Unit
What are two designs used for the CPU? What is the arithmetic/logic unit (ALU) ? •CPU component Comparison CISC that performs (greater than, equal (complex instruction set execution to, or less than) computing) RISC part of the (reduced instruction Supports large number machine .. of instructions set computing) cycle nd .a CPU executes complex Supports smaller .a instructions more number of r.. ..no instructions ..o ot.. quickly Arithmetic Logical CPU executes simple (addition, subtraction, (AND, OR, instructions more Next Next multiplication, and NOT) p. 4.6 quickly p. 4.7 division)
Central Processing Unit Central Processing Unit
What is pipelining? What is a register? CPU begins executing second instruction before Temporary completing first instruction storage area Results in faster processing that holds Machine Cycle (without pipelining) Stores Stores results data and instruction of calculation instructions while it is being decoded Machine Cycle (with pipelining)
Instruction 1 Stores location Stores data while Instruction 2 from where instruction was ALU processes it Instruction 3 Next Next fetched p. 4.7 Fig. 4-7 Instruction 4 p. 4.7
Central Processing Unit Central Processing Unit
What is the system clock? What is a microprocessor? Single processor chip found Synchronizes all computer in personal computers operations Each tick is clock cycle
MHz - one million ticks of system clock
Next GHz – one billion ticks Next p. 4.8 of system clock p. 4.9
3 Central Processing Unit Central Processing Unit
What is a coprocessor? How do personal computer processors Chip that assists compare? processor in performing specific tasks One type is a floating-point coprocessor, also known as a
Next Next math or numeric p. 4.9 Fig. 4-10 p. 4.13 coprocessor
Central Processing Unit Data Representation
What is parallel processing? How do computers represent data? Using multiple processors simultaneously to execute Most computers are digital program faster Recognize only two discrete states: on or off
on 11111
Requires special software to divide problem and bring off 00 000 Next Next p. 4.13 Fig. 4-13 results together p. 4.13
Data Representation Data Representation
What is the binary system? What is a byte? Eight bits grouped together Number system with two unique digits: 0 and 1
8-bit byte for the number 3 Binary Electronic Electronic Digit (bit) Charge State
8-bit byte for the number 5
8-bit byte for the capital letter T
Next Next p. 4.14 Fig. 4-14 p. 4.14 Fig. 4-15
4 Data Representation Data Representation
What are three popular coding systems to How is a character sent from keyboard to represent data? computer? Step 1: Press letter T ASCII - American
Standard Code for Step 2: Electronic signal for letter Information Interchange T sent to system unit
EBCDIC - Extended Step 3: Signal changed to its Binary Coded Decimal ASCII code (01010100) and stored Interchange Code in memory
Unicode -coding Step 4: After processing, binary scheme capable of code for letter T is converted to representing all world’s image on output device languages
Next Next p. 4.14 Fig. 4-16 p. 4.15 Fig. 4-17
Memory Memory
What is memory? How is memory measured? By number of bytes available Temporary storage area for operating system, application programs, seat A22 seat C22 and data seat B22 Consists of one or more chips on motherboard Each byte stored in unique address
Next Next p. 4.15 p. 4.16 Fig. 4-19
Memory Memory
What are two types of system unit memory? What is random access memory (RAM)? Memory chips that can be read from and written to by processor Most RAM is volatile The more RAM a computer has, the faster it volatile memory operates Loses its contents when nonvolatile thecomputer's computer's power power is memory isturned turned off off Does NOT lose its contents when computer’s power is memory module Next turned off Next p. 4.16 p. 4.16
5 Memory Memory
What are two basic types of RAM chips? How much RAM is needed?
