SlideShare ist ein Scribd-Unternehmen logo
1 von 53
Downloaden Sie, um offline zu lesen
The System Unit
The system unit is a case that contains electronic
components of the computer used to process data.
 System units are available in a variety of shapes
and sizes.
 The case of the system unit, sometimes called
 the chassis, is made of metal or plastic and
  protects
the internal electronic components from damage.
 All computers and mobile devices have a system
Unit.
The system unit
The Motherboard
 The motherboard, sometimes called a system
board, is the main circuit board of the system unit.
 Many electronic components attach to the
Motherboard, others are built into it.
Processor
 The processor, also called the central processing unit
   (CPU), interprets and carries out the basic
   instructions that operate a computer.
  The processor significantly impacts overall computing
   power and manages most of a computer’s operations.
  Most processor chip manufacturers now offer multi-
   core processors. A processor core, or simply
   core, contains the circuitry necessary to execute
   instructions.
  Processors contain a control unit and an arithmetic
   logic unit (ALU).
  These two components work together to perform
   processing operations.
The Control Unit
The control unit is the component of
the processor that directs and coordinates
most of the operations in the computer.
 it interprets each instruction issued by
a program and then initiates the appropriate
action to carry out the instruction.
 Types of internal components that the control
unit directs include the arithmetic/logic unit ,
 registers, and buses.
The Arithmetic Logic Unit
The arithmetic logic unit (ALU), another
   component of
the processor, performs arithmetic, comparison,
   and
Other operations.
 Arithmetic operations include basic calculations
   such as
addition, subtraction, multiplication, and division.
 Comparison operations involve comparing one
   data
item with another to determine whether the first
   item
Machine Cycle
For every instruction, a processor repeats a
set of four basic operations, which comprise
a machine cycle
(1) fetching
(2) Decoding
 (3) executing
(4) storing
• Fetching is the process of obtaining a program
instruction or data item from memory.

• Decoding refers to the process of translating
the instruction into signals the computer can
execute.

• Executing is the process of carrying out the
commands.

• Storing, in this context, means writing the result
to memory (not to a storage medium).
The system unit
Registers
A processor contains small, high-speed storage
locations, called registers, that temporarily hold
data and instructions.
 Registers are part of the processor, not part of
memory or a permanent storage device.
 Processors have many different types of
registers, each with a specific storage function.
The System Clock
The processor relies on a small quartz crystal
circuit called the system clock to control the
timing of all computer operations.
the system clock generates regular electronic
pulses, or ticks, that set the operating pace of
components of the system unit.
Each tick equates to a clock cycle The pace of the
system clock, called the clock speed, is
  measured
by the number of ticks per second
Processor Cooling
 Heat sinks
pipes and liquid cooling technologies often are
  used to help dissipate processor heat.
 A heat sink is a small ceramic or metal
  component with fins on its surface that absorbs
  and disperses heat produced by electrical
  components such as a processor .
Heat Sinker
Parallel Processing
 Parallel processing is a method that uses multiple
 processors simultaneously to execute a single
 program or task .
Parallel Processing
Memory
• Memory consists of electronic components
that store instructions waiting to be executed.
• Memory stores three basic categories of items
  1-: the operating system and other
• system software that control or maintain the computer
  and its devices .
2-:application programs
that carry out a specific task such as
word processing .
 3-:The data being processed
by the application programs and resulting
information.
Memory Sizes

