Computer Fundamentals: Components, Operation, and Data Storage

Posted on Nov 23, 2024 in Technology

What is a Computer? A computer is an electronic machine used to process digital information. Digital information is expressed in terms of 0 and 1, i.e., in binary numbering.

Basic Operation

  1. We provide input data to the computer in digital format.
  2. The computer processes these inputs according to the program instructions being executed. This is mainly carried out by the microprocessor (CPU), but also involves:
    • RAM: Temporarily storing data and instructions.
    • Graphics Card: With its own processor and RAM.
    • Chipset: Controls data flow between components.
  3. The computer produces output data, which can be displayed, printed, or stored.

Hardware and Software

A computer is hardware, which needs software to function. Digital information is converted into electrical impulses (e.g., 0 volts for 0 and 5 volts for 1). Software includes:

  • Operating Systems (Windows, Linux, macOS).
  • Applications (word processors, spreadsheets, etc.).

Each application is designed for a specific operating system.

Digital Information

To convert a decimal number (e.g., 150) to binary, divide by 2 successively and write the remainders in reverse order. The basic unit of digital information is the Bit. A set of 8 bits is a Byte.

  • 1 Kilobyte (KB) = 1,024 Bytes (~1000 Bytes).
  • 1 Megabyte (MB) = 1,024 KB = 1,048,576 Bytes (~1 million Bytes).
  • 1 Gigabyte (GB) = 1,024 MB = 1,048,576 KB = 1,073,741,824 Bytes (~1 billion Bytes).

Inside the PC

Key parts inside the computer case include:

  • Power Supply
  • Motherboard (with microprocessor, RAM, graphics card, sound card)
  • Hard Drive
  • (Formerly) Floppy Disk Drive (3 ½)
  • Optical Drive (CD-ROM or DVD)

Power Supply

Converts AC to DC, reduces voltage, and has a fan for cooling. May include a monitor outlet and a power switch.

Motherboard

The main circuit board connecting all components.

Microprocessor

An integrated circuit that processes data and instructions from RAM. Features include clock frequency, number of transistors, and bit number.

RAM

Temporarily stores programs and data. Physically, it’s a printed circuit with chips, connecting to the motherboard via a slot. Characteristics include storage capacity, memory type, and speed.

Graphics Card

Converts processed information into a display signal. Features include graphics processor and memory.

Hard Drive

A permanent storage device using magnetic disks. Data is read/written by heads. Disks spin at high speed, with a tiny gap between head and disk (about 1 micron). Moving parts are protected within a metal housing.

Hard Disk Maintenance

Fragmentation occurs when files are not stored contiguously, slowing down access. Use the Disk Defragmenter to optimize storage. Hard drive features include storage capacity, interface type, access time, and spin speed.

Optical Drives

Read/write data using a laser beam. Types include:

  • CD-ROM: Reads CD-ROM, CD-R, and CD-RW.
  • CD-RW Recorder: Reads and records CD-R and CD-RW.
  • DVD Player: Reads CD-ROM, DVD, DVD-R, DVD+R, DVD-RW, and DVD+RW.
  • DVD Recorder: Reads and records DVD-R, DVD+R, DVD-RW, and DVD+RW (including dual-layer discs).
CD and DVD Discs

Both CDs and DVDs are 120mm in diameter and 1.2mm thick, with a 15mm central hole. A CD-ROM has a polycarbonate base, a metal layer for data, and a protective lacquer coating. DVDs have a similar structure but higher data density.

How Information is Stored

Digital information is stored as marks of different sizes in a spiral track. DVDs have a tighter spiral and smaller marks, allowing for higher storage capacity (4.7GB for a single-layer DVD vs 700MB for a CD).

Optical Drive Functioning
  1. A laser diode emits a beam onto the disc.
  2. The beam is reflected differently depending on whether it hits a mark or an unmarked area.
  3. Mirrors and lenses direct the reflected beam to a sensor.
  4. The sensor distinguishes between different light reflections and converts them into electrical impulses (0s and 1s).
Recording Speed

Features include read/write access time and data transfer rate.

Sound Card

Functions:

  • Converts digital audio to analog signals for speakers.
  • Records analog audio to digital files.

It’s a printed circuit board with components like DSP, ADC, DAC, RAM, and ROM. Modern motherboards often have integrated sound, but a dedicated sound card can provide better audio quality.

RAM is where your computer stores programs and data temporarily and are erased when switched off, insert Physically is a rectangular printed circuit with multiple chips, which attaches to the motherboard via a specific slot. Characteristics are the ability to store data, type of memory, speed of work, etc.