SlideShare ist ein Scribd-Unternehmen logo
1 von 25
Downloaden Sie, um offline zu lesen
S.N.COLLEGE, GADHINGLAJ


Keyboard
S.N.COLLEGE, GADHINGLAJ

Keyboard




•   The
    keyboard is a peripheral device which is directly

    connected on to the motherboard (system board).

•   The keyboard is basically a set of switches (much like a
    typewriter)
•   Switches are connected in the form of a matrix, surrounded by
    electronic circuits
•   This Circuits monitor the key matrix that continuously scans the
    keys to recognize key action and generate a scan code.
S.N.COLLEGE, GADHINGLAJ

Key Boards Types
•   Serial keyboard
•   Parallel keyboard

•   Serial Keyboard
    –It is a keyboard which outputs the data in serial form, i.e. bit by bit.
    –The computer converts serial data into parallel 8-bit data.
    –They use only single line to transmit the data.
S.N.COLLEGE, GADHINGLAJ
    Parallel Keyboard

•   It is a keyboard which outputs all the 8-bits at a time in a
    parallel form.
•   All the bits are sent simultaneously on different lines.
•   In this the transmission is faster, needs a thicker cable with more number
    of wires.
•   In PCs we always use serial keyboards.
S.N.COLLEGE, GADHINGLAJ
Board Switches

•   Different types of key switches.
•   Mechanical key switches
•   Membrane key switches
•   Capacitive key switches
•   Hall effect key switches
•   Reed Relay key switches
S.N.COLLEGE, GADHINGLAJ

Functioning of the Keyboard
•   The processor in the original PC keyboard was an Intel 8048
    micro-controller chip
•   Newer keyboards often use an 8049 version that has own RAM,
    built in ROM or other micro-controller chips compatible with the
    8048 and 8049.
•   In an AT-type keyboard design, the keyboard serial interface is
    connected to a special keyboard controller on the
    motherboard(Intel 8042).
S.N.COLLEGE, GADHINGLAJ

Functioning of the Keyboard
•   When a switch is pressed, a processor in the keyboard itself
    identifies which key is pressed by identifying which grid
    location in the matrix shows continuity.
•   The keyboard processor also interprets how long the key is
    pressed and can even handle multiple keystrokes at the same
    time
S.N.COLLEGE, GADHINGLAJ

   Functioning of the Keyboard
• When you press a key, in most cases the contact actually bounces
  slightly .
• The processor in the keyboard is designed to filter this or
  debouncethe keystroke.
• The keyboard processor must distinguish bounce from a
  double key strike actually intended by the keyboard operator.
S.N.COLLEGE, GADHINGLAJ

   Functioning of the Keyboard
• Universal Peripheral Interface (UPI) slave micro controller chipis
  also available in the original AT design
• It has its own 2K of ROM and 128 bytes of RAM.
• Some systems may use the 8041 or 8741 chips, which differ only
    in the amount of built-in ROM or RAM
• Other systems now have the keyboard controller built into the main
  system chipset.
S.N.COLLEGE, GADHINGLAJ

Membrane switches
•   Very similar in operation to rubber dome keyboards.
•   A membrane keyboard does not have separate keys .
•   In this keyboard, two rubber or plastic sheet are used as row
    conductor sheet and column conductor sheet.
•   When the key top is pressed, it forces the row conductor sheet
    through the hole to touch the column conductor sheet.
S.N.COLLEGE, GADHINGLAJ

   Membrane switches
• These row and column lines are made on the plastic or single
  rubber sheet
• It uses silver or some other conductor ink for each row and column
  of keys with bulges for each key on the keyboard.
• This keyboard can be made very thin, as a completely sealed unit.
S.N.COLLEGE, GADHINGLAJ

   TypematicFunctions
• If a key on the keyboards is held down, it becomes typematic, which
  means that the keyboard repeatedly sends the key press
  code to the motherboard.
• In AT-style keyboards, typematic rate is adjustable by sending the
  keyboard processor the appropriate commands.
S.N.COLLEGE, GADHINGLAJ

Keyboard Interface
•   Interface between the keyboard cable and the system unit is the
    keyboard interface which is a DIN (or mini-DIN if it's a PS/2) plug
    that has five (or six, for mini-DIN) pins as shown.
•   All together there are four lines (wires) used for interfacing the
    keyboard with the system motherboard. They are
    – Keyboard data (KBDATA)
    – Keyboard clock (KBCLK)