 1 Kilobyte = 1,024
 1 Megabyte =1,048,576
 1 Gigabyte =1,073,741,824
 1 Terabyte =1,099,511,627,776
Types of Memory
 volatile memory
 Nonvolatile memory
Types of Memory
 RAM (random access memory), also called main
 memory, consists of memory chips that can be
 read from and written to by the processor and
 other devices.
Types of Memory
  TWO basic types of RAM
 1-: Dynamic RAM
 2-:Static RAM
memory modules
 There are three types of memory modules.
1-:SIMMs(single inline memory module)
2-:DIMMs(dual inline memory module)
3-:RIMMs(Rambus inlinememory module)
MEMORY MODULES
Types of Memory
 Cache Memory
                   Cache Memory helps speed
 the processes of the computer because it stores
 frequently used instructions and data.
types of memory cache
 L1 cache
 L2 cache
types of memory cache
• L1 cache
             L1 cache usually has a very small
  capacity ranging from 8 KB to 128 KB. The more
common sizes for personal computers are
32 KB or 64 KB.
• L2 cache
              L2 cache is slightly slower than L1
  cache but has a much larger capacity, ranging
  from 64 KB to 16 MB.
Types of Memory
 ROM(Read only memory)
                             ROM is nonvolatile,
  which means its contents are not lost when power
is removed from the computer. In addition to
computers, many devices contain ROM chips.
For example, ROM chips in printers contain
data for fonts.
TYPES OF ROM
 There are two types of ROM
1-:PROM
2-:EEPROM
TYPES OF ROM
• PROM (programmable read-only memory)
         A PROM chip is a blank ROM chip on
  which a programmer can write permanently.
  Programmers use microcode instructions to
  program a PROM
  chip.
Once a programmer writes the microcode
on the PROM chip, it functions like a
regular ROM chip and cannot be erased or
changed.
TYPES OF ROM
 EEPROM (electrically erasable programmable
 read-only memory)
                      EEPROM chip, allows a
 programmer to erase the microcode with an
 electric signal.
Types of Memory
 Flash Memory
                   Flash memory is a type of
 nonvolatile memory that can be erased
 electronically and rewritten, similar to EEPROM.
Types of Memory
•   CMOS(complementary metal-oxide semiconductor)

 (CMOS pronounced SEE-moss) technology because it provides high
  speeds and
consumes little power.

 CMOS technology uses battery power to retain information even
when the power to the computer is off.

 Battery-backed CMOS memory chips, for example, can keep the
calendar, date, and time current even when the computer is off.

 The flash memory chips that store a computer’s startup information
often use CMOS technology.
Memory Access Times
 Access time is the amount of time it takes
the processor to read data, instructions, and
information from memory.
A computer’s access time directly affects how
fast the computer processes data.
Expansion Slots and Adapter
Cards
• Expansion Slots
                   An expansion slot is a
 socket on the motherboard that can hold an
 adapter card.

• Adapter Cards
               An adapter card, sometimes called
 an expansion card, is a circuit board that
 enhances functions of a component of the system
 unit and/or provides connections to peripherals.
ADAPTER CARD
Removable Flash Memory
 A type of memory which can easily insert and
  remove from a slot of a personal computer.
 A memory card is a removable flash memory
  device, usually no bigger than 1.5" in height or
width, that you insert and remove from a slot
in a personal computer, game console, mobile
device, or card reader/writer.
Removable Flash Memory
Ports and Connectors
• PORTS
  A port is the point at which a peripheral
  attaches
to or communicates with a system unit so that the
peripheral can send data to or receive information
from the computer.
• CONNECTORS
A connector joins a cable to a port. A connector
at one end of a cable attaches to a port on the
  system unit, and a connector at the other end of
the cable attaches to a port on the peripheral.
Ports and Connectors
Ports and Connectors
• USB Ports
              A USB port, short for universal
 serial bus port, can connect up to 127 different
 peripherals together with a single connector.
 Devices that connect to a USB port include the
 following:
mouse, printer, digital camera, scanner, speakers,
portable media player, optical disc drive, smart
phone, PDA, game console, and removable
hard disk.
Ports and Connectors
 FireWire Ports
                       FireWire port is similar to a
  USB port in that it can connect multiple types of
  devices that require faster data transmission
  speeds such as digital video cameras, digital
  VCRs,
color printers, scanners, digital cameras, and
DVD drives, to a single connector.
Ports and Connectors
 Bluetooth Port
                    Bluetooth technology uses
  radio waves to transmit data between two
devices.
A Bluetooth wireless port adapter that will convert
  an existing USB port into a Bluetooth port .
BLUETOOTH DEVICE
Ports and Connectors
 SCSI Port
              A special high-speed parallel port
 called a SCSI port, allows you to attach
 SCSI(pronounced skuzzy) peripherals such as
 disk drives and printers.
Ports and Connectors
• eSATA Port
•         An eSATA port, or external SATA
  port, allows you to connect an external SATA
  (Serial Advanced Technology Attachment) hard
  disk to a computer.
  SATA hard disks are popular because of their fast
  data transmission speeds.
• eSATA connections provide up to six times faster
  data transmission speeds than external hard
  disks attached to a computer’s USB or FireWire
  port .
Ports and Connectors
 IrDA Port
                  IrDA port is used infrared signals to
    transmit data one device to another device.
    Devices that use IrDA ports include a smart
    phone, PDA, keyboard, mouse, and printer.
    Several of these devices use a high-speed IrDA
    port, sometimes called a fast infrared port.
IrDA ports
Ports and Connectors
• Serial Ports
          A serial port is a type of interface that
  connects a device to the system unit by
  transmitting data one bit at a time.
• MIDI Port
          A special type of serial port that
connects the system unit to a musical instrument
  , such as an electronic keyboard, is called a MIDI
  port.
Port Replicators and Docking
Stations
 Port Replicators
 A port replicator is an external device
that provides connections to peripherals through
  ports built into the device. The mobile user
  accesses peripherals by connecting the port
  replicator to a USB port or a special port on the
  mobile computer.
Buses
 Buses are used to transfer bits from input
  devices to memory, from memory to the
 processor, from the processor to memory, and
 from memory to output or storage devices.
BUSES
PARTS OF BUSES
• There are two parts of buses
• DATA BUS
• ADDRESS BUS
1-:Data Bus
              The data bus is used to transfer
  actual data.
2-:Address Bus
•           The address bus is used to transfer
  information about where the data should reside in
memory.
TYPES OF BUSES
• There three types of buses
• System Bus
• Backside Bus
• Expansion Bus
1-:System Bus
•                   A system bus, also called the
front side bus ( FSB), is part of the motherboard
and connects the processor to main memory.
TYPES OF BUSES
2-:Backside Bus
             A backside bus ( BSB) connects the
  processor to cache.
3-:Expansion Bus
             An expansion bus allows the
  processor to communicate with peripherals.

