Digital Age Essentials: Computers and Peripherals
What is the Digital Age?
The digital age is the massification of technology in our lives.
What is a Computer?
A computer is an electronic machine capable of solving high-speed operations for the benefit of man.
Computers in Banks and Schools
In banks, computers store information, enable staff to access large databases, and carry out financial transactions at high speed.
In schools, they are used to access the internet, do basic research, give presentations, and write letters.
Hardware vs. Software
Hardware refers to the physical parts you can see or touch. Software refers to the programs which can be used on a particular system.
Three Main Sections of Hardware
- CPU (Central Processing Unit): Executes program instructions and coordinates the activities of all the other units.
- Main Memory: Holds the instructions and data which are being processed by the CPU.
- Peripherals: The physical units attached to the computer.
Classification of Peripherals
- Input devices: Connect to the computer to enter information.
- Output devices: Extract information from a computer.
- Storage devices: Used to store information.
Function of Storage Devices
Provide permanent storage of both data and programs (e.g., hard drives, DVD drives, flash drives).
Function of Ports
Ports allow us to plug in a wide range of peripherals.
Input and Output Devices
Input devices: Enable data to go into the computer’s memory.
Output devices: Enable us to extract the finished product from the system.
RAM and ROM
RAM: Random Access Memory.
ROM: Read Only Memory.
Three Main Parts of the CPU
- The Control Unit
- The Arithmetic Logic Unit
- The Registers
Function of the System Clock
Sends out signals at fixed intervals to measure and synchronize the flow of data.
BIOS
BIOS: Basic Input/Output System. It uses ROM to control communication with peripherals.
Buses
Electrical channels which allow devices inside the computer to communicate with each other.
Bus Width
Determines how much data can be transmitted at once.
Bit vs. Byte
A bit is the basic unit of information and can have a state of 1 or 0. A byte is a representation of information consisting of 8 bits.
Laptop vs. Desktop
“I do not need a computer that is very powerful, because I need it for the most basic tasks. I work and study, so I need to take it everywhere with me. Therefore, I prefer a laptop because it is lightweight and I can carry it anywhere.”
Common Peripherals
- Mouse: Moves the cursor on the screen, allowing interaction with elements.
- Keyboard: Inputs data for processing.
- Printer: Creates a paper copy of digital files.
- Scanner: Converts physical documents/images into digital formats.
- Monitor: Displays the computer’s output.
- Game Controller: Used to interact with video games.
- Microphone: Captures sound for input.
Types of Scanners
- Flatbed scanner: Used to scan images or plain texts.
- Handheld scanner: For scanning text, bar codes, and handwritten numbers.
- Slide scanner: Allows you to scan multiple formats of transparent film (negative, positive, color, or black and white).
Display Technologies
- LCD: Liquid Crystal Display.
- CRT: Cathode Ray Tube.
- OLED: Organic Light Emitting Diode.
Resolution
Refers to the number of dots of color, known as pixels, contained in a display.
Screen Size Measurement
Screen size is described by two measurements: the aspect ratio and the diagonal screen size.
Aspect Ratio
Describes the proportional relationship between a display’s width and height.
Types of Printers
- Dot-matrix: Use pins to print dots to form characters.
- Inkjet: Project small ink droplets onto paper.
- Laser: Scan the image with a laser beam and transfer it to paper with toner.
- Thermal transfer: Produce color images by transferring wax-based ink onto paper.
- Image setters: Expose rolls or sheets of photographic film or bromide paper to a laser.
Laser printers generally offer the best resolution for text and graphics.
Multifunction Printer
An office machine which incorporates the functionality of multiple devices in one (e.g., printing, scanning, copying).
Printer Speed
Measured in pages per minute (ppm).
Disc vs. Disk
A disc refers to optical media (e.g., CD, DVD). A disk refers to magnetic media (e.g., floppy disk, hard drive).
Magnetic Storage
Data is stored by magnetizing particles on a disk or tape.
Types of Magnetic Storage
Floppy disk, hard drive, tape.
Capacity of a 3.5” Floppy Disk
1.44 MB
Seek Time vs. Transfer Rate
Seek Time: The average time required for the read/write heads to move and find the data.
Transfer Rate: The average speed required to transmit data from the disk to the CPU.
Head Crash
Occurs when the read/write head touches the rotating disk, potentially damaging the disk surface.
Protecting Your Hard Drive
- Don’t hit or move the computer while the hard drive is spinning.
- Check your hard drive regularly for logical and physical errors.
- Install an up-to-date virus scanner.
Flash Memory
Named for its speed, as it can be erased “in a flash.”
CD and DVD
CD: Compact Disc. DVD: Digital Versatile Disc. They differ in capacity and internal structure. Formats include: CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-R, DVD+R, DVD-RW, DVD+RW.
DVD Recorder vs. DVD Burner
A DVD Burner records information by burning via a laser to a blank DVD. A DVD Recorder typically refers to a standalone unit resembling a VCR.
Optical Storage
Devices that store data using a laser beam on a plastic surface.
Computer Access for Mobility Limitations
Individuals can use expanded or ergonomic keyboards, on-screen keyboards, adaptive switches, and voice recognition systems.
Computer Access for Deaf Individuals
Visual alerts, electronic notetakers, and text phones can be used.
Computer Access for Blind Individuals
Technologies such as Braille keyboards and embossers, screen magnifiers, speech synthesis, and optical character recognition are used.
Assistive Technology Examples
- Braille keyboard: Allows blind users to identify each key.
- Braille embosser: Produces tactile Braille symbols.
- Eyegaze system: On-screen keyboards activated by eye movements.
- Screen magnifier: Enlarges the screen image.
- Textphone: Allows deaf individuals to type and read phone conversations.
- Sip-and-puff systems: Control the PC by puffing and sipping air.
Laptop Comparison
Acer vs. Samsung:
- The Acer is more powerful for special programs.
- The Acer is faster for processing large amounts of information.
- The Acer is heavier for frequent travel.
- The Acer is more expensive than the Samsung.
- The Samsung NP530 is cheaper than other laptops.
- The Samsung is better for home work.
- The Samsung is thinner than others at the same price point.
Screen Comparison
- One screen is bigger than others in the same price range.
- One screen is more expensive but worth the price.
- One screen is cheaper but of very good quality.
- One screen is smaller and lighter than other LEDs.