C4B Understanding System Units and I/O Components

Digital Electronic Signals

Digital Electronic Signals

Signals recognized by computers for processing.

Analogue Signals

Continuous signals created by natural phenomena.

Conversion

Process of changing analogue to digital signals.

Bit

Smallest unit of data, representing 0 or 1.

Byte

Group of 8 bits used for data representation.

Hexadecimal System

Base-16 system using digits 0-9 and A-F.

ASCII

7-bit character encoding for personal computers.

EBCDIC

8-bit character encoding for mainframe computers.

Unicode

16-bit encoding supporting over 65,000 characters.

Input Devices

Hardware that translates data for processing.

Keyboard

Input device for entering letters and symbols.

Pointing Device

Controls cursor movement on the screen.

Optical Mouse

Mouse using light to detect movement.

Wireless Mouse

Mouse operating via radio or infrared signals.

Touch Screen

Display that accepts input via touch.

Gaming Controllers

Devices providing input for computer games.

Scanner

Device converting scanned data for processing.

Card Reader

Interprets information from credit or ID cards.

Bar Code Reader

Scans barcodes for product identification.

RFID Reader

Reads information from RFID tags remotely.

Multi-Function Device (MFD) (All-in-one printer)

Combines printing, scanning, and copying functions.

Virtual Keyboard

On-screen keyboard for input on touch devices.

Stylus

Pen-like device for input on touch screens.

Trackball

Pointing device with a movable ball.

3D Scanner

Captures three-dimensional objects for processing.

Motion Sensing Device

Controls games based on user movements.

RFID Readers

Devices that read electronically stored information remotely.

Optical Character Recognition (OCR)

Technology to read printed characters and convert to text.

Magnetic Ink Character Recognition (MICR)

Reads special ink used in checks and bank documents.

Optical Mark Recognition (OMR)

Detects marks on forms, commonly used in test scoring.

Webcams

Capture images and stream them over the internet.

Digital Cameras

Capture and store images digitally for later use.

Voice Recognition Systems

Allow users to control devices using voice commands.

Output Devices

Present processed data to users in various formats.

Monitors

Display visual images of text and graphics.

Cathode Ray Tube (CRT)

Older monitor technology using electron beams.

Liquid Crystal Display (LCD)

Flat-panel monitor technology using liquid crystals.

Light Emitting Diode (LED)

Advanced backlighting technology for flat-panel displays.

Organic Light Emitting Diode (OLED)

Thin display technology using organic compounds for light.

E-book Readers

Devices for storing and displaying electronic books.

Digital Projector

Projects images from a computer onto a larger screen.

Ink-jet Printers

Print using tiny droplets of ink for high-quality output.

Laser Printers

Use laser beams for fast, high-quality printing.

3D Printers

Create three-dimensional objects layer by layer.

Cloud Printers

Allow printing from any network-connected device.

Plotters

Printers that create line drawings on large paper.

Bluetooth Technology

Wireless technology for connecting devices over short distances.

Headsets

Combine microphone and headphones for audio input/output.

Virtual Reality (VR)

Simulated reality using head-mounted displays and controllers.

Drones

Unmanned aerial vehicles with various sensing capabilities.