Weitere ähnliche Inhalte

Was ist angesagt?

Computer capabilities limitations
Computer capabilities limitationsComputer capabilities limitations
Computer capabilities limitationsJesus Obenita Jr.
 
Presentation on C.P.U
Presentation on C.P.UPresentation on C.P.U
Presentation on C.P.Ufgdgxvbm98
 
CPU-Central Processing Unit (With History and Complete Detail)
CPU-Central Processing Unit (With History and Complete Detail)CPU-Central Processing Unit (With History and Complete Detail)
CPU-Central Processing Unit (With History and Complete Detail)Adeel Rasheed
 
1 01 Computer Components
1 01 Computer Components1 01 Computer Components
1 01 Computer Componentsjasonmammano
 
Parts of a Computer
Parts of a ComputerParts of a Computer
Parts of a ComputerMatt Shea
 
Functioning of computer
Functioning of computerFunctioning of computer
Functioning of computerSunipa Bera
 
01. Basics of Computer Hardware
01. Basics of Computer Hardware01. Basics of Computer Hardware
01. Basics of Computer HardwareAkhila Dakshina
 
Cpu presentation
Cpu presentationCpu presentation
Cpu presentationHarry Singh
 
Computer Hardware Basics
Computer Hardware BasicsComputer Hardware Basics
Computer Hardware BasicsMark Rotondella
 
Storage devices in computer systems
Storage devices in computer systemsStorage devices in computer systems
Storage devices in computer systemsKevin Philip Joseph
 
Motherboard, It's Functions and It's Components
Motherboard, It's Functions and It's ComponentsMotherboard, It's Functions and It's Components
Motherboard, It's Functions and It's ComponentsPreSolutions Softwares
 
COMPUTER MEMORY : TYPES & FUNCTIONS
COMPUTER MEMORY : TYPES & FUNCTIONSCOMPUTER MEMORY : TYPES & FUNCTIONS
COMPUTER MEMORY : TYPES & FUNCTIONSAngel Mary George
 
Types of memory in Computer
Types of memory in ComputerTypes of memory in Computer
Types of memory in ComputerFazle Rabbi Ador
 
Fundamental of computer
Fundamental of computerFundamental of computer
Fundamental of computerstudent
 
CPU Architecture - Basic
CPU Architecture - BasicCPU Architecture - Basic
CPU Architecture - BasicYong Heui Cho
 
Computer System Hardware
Computer System HardwareComputer System Hardware
Computer System HardwareRCKSTR
 

Was ist angesagt? (20)

Computer capabilities limitations
Computer capabilities limitationsComputer capabilities limitations
Computer capabilities limitations
 
Presentation on C.P.U
Presentation on C.P.UPresentation on C.P.U
Presentation on C.P.U
 