    – DC source (+5V VCC)

    –DC ground (0V GND)
S.N.COLLEGE, GADHINGLAJ

   Keyboard Interface
• Universal Serial Bus (USB) interface is becoming more popular for
  keyboards, and some models may, in fact, require you to use a USB
  port unless you have a USB-to-PS/2 adapter to make the USB
  keyboard compatible with the PS/2 keyboard port.
• A USB connection is faster than the other, older I/O ports on your
  computer, such as COM and parallel ports.
S.N.COLLEGE, GADHINGLAJ

Common Keyboards Types
•   The most common keyboards are:
•   101-key Enhanced keyboard
•   104-key Windows keyboard
•   83-key PC and XT keyboard (Obsolete)
•   84-key AT keyboard (Obsolete)
S.N.COLLEGE, GADHINGLAJ

         Enhanced 101-Key (or 102-Key) Keyboard
   • In 1986, IBM introduced the "corporate" Enhanced 101-key
     keyboard for the newer XT and AT models.
   • IBM 101-key units originally came in versions with and without the
     status-indicator LEDs, depending on whether the unit was sold with
     an XT or AT system.
   • With the replacement of the Baby-AT motherboard and its five-pin
     DIN (an acronym for Deutsche Industries Norm) keyboard
     connector by ATX motherboards, which use the six-pin mini-DIN
     keyboard connector, virtually all keyboards on the market today
     come with cables for the six-pin mini-DIN connector introduced
      on the IBM PS/2s.
S.N.COLLEGE, GADHINGLAJ

Enhanced 101-Key (or 102-Key) Keyboard
•   101-key keyboard layout can be divided into the following four
    sections:
    –Typing area
    –Numeric keypad
    –Cursor and screen controls
    –Function keys
S.N.COLLEGE, GADHINGLAJ

104-Key (Windows 9x/Me/2000) Keyboard
•   When Microsoft released Windows 95, it also introduced the
    Microsoft Natural Keyboard, which implemented a revised
    keyboard specification that added three new Windows-specific
    keys to the keyboard.
•   104-key layout includes left and right Windows keys and an
    Application key which are used for operating system and
    application-level keyboard combinations, similar to the
    existing Ctrl and Alt combinations.
S.N.COLLEGE, GADHINGLAJ

104-Key (Windows 9x/Me/2000) Keyboard
•   Windows keyboard layout calls for the Left and Right Windows
    keys (called WIN keys) to flank the Alt keys on each side of the
    spacebar, as well as an Application key on the right of the Right
    Windows key.
•   WIN keys open the Windows Start menu, which you can then
    navigate with the cursor keys.
•   Application key simulates the right mouse button which in most
    applications, it brings up a context sensitive pop-up menu.
S.N.COLLEGE, GADHINGLAJ

Windows 9x/Me/2000 key combinations used
S.N.COLLEGE, GADHINGLAJ

   Cordless Keyboards
• These are like regular keyboards, except instead of having a
  keyboard cable that runs from the keyboard to the PC, they have no
  cord.
• Wired interface between the keyboard and the motherboard is
  replaced with a wireless one.




• They also typically cost more

      than the corded models.
S.N.COLLEGE, GADHINGLAJ

Multimedia and Web-Enabled Keyboards
•   Many keyboards feature fixed-purpose or programmable
    hotkeys that can launch Web browsers, run the Microsoft Media
    Player, adjust the volume on the speakers, change
    tracks on the CD player, and so forth.
•   Operating Systems such as Windows 98, Windows Me and
    Windows2000 support these keyboards to use their hot keys.
S.N.COLLEGE, GADHINGLAJ

Multimedia and Web-Enabled Keyboards
S.N.COLLEGE, GADHINGLAJ

Ergonomic Keyboards
•   A trend that began in the late 1990s is to change the shape of the
    keyboard instead of altering the character layout which has
    resulted in a number of so-called ergonomic designs.
•   Most common of these designs splits the keyboard in the centre,
    bending the sides outward.
Design & Published By:


S.N.Education Group,
Opp- Govt Rest House,
   Kadgaon Road,
    Gadhinglaj.

