What is Computer Hardware ?
A computing device or computer can usually be divided into two parts. These are external hardware and emotional instruction software. Computer hardware or computer hardware is those parts of the computer that can be touched and seen, such as: – monitor, mouse, casing, motherboard, ROM, CD, DVD, etc.
Computer Components A personal computer is made up of different types of components. It then installs operating system (system software) and installs various practical instructions or application software as per user requirements.
What are the types of computer hardware?
Computer hardware is generally of three types:-
- Output Device
- Input Device
- Both Device
Output Devices :-
- LCD Projection Panels
- Monitor (LED, LCD, CRT etc)
- Printers (all types)
- Head Phone
- Computer Output Microfilm (COM)
- Film Recorder
- Graphics Tablets
- Video Capture Hardware
- Barcode reader
- Digital camera
- Electronic Whiteboard
- Pen Input
- Punch card reader
Both Input-Output Devices :-
- Touch Screen
- Network cards
- Audio Cards / Sound Card
- Headsets (Headset consists of Speakers and Microphone.
- Facsimile (FAX) (It has scanner to scan the document and also have printer to Print the document)
A monitor or display is an electronic visual aid display for a computer. A monitor typically consists of a display device, circuitry, casing, and power supply. Mostly used as the main output device of the computer.
A monitor generally refers to a large device such as a television, but in technology the concept of monitor is also used in a broader sense. A monitor is a tool that directly monitors the processes running on the system.
General Instructing Devices:-
- Optical mouse
- Wireless mouse
- Mechanical mouse
3. Touch screen
4. Light pen
A mouse is a piece of hardware used to operate a computer. In the late 1960s, Doug Engelbart of the Stanford Research Institute first discovered the mouse. But in the 1970s it gained popularity not only in Xerox computers. In the 1980s, Apple Computer first introduced it in their Macintosh series, its shape resembles a mouse hence the name mouse.
It is an input device, through which control can be established anywhere on the monitor or in the program. Thanks to this, operating systems with graphics user interfaces or GUIs are expanding so rapidly.
Optical Mouse –
An optical mouse is a computer mouse that uses a light source and light detection system to sense movement or change of direction on an object’s surface and displays cursor movements on the computer display accordingly.
It usually uses LED or LED as light source and photodiode is used for light detection. It is used as an alternative to mechanical mouse or trackball mouse. A mechanical mouse uses a rotating device, usually a ball, to determine the direction and location of movement.
The earliest optical mice could capture movement on pre-printed mousepads. Today’s modern optical mice mostly operate on opaque or hard (reflectively diffuse) surfaces.
In general, optical mice perform poorly on objects whose surface receives light from a single source and is reflected back to the same angle.
A mouse with a coherently-lit (laser) feature works well on objects with glossy surfaces but does not work well on bright surfaces. Mice that have dark field illumination also work well on glass.
Laser diodes are used for light detection for precise movement and positioning. In wireless and battery-powered optical mice, the LEDs light up when the mouse detects movement to save battery power.
Touch sensitive screen :-
How does touch screen-
A touch screen is both an information input and output device and is usually the upper layer of an electronic display screen in an information processing system. A user can enter data or control data processing methods through simple one-touch or multi-touch gestures by touching the screen with a specialized stylus or one or more fingers.
Some sensors use ordinary or specially coated gloves to work, and others can only work using special styluses or pens. The user can use the touch screen to respond to what is displayed and if the software allows control of how it is displayed; For example, increasing the size of a text by zooming.
A touchscreen enables direct interaction with the display rather than using a mouse, touchpad, or other devices (except for a stylus, which is optional for most modern touchscreens).
Touchscreens are found in devices such as game consoles, personal computers, electronic voting machines, and point-of-sale (POS) systems. They can be connected to computers or networks as endpoints (terminals).
They play a special role in the design of digital devices such as personal digital assistants (Personal Digital Assistants or PDAs) and some electronic reading devices. Touchscreens are also important for educational environments such as classrooms or higher education institutions.
Use of varius work touchscreen –
The popularity of smartphones, tablets and many other types of information devices is increasing the adoption of touchscreens for portable and functional electronics.
Touchscreens are found in the medical field, heavy industry, automated teller machines (ATMs) and kiosks as museum displays or room automation, where keyboard and mouse systems are customized by the user.
History of touchscreen –
Historically, touchscreen sensors and their accompanying controller-based firmware have been made available by a wide array of after-market system integrators, but not by display, chip, or motherboard manufacturers.
Display manufacturers and chip manufacturers have recognized the acceptance of touch screens as user interface components and are using touch screens as the basic design of their products.
Light Pen :-
What is light pen?
A light pen is a computer input device that looks like a long, thin stick. It has photosensitive properties that are used in conjunction with computer CRT displays. It allows the user to point or draw objects on the display as is done on a touchscreen but with precision.