CPU-Central Processing Unit (With History and Complete Detail)
CPU-Central Processing Unit (With History and Complete Detail)CPU-Central Processing Unit (With History and Complete Detail)
CPU-Central Processing Unit (With History and Complete Detail)
 
1 01 Computer Components
1 01 Computer Components1 01 Computer Components
1 01 Computer Components
 
Parts of a Computer
Parts of a ComputerParts of a Computer
Parts of a Computer
 
How the cpu works
How the cpu worksHow the cpu works
How the cpu works
 
Functioning of computer
Functioning of computerFunctioning of computer
Functioning of computer
 
OPERATING SYSTEM
OPERATING SYSTEMOPERATING SYSTEM
OPERATING SYSTEM
 
cpu-200816132241.pdf
cpu-200816132241.pdfcpu-200816132241.pdf
cpu-200816132241.pdf
 
01. Basics of Computer Hardware
01. Basics of Computer Hardware01. Basics of Computer Hardware
01. Basics of Computer Hardware
 
Cpu presentation
Cpu presentationCpu presentation
Cpu presentation
 
Computer Hardware Basics
Computer Hardware BasicsComputer Hardware Basics
Computer Hardware Basics
 
Storage devices in computer systems
Storage devices in computer systemsStorage devices in computer systems
Storage devices in computer systems
 
Motherboard, It's Functions and It's Components
Motherboard, It's Functions and It's ComponentsMotherboard, It's Functions and It's Components
Motherboard, It's Functions and It's Components
 
The Motherboard
The MotherboardThe Motherboard
The Motherboard
 
COMPUTER MEMORY : TYPES & FUNCTIONS
COMPUTER MEMORY : TYPES & FUNCTIONSCOMPUTER MEMORY : TYPES & FUNCTIONS
COMPUTER MEMORY : TYPES & FUNCTIONS
 
Types of memory in Computer
Types of memory in ComputerTypes of memory in Computer
Types of memory in Computer
 
Fundamental of computer
Fundamental of computerFundamental of computer
Fundamental of computer
 
CPU Architecture - Basic
CPU Architecture - BasicCPU Architecture - Basic
CPU Architecture - Basic
 
Computer System Hardware
Computer System HardwareComputer System Hardware
Computer System Hardware
 

Ähnlich wie The system unit

Components of the System Unit.pdf
Components of the System Unit.pdfComponents of the System Unit.pdf
Components of the System Unit.pdfODINARARCH
 
3. Component of computer - System Unit ( CSI-321)
3. Component of computer - System Unit  ( CSI-321) 3. Component of computer - System Unit  ( CSI-321)
3. Component of computer - System Unit ( CSI-321) ghayour abbas
 
Computer - Hardware components
Computer -  Hardware componentsComputer -  Hardware components
Computer - Hardware componentsComputer Science
 
Lecture 2 - Computer Hardware & Operating Systems
Lecture 2 - Computer Hardware & Operating SystemsLecture 2 - Computer Hardware & Operating Systems
Lecture 2 - Computer Hardware & Operating SystemsJack Hyman
 
computer System UNit Every thing
computer System UNit Every thingcomputer System UNit Every thing
computer System UNit Every thingAbdul Rehman
 
Components of a digital computer.ppt
Components of a digital computer.pptComponents of a digital computer.ppt
Components of a digital computer.pptDibyenduBiswas31
 
BAIT1003 Chapter 2
BAIT1003 Chapter 2BAIT1003 Chapter 2
BAIT1003 Chapter 2limsh
 
06. System unit of computer
06. System unit of computer06. System unit of computer
06. System unit of computerTimesRide
 
COMPUTER BASIC AND FUNDAMENTAL AND ITS ORGANISATION.pptx
COMPUTER BASIC AND FUNDAMENTAL AND ITS ORGANISATION.pptxCOMPUTER BASIC AND FUNDAMENTAL AND ITS ORGANISATION.pptx
COMPUTER BASIC AND FUNDAMENTAL AND ITS ORGANISATION.pptxPannaBushratul
 

Ähnlich wie The system unit (20)

The system unit ch # 4
The system unit ch # 4The system unit ch # 4
The system unit ch # 4
 
Components of the System Unit.pdf
Components of the System Unit.pdfComponents of the System Unit.pdf
Components of the System Unit.pdf
 
3. Component of computer - System Unit ( CSI-321)
3. Component of computer - System Unit  ( CSI-321) 3. Component of computer - System Unit  ( CSI-321)
3. Component of computer - System Unit ( CSI-321)
 