Weitere ähnliche Inhalte

Andere mochten auch

Christmas Guessing Game
Christmas Guessing GameChristmas Guessing Game
Christmas Guessing Gamejackonon
 
'ALT' CODES
'ALT' CODES'ALT' CODES
'ALT' CODESjackonon
 
29 Days Nutritional Information
29 Days Nutritional Information29 Days Nutritional Information
29 Days Nutritional Informationartsubsites
 
Pdhpe in primary school!
Pdhpe in primary school!Pdhpe in primary school!
Pdhpe in primary school!baxterto
 
Konkurs irlandia
Konkurs irlandiaKonkurs irlandia
Konkurs irlandiaAnna Wołk
 
Selena gomez
Selena gomezSelena gomez
Selena gomezJbastedo2
 
Tag Sell It Flea Market Directory
Tag Sell It Flea Market DirectoryTag Sell It Flea Market Directory
Tag Sell It Flea Market DirectoryTag Sell It Inc.
 
The Local-Vocal-Mobile Connection: Why Mobile is the new Local - Purna Virji-...
The Local-Vocal-Mobile Connection: Why Mobile is the new Local - Purna Virji-...The Local-Vocal-Mobile Connection: Why Mobile is the new Local - Purna Virji-...
The Local-Vocal-Mobile Connection: Why Mobile is the new Local - Purna Virji-...Purna Virji
 

Andere mochten auch (16)

Christmas Guessing Game
Christmas Guessing GameChristmas Guessing Game
Christmas Guessing Game
 
'ALT' CODES
'ALT' CODES'ALT' CODES
'ALT' CODES
 
29 Days Nutritional Information
29 Days Nutritional Information29 Days Nutritional Information
29 Days Nutritional Information
 
Pdhpe in primary school!
Pdhpe in primary school!Pdhpe in primary school!
Pdhpe in primary school!
 
My school 12
My school 12My school 12
My school 12
 
Welcome
WelcomeWelcome
Welcome
 
My school 10
My school 10My school 10
My school 10
 
Konkurs irlandia
Konkurs irlandiaKonkurs irlandia
Konkurs irlandia
 
第二次
第二次第二次
第二次
 
Crislitbillar
CrislitbillarCrislitbillar
Crislitbillar
 
My school 3
My school 3My school 3
My school 3
 
Selena gomez
Selena gomezSelena gomez
Selena gomez
 
Tag Sell It Flea Market Directory
Tag Sell It Flea Market DirectoryTag Sell It Flea Market Directory
Tag Sell It Flea Market Directory
 
Live Auction
Live AuctionLive Auction
Live Auction
 
Obradoiro de debuxo
Obradoiro de debuxoObradoiro de debuxo
Obradoiro de debuxo
 
The Local-Vocal-Mobile Connection: Why Mobile is the new Local - Purna Virji-...
The Local-Vocal-Mobile Connection: Why Mobile is the new Local - Purna Virji-...The Local-Vocal-Mobile Connection: Why Mobile is the new Local - Purna Virji-...
The Local-Vocal-Mobile Connection: Why Mobile is the new Local - Purna Virji-...
 

Ähnlich wie Keybord

AN OVERVIEW ON KEYBOARD AND MOUSE
AN OVERVIEW ON KEYBOARD AND MOUSEAN OVERVIEW ON KEYBOARD AND MOUSE
AN OVERVIEW ON KEYBOARD AND MOUSEMithun Ghose
 
การสอนคอมพิวเตอร์
การสอนคอมพิวเตอร์การสอนคอมพิวเตอร์
การสอนคอมพิวเตอร์perachaue
 
การสอนคอมพิวเตอร์
การสอนคอมพิวเตอร์การสอนคอมพิวเตอร์
การสอนคอมพิวเตอร์perachaue
 
Computer system
Computer systemComputer system
Computer systemzamzulaiha
 
Basic computerparts
Basic computerpartsBasic computerparts
Basic computerpartssaidfuad91
 
Study of Peripherals of computer System.pdf
Study of Peripherals of computer System.pdfStudy of Peripherals of computer System.pdf
Study of Peripherals of computer System.pdfRAJARATNAS
 
Interacting with your computer
Interacting with your computerInteracting with your computer
Interacting with your computerWaqas Ahmed
 
5 parts of a computer
5 parts of a computer5 parts of a computer
5 parts of a computerdaniel
 
HARDWARE AND PC MAINTENANCE -THE COMPLETE PC-MRS SOWMYA JYOTHI REFERENCE-MIKE...
HARDWARE AND PC MAINTENANCE -THE COMPLETE PC-MRS SOWMYA JYOTHI REFERENCE-MIKE...HARDWARE AND PC MAINTENANCE -THE COMPLETE PC-MRS SOWMYA JYOTHI REFERENCE-MIKE...
HARDWARE AND PC MAINTENANCE -THE COMPLETE PC-MRS SOWMYA JYOTHI REFERENCE-MIKE...Sowmya Jyothi
 