It works with other display technologies, including CRT displays, but the concept of using a light pen with LCD monitors is not clear (although Toshiba and Hitachi demonstrated such concepts at “Display 2006” in Japan).
How does work light pen?
A light pen captures changes in brightness of pixels on the display, as the electron beam scans the CRT display and transmits these changes to the computer. Because the CRT display scans one pixel of the entire display at a single time, the computer can track the specific scanning time of the light pen and track changes in beam position and light pen position. Counting time
What is keyboard?
A keyboard is a typewriter-inspired device with an arrangement of buttons that act like mechanical levers or electronic switches. The keyboard is the main input device of the computer. Keys are printed on keyboard keys.
Press or hold down one or more keys to create a symbol. After the invention of mouse, touchscreen, pen, voice recognition, keyboard is the most widely used and versatile input device.
There are different types of keyboards-
1. By design
- Laptop size
- Thumb sized
- Environment friendly
- Foldable keyboard
2. Based on the connection
- Wireless frequency
3. Special keyboard
- Multimedia and Games
- Asad (Virtual)
Keyboard Introduction :-
The keyboard has 84 to 101 keys or some keyboards have 102 keys. Keyboards can be roughly divided into 5 categories based on usage:-
- function key
- Arrow key
- Alphabetical key
- Numeric key or logical key
- special key
The keys F1 to F12 on the upper left side of the keyboard are collectively called function keys. The reason why they are called function keys (together) is that certain things can be done through them. For example, these keys are used to help a program or to run a program.
Arrow Keys :-
There are four individual keys on the lower right side of the keyboard. Some keys are also on top of the board. The keys are marked with arrows. With which you can easily move the cursor right, left, up and down. These are also called edit keys. Because these keys are also used for text editing.
The part of the key board where the English alphabet is arranged from A to Z is called the alphabetical section.
Numeric Key or Logical Key:-
The keys with numbers 0 to 9 on the right side of the keyboard are called numeric keys. There are arithmetic operators like +, -, *, / etc. Also the logical operators <, >, = are on the key board.
Special Key :-
Apart from the mentioned keys, the other keys on the keyboard perform some special function, so they are called special keys-
Esc: Use this key to cancel any command.
Tab: This key is used to adjust the paragraph, column, number, paragraph start space etc. on the screen as required.
Caps Lock: Use this key to type English lowercase and uppercase letters.
Shift: This key is used to type upper and lower case letters within or at the beginning of the same word. Eg: To write two words Dhaka, Khulna press the shift key on the first letter and release the shift key for the next letters.
And in writing Bengali Or or alphabets, this key is used for writing type above and below the letter layout key. Besides, various commands are given to the computer by pressing function keys along with shift key.
Ctrl: Commands are given by pressing this key together with the special key. There are 2 keys on the right and left side of the keyboard for user convenience.
Alt: This key is used differently in different programs to give different commands and create different commands.
Enter: This key is used to execute an instruction to the computer. This key is also used to create new paragraphs for writing.
Pause Break: If any text on the computer is difficult to read for fast speed, then this key can be read.
Print Screen: Use this key to print everything visible on the computer screen.
Delete: This key is used to delete a sentence, letter or text
Home: This key brings the cursor to the top of the page. However, while writing a document in MS Word, to bring the cursor to the first page, press Ctrl+Home together.
End: Pressing this key will move the cursor or pointer to the end of the text or page wherever it is.
Page Up: Use this key to move the cursor upwards.
Page Down: Use this key to move the cursor down.
Insert: If something is entered between a text, it is usually written to the right of the text, but pressing this key overwrites the previous letter. Pressing this key again at the end of the work returns to the previous state.
Back Space: This key is used to delete the back space of a text.
Space Bar: This key is the longest among the keys on the keyboard and is used to space between words while writing a long sentence.
Num Look: When this key is pressed, the keys on the right turn on
Multimedia Keys :-
Apart from this, the multimedia keyboard has 4 more keys:-
Stand by Mood: Holding down this key will keep the computer on but the monitor off.
Mail key: Press this key to launch Outlook Express and use it to send mail. But the internet must be on.
Web key: This key can be used to open the web browser directly. and can browse the internet.
Start Menu key: Press this key to open the start menu and perform necessary commands.
- game pad
- game controller
A joystick is an input device consisting of a stick or stick-like object mounted on the surface of the device that can be used to manipulate the device controlled by it in various directions.
Joystick also called control column is used in almost all military and civil aircraft cockpits. They are used as side sticks or central sticks. They also have some additional switches that help in flight control.
Joysticks are often used to control video games and usually consist of one or more buttons that can be pressed. The computer understands the result of pressing all these buttons.
Another popular variant of this joystick is the analog stick used in modern video game consoles. Joysticks are used in many devices such as cranes, trucks, unmanned underwater vehicles, wheelchairs, security cameras, and lawn mowers. The smallest version of the joystick is seen on mobile phones.