System Unit
System UnitSystem Unit
System Unit
 
Computer - Hardware components
Computer -  Hardware componentsComputer -  Hardware components
Computer - Hardware components
 
Lecture 2 - Computer Hardware & Operating Systems
Lecture 2 - Computer Hardware & Operating SystemsLecture 2 - Computer Hardware & Operating Systems
Lecture 2 - Computer Hardware & Operating Systems
 
18. the components of the system unit
18. the components of the system unit18. the components of the system unit
18. the components of the system unit
 
Components of a computer
Components of a computerComponents of a computer
Components of a computer
 
computer System UNit Every thing
computer System UNit Every thingcomputer System UNit Every thing
computer System UNit Every thing
 
Components of a digital computer.ppt
Components of a digital computer.pptComponents of a digital computer.ppt
Components of a digital computer.ppt
 
Introduction to computer system
Introduction to computer systemIntroduction to computer system
Introduction to computer system
 
BAIT1003 Chapter 2
BAIT1003 Chapter 2BAIT1003 Chapter 2
BAIT1003 Chapter 2
 
Multimedia Technology
Multimedia TechnologyMultimedia Technology
Multimedia Technology
 
06. System unit of computer
06. System unit of computer06. System unit of computer
06. System unit of computer
 
COMPUTER BASIC AND FUNDAMENTAL AND ITS ORGANISATION.pptx
COMPUTER BASIC AND FUNDAMENTAL AND ITS ORGANISATION.pptxCOMPUTER BASIC AND FUNDAMENTAL AND ITS ORGANISATION.pptx
COMPUTER BASIC AND FUNDAMENTAL AND ITS ORGANISATION.pptx
 
system unit.ppt
system unit.pptsystem unit.ppt
system unit.ppt
 
Chapter 1 CSC118
Chapter 1 CSC118 Chapter 1 CSC118
Chapter 1 CSC118
 
Pankaj kumar
Pankaj kumar Pankaj kumar
Pankaj kumar
 
COMPUTER COMPONENTS
COMPUTER COMPONENTSCOMPUTER COMPONENTS
COMPUTER COMPONENTS
 
Computer Hardware
Computer HardwareComputer Hardware
Computer Hardware
 

Mehr von University Institute of Management sciences (12)

Business Ethic
Business EthicBusiness Ethic
Business Ethic
 
Business Ethic
Business EthicBusiness Ethic
Business Ethic
 
Business Ethic
Business EthicBusiness Ethic
Business Ethic
 
Receivable and inventory management
Receivable and inventory managementReceivable and inventory management
Receivable and inventory management
 
Overview of working capital management
Overview of working capital managementOverview of working capital management
Overview of working capital management
 
Fund analysis and cash flow analysis
Fund analysis and cash flow analysisFund analysis and cash flow analysis
Fund analysis and cash flow analysis
 
Estimation of cash flows
Estimation of cash flowsEstimation of cash flows
Estimation of cash flows
 
Cash and marketable securities
Cash and marketable securitiesCash and marketable securities
Cash and marketable securities
 
Analyzing the Marketing Environment
Analyzing the Marketing EnvironmentAnalyzing the Marketing Environment
Analyzing the Marketing Environment
 
Decision-Making: The Essence of the Manager’s Job
Decision-Making: The Essence of the Manager’s JobDecision-Making: The Essence of the Manager’s Job
Decision-Making: The Essence of the Manager’s Job
 
