Computer Chapter 2: Input and Output Devices

Chapter 2: Input and Output Devices

• Peripheral devices facilitate communication between the computer and the external world
• Input Devices supply data/programs to the computer (e.g., keyboard, mouse)
• Output Devices relay computer-generated information to users or storage (e.g., monitors, printers)
• I/O Interfaces convert input data into machine-readable form, and output into human-readable form
• Data Input Methods include On-line (direct transfer) and Off-line (data prepared and entered later)

2.2 Input Devices

2.2.1 Punch Cards

• Data stored in cards using codes (e.g., Hollerith Code)
• Advantages: Cheap, reliable
• Disadvantages: Not reusable, require careful handling and large storage.

2.2.2 Keyboard

• Standard input device; easy to use, inexpensive
• Keys: Letters, numbers, special functions (e.g., F1-F12, arrow keys)
• Allows efficient data editing

2.2.3 Mouse

• Pointing device for cursor movement
• Types: Mechanical, optical, optical-mechanical
• Used for writing/sketching on screens

2.2.4 Light Pen

• Used for writing/sketching on screens
• Applications: CAD

2.2.5 Joystick

• Converts movement into digital signals; used in gaming

2.2.6 Trackball

• Sphere-based device for cursor control

2.2.7 Touchscreen

• Transparent plate over CRT; registers touch input
• Types: Optical and electric

2.2.8 Digitizer

• Converts graphical/pictorial data into digital form
• Types: Image scan and flatbed digitizers

2.2.9 Scanner

• Types: Optical (OMR, OCR) and Magnetic Ink Character Recognition (MICR)
• Reads text/images directly into memory

2.2.10 Voice Recognition

• Converts speech to electrical signals
• Advantages: Reduces data entry cost, operator mobility
• Disadvantages: Operator-dependent, requires pre-stored vocabulary

2.3 Output Devices

2.3.1 Printers

• Impact Printers: Use mechanical hammers (e.g., dot matrix, daisy wheel, line printers)
• Non-Impact Printers: Use modern technologies (e.g., inkjet, laser)

2.3.2 Plotter

• For graphs/drawings
• Types: Flatbed (X-Y) and Drum

2.3.3 Video Display Terminal

• Types: CRT, Flat Panel Display (e.g., LCD, plasma screens)
• Terminal types: Dumb, smart, intelligent

2.3.4 Computer Output Microfilm (COM)

• Records data as microscopic images on film
• Advantages: Space-efficient, high-speed
• Disadvantages: Expensive, sophisticated

2.4 Summary

• Peripheral devices are categorized into input and output types
• Input devices capture user data (e.g., keyboards, mice, scanners)
• Output devices present processed data (e.g., printers, monitors)
• Advanced I/O devices enhance interaction and efficiency

2.5 Questions for Self-Study

• Fill in the blanks: Example of a picking device, pointing device, digitizer
• Give full forms: MICR, OCR, OMR
• Match the following: Punch card - Hollerith Code, Bar code- Universal Product Code, Joystick- Computer games, Floppy Disk - Output devices.
• Short answers: Define terminal and list types, What is an impact printer? Name an example.

This quiz covers Chapter 2 on Input and Output Devices, discussing how peripheral devices aid communication between computers and users. It explores various types of input devices, including keyboards and mice, and the concept of I/O interfaces and data input methods.