Lecture 1 Introduction.pptx
Lecture 1 Introduction.pptxLecture 1 Introduction.pptx
Lecture 1 Introduction.pptxOrchestra2
 
Recent advances in peripheral devices
Recent advances in peripheral devicesRecent advances in peripheral devices
Recent advances in peripheral devicesShakshi Ranawat
 

Ähnlich wie Keybord (20)

AN OVERVIEW ON KEYBOARD AND MOUSE
AN OVERVIEW ON KEYBOARD AND MOUSEAN OVERVIEW ON KEYBOARD AND MOUSE
AN OVERVIEW ON KEYBOARD AND MOUSE
 
MIT81 Presentation 1.pptx
MIT81 Presentation 1.pptxMIT81 Presentation 1.pptx
MIT81 Presentation 1.pptx
 
MIT81 Presentation 1.pptx
MIT81 Presentation 1.pptxMIT81 Presentation 1.pptx
MIT81 Presentation 1.pptx
 
การสอนคอมพิวเตอร์
การสอนคอมพิวเตอร์การสอนคอมพิวเตอร์
การสอนคอมพิวเตอร์
 
computer
computercomputer
computer
 
การสอนคอมพิวเตอร์
การสอนคอมพิวเตอร์การสอนคอมพิวเตอร์
การสอนคอมพิวเตอร์
 
Computer Parts
Computer PartsComputer Parts
Computer Parts
 
Pc components
Pc componentsPc components
Pc components
 
Computer system
Computer systemComputer system
Computer system
 
Basic computerparts
Basic computerpartsBasic computerparts
Basic computerparts
 
Lecture 3: The Visible PC
Lecture 3: The Visible PCLecture 3: The Visible PC
Lecture 3: The Visible PC
 
Keyboard
KeyboardKeyboard
Keyboard
 
Basics of computer
Basics of computerBasics of computer
Basics of computer
 
Study of Peripherals of computer System.pdf
Study of Peripherals of computer System.pdfStudy of Peripherals of computer System.pdf
Study of Peripherals of computer System.pdf
 
Interacting with your computer
Interacting with your computerInteracting with your computer
Interacting with your computer
 
5 parts of a computer
5 parts of a computer5 parts of a computer
5 parts of a computer
 
HARDWARE AND PC MAINTENANCE -THE COMPLETE PC-MRS SOWMYA JYOTHI REFERENCE-MIKE...
HARDWARE AND PC MAINTENANCE -THE COMPLETE PC-MRS SOWMYA JYOTHI REFERENCE-MIKE...HARDWARE AND PC MAINTENANCE -THE COMPLETE PC-MRS SOWMYA JYOTHI REFERENCE-MIKE...
HARDWARE AND PC MAINTENANCE -THE COMPLETE PC-MRS SOWMYA JYOTHI REFERENCE-MIKE...
 
Lecture 1 Introduction.pptx
Lecture 1 Introduction.pptxLecture 1 Introduction.pptx
Lecture 1 Introduction.pptx
 
Recent advances in peripheral devices
Recent advances in peripheral devicesRecent advances in peripheral devices
Recent advances in peripheral devices
 
Desktop Assembing.pptx
Desktop Assembing.pptxDesktop Assembing.pptx
Desktop Assembing.pptx
 

Mehr von Ravi Kodoli

Gadhinglaj Map.pdf
Gadhinglaj Map.pdfGadhinglaj Map.pdf
Gadhinglaj Map.pdfRavi Kodoli
 
Virtual local area networks
Virtual local area networksVirtual local area networks
Virtual local area networksRavi Kodoli
 
Full form of hardware and networking devices and terminology
Full form of hardware and networking devices and terminologyFull form of hardware and networking devices and terminology
Full form of hardware and networking devices and terminologyRavi Kodoli
 
All in one q & ans
All in one q & ansAll in one q & ans
All in one q & ansRavi Kodoli
 

Mehr von Ravi Kodoli (8)

Gadhinglaj Map.pdf
Gadhinglaj Map.pdfGadhinglaj Map.pdf
Gadhinglaj Map.pdf
 
Virtual local area networks
Virtual local area networksVirtual local area networks
Virtual local area networks
 