Chapter 1
Chapter 1Chapter 1
Chapter 1
 
Super computer
Super computerSuper computer
Super computer
 

The system unit

  • 1. The System Unit The system unit is a case that contains electronic components of the computer used to process data. System units are available in a variety of shapes and sizes.  The case of the system unit, sometimes called the chassis, is made of metal or plastic and protects the internal electronic components from damage.  All computers and mobile devices have a system Unit.
  • 3. The Motherboard  The motherboard, sometimes called a system board, is the main circuit board of the system unit.  Many electronic components attach to the Motherboard, others are built into it.
  • 4. Processor The processor, also called the central processing unit (CPU), interprets and carries out the basic instructions that operate a computer.  The processor significantly impacts overall computing power and manages most of a computer’s operations.  Most processor chip manufacturers now offer multi- core processors. A processor core, or simply core, contains the circuitry necessary to execute instructions.  Processors contain a control unit and an arithmetic logic unit (ALU).  These two components work together to perform processing operations.
  • 5. The Control Unit The control unit is the component of the processor that directs and coordinates most of the operations in the computer.  it interprets each instruction issued by a program and then initiates the appropriate action to carry out the instruction.  Types of internal components that the control unit directs include the arithmetic/logic unit , registers, and buses.
  • 6. The Arithmetic Logic Unit The arithmetic logic unit (ALU), another component of the processor, performs arithmetic, comparison, and Other operations.  Arithmetic operations include basic calculations such as addition, subtraction, multiplication, and division.  Comparison operations involve comparing one data item with another to determine whether the first item
  • 7. Machine Cycle For every instruction, a processor repeats a set of four basic operations, which comprise a machine cycle (1) fetching (2) Decoding (3) executing (4) storing
  • 8. • Fetching is the process of obtaining a program instruction or data item from memory. • Decoding refers to the process of translating the instruction into signals the computer can execute. • Executing is the process of carrying out the commands. • Storing, in this context, means writing the result to memory (not to a storage medium).
  • 10. Registers A processor contains small, high-speed storage locations, called registers, that temporarily hold data and instructions. Registers are part of the processor, not part of memory or a permanent storage device. Processors have many different types of registers, each with a specific storage function.
  • 11. The System Clock The processor relies on a small quartz crystal circuit called the system clock to control the timing of all computer operations. the system clock generates regular electronic pulses, or ticks, that set the operating pace of components of the system unit. Each tick equates to a clock cycle The pace of the system clock, called the clock speed, is measured by the number of ticks per second
  • 12. Processor Cooling  Heat sinks pipes and liquid cooling technologies often are used to help dissipate processor heat.  A heat sink is a small ceramic or metal component with fins on its surface that absorbs and disperses heat produced by electrical components such as a processor .
  • 14. Parallel Processing  Parallel processing is a method that uses multiple processors simultaneously to execute a single program or task .
  • 16. Memory • Memory consists of electronic components that store instructions waiting to be executed. • Memory stores three basic categories of items 1-: the operating system and other • system software that control or maintain the computer and its devices . 2-:application programs that carry out a specific task such as word processing . 3-:The data being processed by the application programs and resulting information.
  • 17. Memory Sizes  1 Kilobyte = 1,024  1 Megabyte =1,048,576  1 Gigabyte =1,073,741,824  1 Terabyte =1,099,511,627,776
  • 18. Types of Memory  volatile memory  Nonvolatile memory
  • 19. Types of Memory  RAM (random access memory), also called main memory, consists of memory chips that can be read from and written to by the processor and other devices.
  • 20. Types of Memory  TWO basic types of RAM 1-: Dynamic RAM 2-:Static RAM
  • 21. memory modules  There are three types of memory modules. 1-:SIMMs(single inline memory module) 2-:DIMMs(dual inline memory module) 3-:RIMMs(Rambus inlinememory module)
  • 23. Types of Memory  Cache Memory Cache Memory helps speed the processes of the computer because it stores frequently used instructions and data.
  • 24. types of memory cache  L1 cache  L2 cache
  • 25. types of memory cache • L1 cache L1 cache usually has a very small capacity ranging from 8 KB to 128 KB. The more common sizes for personal computers are 32 KB or 64 KB. • L2 cache L2 cache is slightly slower than L1 cache but has a much larger capacity, ranging from 64 KB to 16 MB.
  • 26. Types of Memory  ROM(Read only memory) ROM is nonvolatile, which means its contents are not lost when power is removed from the computer. In addition to computers, many devices contain ROM chips. For example, ROM chips in printers contain data for fonts.
  • 27. TYPES OF ROM  There are two types of ROM 1-:PROM 2-:EEPROM