Photography and film mechanics –
- Digital camera
- Fingerprint scanner
- Barcode reader
- 3D scanner
- Laser rangefinder
Digital Camera :-
Digital cameras refer to cameras that do not use traditional film, but instead store images in a memory chip.
Digital camera quality is measured in mega pixels: the more mega pixels, the larger the image capture capacity. Although initially expensive, film cameras are quickly coming down in price, and capabilities are increasing. As it does not require film and the image can be seen on the screen instantly, its demand is increasing at a huge rate. In the near future it may turn the film camera into a museum piece.
A webcam is a special type of video camera that can be connected to a computer via USB to share video over the Internet. The webcam was invented at Cambridge University in 1991. Since the 21st century, laptop manufacturers have started adding webcams to laptops.
Barcodes are a visual method of collecting information. Which is done by machine. It usually provides various information about the things it contains. A traditional barcode is a series of drawn parallel lines—with varying widths and spaces between them—that represent different information; It is linear or one-dimensional system. Later, barcode systems based on rectangles, dots, hexagons and other geometric structures began to be used.
Also known as matrix code or two-dimensional barcode. Although it does not actually use bars or straight lines. Initially barcodes were scanned with special optical scanners called barcode scanners. Later, software was developed that could read images captured by smartphones equipped with cameras.
Norman Joseph and Bernard Silver invented the barcode. It was patented in the United States in 1951 (US2612994A). This invention was based on Morse code, which was an adaptation of thin and thick dots. However, it took twenty years to become a commercial success. Early industrial use of barcodes was encouraged by the Association of American Railroads in the late 1960s.
Developed by General Telephone & Electronics and Cartrack ACI, the project involved giving colored stripes on steel to railway rolling stock. One plate was used on both sides of a vehicle. It contained details of ownership, vehicle type, identification marks.
Those plates were detected by a truckside scanner. For example, when the vehicle entered the yard in motion. The project was abandoned after ten years. Because the system was not reliable due to long-term use.
Audio Data Entry Mechanism: –
- Midi Keyboard
What is microphone?
A microphone is a type of device, colloquially called a mic. It acts as a type of sensor, which converts sound energy into electrical energy. As a result, communication through wires is possible.
It is widely used in computers, mobile phones, audio recorders, hearing aids, megaphones, radio or television broadcasting stations etc. Most modern microphones generate electrical signals using electromagnetic induction, changes in capacitance, the piezoelectric effect, or air pressure differences.
- Digitize pen
Central Processing Unit (CPU) :-
- পেন্টিয়াম ১
- পেন্টিয়াম ২
- পেন্টিয়াম ৩
- পেন্টিয়াম ৪
- পেন্টিয়াম ৪ ইক্সট্রিম
- পেন্টিয়াম ডি
- পেন্টিয়াম ইক্সট্রিম এডিশন
- পেন্টিয়ামডুয়াল কোর (Dual Core)
- কোর ডুয়ো
- কোর ২ ডুয়ো
- কোর ২ কোয়াড
- কোর ২ ইক্সট্রিম
- I – Core
- Core i3
- Core i5
- Core i7
- Core i9)
- Centrino 2
- Centrino Duo/Solo
- AMD(Advance Micro Processor) Processor
- Phenom II X6
- Phenom II X4
- Phenom II X3
- Phenom II X2
- Phenom I X3
- Phenom I X4
- Turion II Ultra
- Turion II
- Athlon II X2
- Athlon Neo X2
- Athlon Neo
RAM (Random Access Memory)
- FPM DRAM
- EDO DRAM
- DDR SDRAM
- Credit Card Memory
- PCMCIA Memory Card
- CMOS RAM
- ROM(Read Only Memory)
- Flash Room
- Video Card
- PCI Express
- Network Components
- Network Card
- Line Printer
- Daisy Wheel
- Dot Matrix Printers
- Inkjet Printers
- Laser Printers
- Snapshot Printer
- Thermal Wax Printer
- Head Phone
- Monitor (Visual Display Unit)
- Liquid Crystal Display
- Cathode Ray Tube)
- TTL monitor
- Touch Screen
- light-emitting diode
- Organic Light-Emitting Diode
- IO Structure
- Expansion bus cards and slots
Data storage device:-
1. Primary Memories
2. Auxiliary Memory
– Optical/CD/DVD/BD ROM
– Rewritable CD/DVD
– Writable Blue-ray
– HD DVD
3. Floppy disk
4. USB flash drive
– Pen Drive
-External hard drive
5. Tape drive
9. Paper tape
10. Magnetic Tape
11. Punch card
What is motherboard ?
The motherboard is the “brain” of a computer. Components are attached directly to the motherboard. The computer is ready with the essential components, namely:
The central processing unit (in English Central Processing Unit or CPU) performs most of the calculations required to operate the computer and perform various tasks.