H n q & a
H n q & aH n q & a
H n q & a
 
Full form of hardware and networking devices and terminology
Full form of hardware and networking devices and terminologyFull form of hardware and networking devices and terminology
Full form of hardware and networking devices and terminology
 
All in one q & ans
All in one q & ansAll in one q & ans
All in one q & ans
 
Printer
PrinterPrinter
Printer
 
Moues
MouesMoues
Moues
 
Memory
MemoryMemory
Memory
 

Kürzlich hochgeladen

What is the Future of QuickBooks DeskTop?
What is the Future of QuickBooks DeskTop?What is the Future of QuickBooks DeskTop?
What is the Future of QuickBooks DeskTop?TechSoup
 
Prescribed medication order and communication skills.pptx
Prescribed medication order and communication skills.pptxPrescribed medication order and communication skills.pptx
Prescribed medication order and communication skills.pptxraviapr7
 
Human-AI Co-Creation of Worked Examples for Programming Classes
Human-AI Co-Creation of Worked Examples for Programming ClassesHuman-AI Co-Creation of Worked Examples for Programming Classes
Human-AI Co-Creation of Worked Examples for Programming ClassesMohammad Hassany
 
How to Add a New Field in Existing Kanban View in Odoo 17
How to Add a New Field in Existing Kanban View in Odoo 17How to Add a New Field in Existing Kanban View in Odoo 17
How to Add a New Field in Existing Kanban View in Odoo 17Celine George
 
Clinical Pharmacy Introduction to Clinical Pharmacy, Concept of clinical pptx
Clinical Pharmacy  Introduction to Clinical Pharmacy, Concept of clinical pptxClinical Pharmacy  Introduction to Clinical Pharmacy, Concept of clinical pptx
Clinical Pharmacy Introduction to Clinical Pharmacy, Concept of clinical pptxraviapr7
 
HED Office Sohayok Exam Question Solution 2023.pdf
HED Office Sohayok Exam Question Solution 2023.pdfHED Office Sohayok Exam Question Solution 2023.pdf
HED Office Sohayok Exam Question Solution 2023.pdfMohonDas
 
Presentation on the Basics of Writing. Writing a Paragraph
Presentation on the Basics of Writing. Writing a ParagraphPresentation on the Basics of Writing. Writing a Paragraph
Presentation on the Basics of Writing. Writing a ParagraphNetziValdelomar1
 
UKCGE Parental Leave Discussion March 2024
UKCGE Parental Leave Discussion March 2024UKCGE Parental Leave Discussion March 2024
UKCGE Parental Leave Discussion March 2024UKCGE
 
M-2- General Reactions of amino acids.pptx
M-2- General Reactions of amino acids.pptxM-2- General Reactions of amino acids.pptx
M-2- General Reactions of amino acids.pptxDr. Santhosh Kumar. N
 
Quality Assurance_GOOD LABORATORY PRACTICE
Quality Assurance_GOOD LABORATORY PRACTICEQuality Assurance_GOOD LABORATORY PRACTICE
Quality Assurance_GOOD LABORATORY PRACTICESayali Powar
 
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdfMaximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdfTechSoup
 
Drug Information Services- DIC and Sources.
Drug Information Services- DIC and Sources.Drug Information Services- DIC and Sources.
Drug Information Services- DIC and Sources.raviapr7
 
CapTechU Doctoral Presentation -March 2024 slides.pptx
CapTechU Doctoral Presentation -March 2024 slides.pptxCapTechU Doctoral Presentation -March 2024 slides.pptx
CapTechU Doctoral Presentation -March 2024 slides.pptxCapitolTechU
 
Patient Counselling. Definition of patient counseling; steps involved in pati...
Patient Counselling. Definition of patient counseling; steps involved in pati...Patient Counselling. Definition of patient counseling; steps involved in pati...
Patient Counselling. Definition of patient counseling; steps involved in pati...raviapr7
 
The basics of sentences session 10pptx.pptx
The basics of sentences session 10pptx.pptxThe basics of sentences session 10pptx.pptx
The basics of sentences session 10pptx.pptxheathfieldcps1
 
P4C x ELT = P4ELT: Its Theoretical Background (Kanazawa, 2024 March).pdf
P4C x ELT = P4ELT: Its Theoretical Background (Kanazawa, 2024 March).pdfP4C x ELT = P4ELT: Its Theoretical Background (Kanazawa, 2024 March).pdf
P4C x ELT = P4ELT: Its Theoretical Background (Kanazawa, 2024 March).pdfYu Kanazawa / Osaka University
 