  • 28. TYPES OF ROM • PROM (programmable read-only memory) A PROM chip is a blank ROM chip on which a programmer can write permanently. Programmers use microcode instructions to program a PROM chip. Once a programmer writes the microcode on the PROM chip, it functions like a regular ROM chip and cannot be erased or changed.
  • 29. TYPES OF ROM  EEPROM (electrically erasable programmable read-only memory) EEPROM chip, allows a programmer to erase the microcode with an electric signal.
  • 30. Types of Memory  Flash Memory Flash memory is a type of nonvolatile memory that can be erased electronically and rewritten, similar to EEPROM.
  • 31. Types of Memory • CMOS(complementary metal-oxide semiconductor)  (CMOS pronounced SEE-moss) technology because it provides high speeds and consumes little power.  CMOS technology uses battery power to retain information even when the power to the computer is off.  Battery-backed CMOS memory chips, for example, can keep the calendar, date, and time current even when the computer is off.  The flash memory chips that store a computer’s startup information often use CMOS technology.
  • 32. Memory Access Times  Access time is the amount of time it takes the processor to read data, instructions, and information from memory. A computer’s access time directly affects how fast the computer processes data.
  • 33. Expansion Slots and Adapter Cards • Expansion Slots An expansion slot is a socket on the motherboard that can hold an adapter card. • Adapter Cards An adapter card, sometimes called an expansion card, is a circuit board that enhances functions of a component of the system unit and/or provides connections to peripherals.
  • 35. Removable Flash Memory  A type of memory which can easily insert and remove from a slot of a personal computer.  A memory card is a removable flash memory device, usually no bigger than 1.5" in height or width, that you insert and remove from a slot in a personal computer, game console, mobile device, or card reader/writer.
  • 37. Ports and Connectors • PORTS A port is the point at which a peripheral attaches to or communicates with a system unit so that the peripheral can send data to or receive information from the computer. • CONNECTORS A connector joins a cable to a port. A connector at one end of a cable attaches to a port on the system unit, and a connector at the other end of the cable attaches to a port on the peripheral.
  • 39. Ports and Connectors • USB Ports A USB port, short for universal serial bus port, can connect up to 127 different peripherals together with a single connector. Devices that connect to a USB port include the following: mouse, printer, digital camera, scanner, speakers, portable media player, optical disc drive, smart phone, PDA, game console, and removable hard disk.
  • 40. Ports and Connectors  FireWire Ports FireWire port is similar to a USB port in that it can connect multiple types of devices that require faster data transmission speeds such as digital video cameras, digital VCRs, color printers, scanners, digital cameras, and DVD drives, to a single connector.
  • 41. Ports and Connectors  Bluetooth Port Bluetooth technology uses radio waves to transmit data between two devices. A Bluetooth wireless port adapter that will convert an existing USB port into a Bluetooth port .
  • 43. Ports and Connectors  SCSI Port A special high-speed parallel port called a SCSI port, allows you to attach SCSI(pronounced skuzzy) peripherals such as disk drives and printers.
  • 44. Ports and Connectors • eSATA Port • An eSATA port, or external SATA port, allows you to connect an external SATA (Serial Advanced Technology Attachment) hard disk to a computer. SATA hard disks are popular because of their fast data transmission speeds. • eSATA connections provide up to six times faster data transmission speeds than external hard disks attached to a computer’s USB or FireWire port .
  • 45. Ports and Connectors  IrDA Port  IrDA port is used infrared signals to transmit data one device to another device. Devices that use IrDA ports include a smart phone, PDA, keyboard, mouse, and printer. Several of these devices use a high-speed IrDA port, sometimes called a fast infrared port.
  • 47. Ports and Connectors • Serial Ports A serial port is a type of interface that connects a device to the system unit by transmitting data one bit at a time. • MIDI Port A special type of serial port that connects the system unit to a musical instrument , such as an electronic keyboard, is called a MIDI port.
  • 48. Port Replicators and Docking Stations  Port Replicators A port replicator is an external device that provides connections to peripherals through ports built into the device. The mobile user accesses peripherals by connecting the port replicator to a USB port or a special port on the mobile computer.
  • 49. Buses  Buses are used to transfer bits from input devices to memory, from memory to the processor, from the processor to memory, and from memory to output or storage devices.
  • 50. BUSES
  • 51. PARTS OF BUSES • There are two parts of buses • DATA BUS • ADDRESS BUS 1-:Data Bus The data bus is used to transfer actual data. 2-:Address Bus • The address bus is used to transfer information about where the data should reside in memory.
  • 52. TYPES OF BUSES • There three types of buses • System Bus • Backside Bus • Expansion Bus 1-:System Bus • A system bus, also called the front side bus ( FSB), is part of the motherboard and connects the processor to main memory.
  • 53. TYPES OF BUSES 2-:Backside Bus A backside bus ( BSB) connects the processor to cache. 3-:Expansion Bus An expansion bus allows the processor to communicate with peripherals.