Computer Fundamentals: Data, Components, and System Operations
Data Representation and Number Systems
Converting Binary to Decimal Numbers
To convert a binary number into a decimal number, you multiply each digit by increasing powers of 2, starting from the rightmost digit (20).
Converting Decimal to Binary Numbers
To convert a decimal number into a binary number, you repeatedly divide the decimal number by 2 and record the remainders in reverse order.
Fundamental Units of Information
What is a Bit? And a Byte?
- Bit: The smallest unit of information that can be stored on a computer (represented by 0 or 1).
- Byte: A group of 8 bits that makes up a single byte.
Hardware and Software Components
Defining Hardware and Software
- Hardware:
- It refers to the physical components of the computer system. It is everything we can touch, move, and see. Examples: mouse and keyboard.
- Software:
- It refers to the programs and instructions that run on the hardware. There are various types of software:
- Operating Systems
- Applications
- Programming Languages
What is ASCII Code?
ASCII (American Standard Code for Information Interchange) is used to represent all characters on computers. Each character (letter, number, symbol) is represented by a group of 8 bits (1 byte).
The Motherboard: Central Hub
What is the Motherboard and Its Purpose?
The motherboard is the physical support structure for essential computer elements. It facilitates communication among different components through sets of copper wires called buses.
Key Elements Supported by the Motherboard:
- Microprocessor
- Memories
- Slots
- Ports
- Connectors
Computer Memory Systems
Understanding Computer Memories (ROM BIOS)
When you turn on your computer, it automatically checks the system. This initial check is carried out using instructions stored in a special read-only memory: the ROM BIOS (Basic Input/Output System).
Storage Devices and Examples
Different Types of Storage Devices
Storage devices are categorized based on the technology they use:
- Magnetic Devices: The Hard Disk Drive (HDD) is the most common magnetic storage unit.
- Optical Discs: CD-ROMs, DVDs, and Blu-ray discs store data in a series of grooves on the disc surface.
- Solid State Devices (Flash Memory): These devices use transistors acting as switches to store data. Example: USB flash drives.
The Operating System (OS)
What is an Operating System?
An Operating System (OS) is software that manages computer resources and provides common services for other software that runs “on top” of it.
Functions of the Operating System
The OS performs critical management tasks, including:
- Managing the microprocessor (CPU).
- Managing memory and storage systems.
How an Operating System Works: Application Execution
- The operating system finds the application on the hard disk, sends a copy to the RAM (Random Access Memory), and loads it onto the screen.
- The program becomes the active application. It receives data from the keyboard and sends instructions to the microprocessor through the operating system.
- When the user saves the document, the operating system looks for free space on the hard disk and transfers the data from the memory to that space.
- To print, the word processor sends the command to the operating system, which then sends the appropriate signals to the printer.
- When the application is closed, the operating system deletes the application from the memory, though not from the hard disk.
Hard Disk Structure and Partitions
Physical Structure of a Hard Disk
A sector is the smallest addressable unit of data exchange between a disk drive and memory. The most usual size is 1024 bytes (on both sides of the sector).
Understanding Disk Partitions
A primary partition is a section of the disk where an Operating System can be installed. Since there can be up to four primary partitions with four different Operating Systems installed, one partition is marked active and is used for the initial booting process. The active partition contains the boot loader.