Diploma in Nursing Admission Test Question Solution 2023.pdf
Diploma in Nursing Admission Test Question Solution 2023.pdfDiploma in Nursing Admission Test Question Solution 2023.pdf
Diploma in Nursing Admission Test Question Solution 2023.pdfMohonDas
 
How to Use api.constrains ( ) in Odoo 17
How to Use api.constrains ( ) in Odoo 17How to Use api.constrains ( ) in Odoo 17
How to Use api.constrains ( ) in Odoo 17Celine George
 

Kürzlich hochgeladen (20)

What is the Future of QuickBooks DeskTop?
What is the Future of QuickBooks DeskTop?What is the Future of QuickBooks DeskTop?
What is the Future of QuickBooks DeskTop?
 
Prescribed medication order and communication skills.pptx
Prescribed medication order and communication skills.pptxPrescribed medication order and communication skills.pptx
Prescribed medication order and communication skills.pptx
 
Human-AI Co-Creation of Worked Examples for Programming Classes
Human-AI Co-Creation of Worked Examples for Programming ClassesHuman-AI Co-Creation of Worked Examples for Programming Classes
Human-AI Co-Creation of Worked Examples for Programming Classes
 
How to Add a New Field in Existing Kanban View in Odoo 17
How to Add a New Field in Existing Kanban View in Odoo 17How to Add a New Field in Existing Kanban View in Odoo 17
How to Add a New Field in Existing Kanban View in Odoo 17
 
Clinical Pharmacy Introduction to Clinical Pharmacy, Concept of clinical pptx
Clinical Pharmacy  Introduction to Clinical Pharmacy, Concept of clinical pptxClinical Pharmacy  Introduction to Clinical Pharmacy, Concept of clinical pptx
Clinical Pharmacy Introduction to Clinical Pharmacy, Concept of clinical pptx
 
HED Office Sohayok Exam Question Solution 2023.pdf
HED Office Sohayok Exam Question Solution 2023.pdfHED Office Sohayok Exam Question Solution 2023.pdf
HED Office Sohayok Exam Question Solution 2023.pdf
 
Presentation on the Basics of Writing. Writing a Paragraph
Presentation on the Basics of Writing. Writing a ParagraphPresentation on the Basics of Writing. Writing a Paragraph
Presentation on the Basics of Writing. Writing a Paragraph
 
UKCGE Parental Leave Discussion March 2024
UKCGE Parental Leave Discussion March 2024UKCGE Parental Leave Discussion March 2024
UKCGE Parental Leave Discussion March 2024
 
M-2- General Reactions of amino acids.pptx
M-2- General Reactions of amino acids.pptxM-2- General Reactions of amino acids.pptx
M-2- General Reactions of amino acids.pptx
 
Quality Assurance_GOOD LABORATORY PRACTICE
Quality Assurance_GOOD LABORATORY PRACTICEQuality Assurance_GOOD LABORATORY PRACTICE
Quality Assurance_GOOD LABORATORY PRACTICE
 
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdfMaximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
 
Drug Information Services- DIC and Sources.
Drug Information Services- DIC and Sources.Drug Information Services- DIC and Sources.
Drug Information Services- DIC and Sources.
 
CapTechU Doctoral Presentation -March 2024 slides.pptx
CapTechU Doctoral Presentation -March 2024 slides.pptxCapTechU Doctoral Presentation -March 2024 slides.pptx
CapTechU Doctoral Presentation -March 2024 slides.pptx
 
Patient Counselling. Definition of patient counseling; steps involved in pati...
Patient Counselling. Definition of patient counseling; steps involved in pati...Patient Counselling. Definition of patient counseling; steps involved in pati...
Patient Counselling. Definition of patient counseling; steps involved in pati...
 