Dynamic RAM (DRAM) Software package usually indicates Most common type RAM requirements Also called main memory Static RAM (SRAM) Used for special applications such as cache Faster and more reliable than DRAM Next Next p. 4.18 chips p. 4.18 Fig. 4-22
Memory Memory
How much RAM is needed? What is cache? Depends on type of applications you intend to run Helps speed computer on your computer processes by storing frequently used instructions and data Also called memory cache, cache store, or RAM cache L1 cache built in processor L2 and L3 cache not built in processor L2 advanced transfer cache most common
Next Next p. 4.19 Fig. 4-23 p. 4.20 Fig. 4-24
Memory Memory
What is read-only memory (ROM)? Types of ROM
Memory chips that contain data, instructions, or Firmware information that is recorded permanently ROM chips manufactured with PROM permanently (programmable EEPROM written data, BIOS read-only instructions, or (electrically Data can only ROM is (basic input/output system) memory) information erasable be read; nonvolatile — Stored on ROM Blank ROM on programmable read- cannot be Contents not lost Sequence of instructions which you can only memory) modified in when computer is computer follows to load place items Type of PROM ROM turned off operating system and other files when you turn on the permanently containing computer microcode
Next Next programmer can p. 4.20 p. 4.20 erase
6 Memory Memory
What is flash memory? What is CMOS? Nonvolatile memory that can be erased electronically and reprogrammed Used with handheld computers and digital cameras, Complementary cellular phones, and automobiles metal-oxide semiconductor Stores memory information about the computer Uses battery • type of disk drives to retain • keyboard information • monitor when • current time and date computer is Next Next turned off p. 4.21 Fig. 4-25 p. 4.21
Memory Expansion Slots and Expansion Cards What is memory access What is an expansion slot? time? Speed at which processor can access An opening, or data from memory directly socket, where Measured in nanoseconds (ns), which is circuit board is one billionth of a second inserted into It takes 1/10 of a second to blink your eye; a computer motherboard can perform up to 10 million operations in same Expansion card amount of time inserted in expansion slot
expansion card Next Next p. 4.22 Fig. 4-26 & 27 p. 4.23 Fig. 4-29 expansion slot
Expansion Slots and Expansion Slots and Expansion Cards Expansion Cards
How are What is Plug and Play? expansion cards Computer used? automatically can configure cards and other devices as you install them
Next Next p. 4.23 Fig. 4-28 p. 4.24 Fig. 4-29
7 Expansion Slots and Expansion Slots and Expansion Cards Expansion Cards What is a PC card? What is a flash
Credit card-sized device memory card? used to add capabilities to Adds memory to notebook computers handheld computers, PCMCIA - Personal digital music players, Computer Memory Card cellular telephones, International Association and similar devices Uses include modem, additional memory, and storage
Next Next p. 4.24 Fig. 4-30 PC card p. 4.25 Fig. 4-31
Ports Ports
mouse What is a port? keyboard What are different types of connectors? USB USB Connects external serial port printer (parallel devices to port)
system unit speaker monitor microphone
network
telephone telephone line line out in Next Next svideo out FM reception p. 4.25 Fig. 4-32 p. 4.26 Fig. 4-34 cable TV
Ports byte Ports serial representation byte representation for transmission for number 5 number 1 of data (00110101) What is a parallel What is a serial port? byte representation for byte port? number 3 representation byte representation for Transmits one bit of for number 5 number 5 (00110101) byte Connects devices data at a time representation that can transfer for number 5 Used to connect slow- (00110101) more than one bit at speed devices, such a time, such as a as mouse, keyboard, printer modem
DB-9 female DB-25 male connector connector
Next Next p. 4.27 Fig. 4-35 DB-9 male p. 4.27 Fig. 4-36 DB-25 female connector connector
8 Ports Buses
What is a universal serial bus port (USB) ? What is a bus? Channel that allows devices inside Connector that computer to communicate with each supports newer other peripherals and plug and play System bus connects processor and processor RAM system Other popular bus ports include Bus width determines number 1394, MIDI, of bits transmitted at one time SCSI, and IrDA Word size determines number of bits processor can interpret and execute at a given time 1394 port
Next Next p. 4.28 Fig. 4-37 USB port p. 4.29 Fig. 4-39 RAM
Buses Bays
DVD-ROM What is an expansion bus? What is a bay? drive Allows processor to communicate with peripherals Open area inside CD-RW drive fastest memory system unit used next fastest Zip drive next fastest to install additional slowest equipment empty drive processor bay floppy disk drive
Next PCI bus Next p. 4.31 Fig. 4-41 expansion slots ISA bus expansion slots p. 4.32 Fig. 4-42
Power Supply Mobile Computers
What is a mobile computer? What is a power supply? system unit Notebook, which weighs on handheld between 2.5 and 8 computer Some pounds, or handheld Converts peripheral alternating devices have current (AC) to AC adapter direct current (DC) PC Cards in PC Card CD-ROM or slots DVD-ROM Floppy disk drive drive or Zip Next Next disk drive battery p. 4.32 p. 4.33 Fig. 4-43 system unit on notebook computer
9 Mobile Computers Mobile Computers
What ports are on a notebook computer? How is data transferred from a handheld computer? IrDA port An IrDA port allows the handheld computer to communicate wirelessly with other computers or devices Handheld computers also can keyboard/mouse rest in a cradle, so you can cradle port transfer data to your desktop computer IrDA port USB port serial port parallel video port Next port Next p. 4.34 Fig. 4-45 p. 4.34 Fig. 4-46
Putting It All Together
What are suggested processor, clock speed, and Summary of the Components RAM requirements based on the needs of various of the System Unit types of users? • The system unit Home Mobile Pentium® 4 or Pentium® III or • Central processing unit Athlon™ 600 AMD-K6®Power -2-P 500 MHz or higher; MHz or higher • Data representation or Celeron™ or 64 MB RAM Duron™ 600 • Memory MHz or higher Pentium® 4 or Large Small Office/Home Office 64 MB RAM Athlon™ 700 • Expansion slots and expansion cards Business MHz or higher • Ports, buses, bays Pentium® 4 or 128 MB RAM Athlon™ 800 Pentium® 4 or • Power supply MHz or higher Itanium™ or 128 MB RAM Athlon™ 1 GHz • Mobile computers Next or higher Next p. 4.35 Fig. 4-47 256 MB RAM Chapter 4 Complete
10