The basics of sentences session 10pptx.pptx
The basics of sentences session 10pptx.pptxThe basics of sentences session 10pptx.pptx
The basics of sentences session 10pptx.pptx
 
P4C x ELT = P4ELT: Its Theoretical Background (Kanazawa, 2024 March).pdf
P4C x ELT = P4ELT: Its Theoretical Background (Kanazawa, 2024 March).pdfP4C x ELT = P4ELT: Its Theoretical Background (Kanazawa, 2024 March).pdf
P4C x ELT = P4ELT: Its Theoretical Background (Kanazawa, 2024 March).pdf
 
Diploma in Nursing Admission Test Question Solution 2023.pdf
Diploma in Nursing Admission Test Question Solution 2023.pdfDiploma in Nursing Admission Test Question Solution 2023.pdf
Diploma in Nursing Admission Test Question Solution 2023.pdf
 
How to Use api.constrains ( ) in Odoo 17
How to Use api.constrains ( ) in Odoo 17How to Use api.constrains ( ) in Odoo 17
How to Use api.constrains ( ) in Odoo 17
 
Personal Resilience in Project Management 2 - TV Edit 1a.pdf
Personal Resilience in Project Management 2 - TV Edit 1a.pdfPersonal Resilience in Project Management 2 - TV Edit 1a.pdf
Personal Resilience in Project Management 2 - TV Edit 1a.pdf
 
Prelims of Kant get Marx 2.0: a general politics quiz
Prelims of Kant get Marx 2.0: a general politics quizPrelims of Kant get Marx 2.0: a general politics quiz
Prelims of Kant get Marx 2.0: a general politics quiz
 

Keybord

  • 2. S.N.COLLEGE, GADHINGLAJ Keyboard • The keyboard is a peripheral device which is directly connected on to the motherboard (system board). • The keyboard is basically a set of switches (much like a typewriter) • Switches are connected in the form of a matrix, surrounded by electronic circuits • This Circuits monitor the key matrix that continuously scans the keys to recognize key action and generate a scan code.
  • 3. S.N.COLLEGE, GADHINGLAJ Key Boards Types • Serial keyboard • Parallel keyboard • Serial Keyboard –It is a keyboard which outputs the data in serial form, i.e. bit by bit. –The computer converts serial data into parallel 8-bit data. –They use only single line to transmit the data.
  • 4. S.N.COLLEGE, GADHINGLAJ Parallel Keyboard • It is a keyboard which outputs all the 8-bits at a time in a parallel form. • All the bits are sent simultaneously on different lines. • In this the transmission is faster, needs a thicker cable with more number of wires. • In PCs we always use serial keyboards.
  • 5. S.N.COLLEGE, GADHINGLAJ Board Switches • Different types of key switches. • Mechanical key switches • Membrane key switches • Capacitive key switches • Hall effect key switches • Reed Relay key switches
  • 6. S.N.COLLEGE, GADHINGLAJ Functioning of the Keyboard • The processor in the original PC keyboard was an Intel 8048 micro-controller chip • Newer keyboards often use an 8049 version that has own RAM, built in ROM or other micro-controller chips compatible with the 8048 and 8049. • In an AT-type keyboard design, the keyboard serial interface is connected to a special keyboard controller on the motherboard(Intel 8042).
  • 7. S.N.COLLEGE, GADHINGLAJ Functioning of the Keyboard • When a switch is pressed, a processor in the keyboard itself identifies which key is pressed by identifying which grid location in the matrix shows continuity. • The keyboard processor also interprets how long the key is pressed and can even handle multiple keystrokes at the same time
  • 8. S.N.COLLEGE, GADHINGLAJ Functioning of the Keyboard • When you press a key, in most cases the contact actually bounces slightly . • The processor in the keyboard is designed to filter this or debouncethe keystroke. • The keyboard processor must distinguish bounce from a double key strike actually intended by the keyboard operator.
  • 9. S.N.COLLEGE, GADHINGLAJ Functioning of the Keyboard • Universal Peripheral Interface (UPI) slave micro controller chipis also available in the original AT design • It has its own 2K of ROM and 128 bytes of RAM. • Some systems may use the 8041 or 8741 chips, which differ only in the amount of built-in ROM or RAM • Other systems now have the keyboard controller built into the main system chipset.
  • 10. S.N.COLLEGE, GADHINGLAJ Membrane switches • Very similar in operation to rubber dome keyboards. • A membrane keyboard does not have separate keys . • In this keyboard, two rubber or plastic sheet are used as row conductor sheet and column conductor sheet. • When the key top is pressed, it forces the row conductor sheet through the hole to touch the column conductor sheet.
  • 11. S.N.COLLEGE, GADHINGLAJ Membrane switches • These row and column lines are made on the plastic or single rubber sheet • It uses silver or some other conductor ink for each row and column of keys with bulges for each key on the keyboard. • This keyboard can be made very thin, as a completely sealed unit.
  • 12. S.N.COLLEGE, GADHINGLAJ TypematicFunctions • If a key on the keyboards is held down, it becomes typematic, which means that the keyboard repeatedly sends the key press code to the motherboard. • In AT-style keyboards, typematic rate is adjustable by sending the keyboard processor the appropriate commands.
  • 13. S.N.COLLEGE, GADHINGLAJ Keyboard Interface • Interface between the keyboard cable and the system unit is the keyboard interface which is a DIN (or mini-DIN if it's a PS/2) plug that has five (or six, for mini-DIN) pins as shown. • All together there are four lines (wires) used for interfacing the keyboard with the system motherboard. They are – Keyboard data (KBDATA) – Keyboard clock (KBCLK) – DC source (+5V VCC) –DC ground (0V GND)
  • 14. S.N.COLLEGE, GADHINGLAJ Keyboard Interface • Universal Serial Bus (USB) interface is becoming more popular for keyboards, and some models may, in fact, require you to use a USB port unless you have a USB-to-PS/2 adapter to make the USB keyboard compatible with the PS/2 keyboard port. • A USB connection is faster than the other, older I/O ports on your computer, such as COM and parallel ports.
  • 15. S.N.COLLEGE, GADHINGLAJ Common Keyboards Types • The most common keyboards are: • 101-key Enhanced keyboard • 104-key Windows keyboard • 83-key PC and XT keyboard (Obsolete) • 84-key AT keyboard (Obsolete)
  • 16. S.N.COLLEGE, GADHINGLAJ Enhanced 101-Key (or 102-Key) Keyboard • In 1986, IBM introduced the "corporate" Enhanced 101-key keyboard for the newer XT and AT models. • IBM 101-key units originally came in versions with and without the status-indicator LEDs, depending on whether the unit was sold with an XT or AT system. • With the replacement of the Baby-AT motherboard and its five-pin DIN (an acronym for Deutsche Industries Norm) keyboard connector by ATX motherboards, which use the six-pin mini-DIN keyboard connector, virtually all keyboards on the market today come with cables for the six-pin mini-DIN connector introduced on the IBM PS/2s.
  • 17. S.N.COLLEGE, GADHINGLAJ Enhanced 101-Key (or 102-Key) Keyboard • 101-key keyboard layout can be divided into the following four sections: –Typing area –Numeric keypad –Cursor and screen controls –Function keys
  • 18. S.N.COLLEGE, GADHINGLAJ 104-Key (Windows 9x/Me/2000) Keyboard • When Microsoft released Windows 95, it also introduced the Microsoft Natural Keyboard, which implemented a revised keyboard specification that added three new Windows-specific keys to the keyboard. • 104-key layout includes left and right Windows keys and an Application key which are used for operating system and application-level keyboard combinations, similar to the existing Ctrl and Alt combinations.
  • 19. S.N.COLLEGE, GADHINGLAJ 104-Key (Windows 9x/Me/2000) Keyboard • Windows keyboard layout calls for the Left and Right Windows keys (called WIN keys) to flank the Alt keys on each side of the spacebar, as well as an Application key on the right of the Right Windows key. • WIN keys open the Windows Start menu, which you can then navigate with the cursor keys. • Application key simulates the right mouse button which in most applications, it brings up a context sensitive pop-up menu.
  • 21. S.N.COLLEGE, GADHINGLAJ Cordless Keyboards • These are like regular keyboards, except instead of having a keyboard cable that runs from the keyboard to the PC, they have no cord. • Wired interface between the keyboard and the motherboard is replaced with a wireless one. • They also typically cost more than the corded models.
  • 22. S.N.COLLEGE, GADHINGLAJ Multimedia and Web-Enabled Keyboards • Many keyboards feature fixed-purpose or programmable hotkeys that can launch Web browsers, run the Microsoft Media Player, adjust the volume on the speakers, change tracks on the CD player, and so forth. • Operating Systems such as Windows 98, Windows Me and Windows2000 support these keyboards to use their hot keys.
  • 23. S.N.COLLEGE, GADHINGLAJ Multimedia and Web-Enabled Keyboards
  • 24. S.N.COLLEGE, GADHINGLAJ Ergonomic Keyboards • A trend that began in the late 1990s is to change the shape of the keyboard instead of altering the character layout which has resulted in a number of so-called ergonomic designs. • Most common of these designs splits the keyboard in the centre, bending the sides outward.
  • 25. Design & Published By: S.N.Education Group, Opp- Govt Rest House, Kadgaon Road, Gadhinglaj.