Sskills Computar - Ro-ràdh

### Compscoil Skills - Introduction

•  A computer accepts input, stores it temporarily in memory, processes it, and then transfers the processed data to an output device.
• Data is raw, unorganized facts.
• Information is processed data, organized to be meaningful.
•  Hardware refers to the physical parts of a computer.
•  Software are instructions that tell the computer hardware what to do. These are programs.

### Computer Hardware

•  Internal hardware is located inside the computer's main box.
• External hardware connects to the computer, often via wired or wireless connections.
•  Input devices: Keyboard, mouse, scanner, camera, touchscreen, etc.
•  Output devices: Monitor, printer, speakers, projector, etc.
• Processing devices: CPU (Central Processing Unit) performs calculations and controls the computer's operations.
• Storage devices: Hard drives, CDs/DVDs, USB flash drives, etc., used to store data.
• Communication devices: MoDems, network adapters, etc.,allow communication with others online.

Computer Software

•  Software tells the computer what and how to perform tasks.
•  System software: Main software that starts up and controls the computer's operations.(Examples include operating systems like Windows, Linux.)
• Utility programs: Analyze, configure, optimize, and maintain the computer.
•  Application software is used for specific tasks (Examples include word processors, web browsers, multimedia programs.)
• The System Unit is the main housing for the computer's processing hardware, including memory, power supply, cooling fans, and storage devices.  

The Motherboard

• The motherboard is the main circuit board.
•  It contains computer chips (silicon pieces), circuits (connections), and other electronic components.
•  All computer components must connect to the motherboard.

Primary Components of a Computer

• Input devices: Accept data from the user and prepare it for processing.
• Output devices: Provide results to the user in a human-readable format(e.g., text, graphics).

The CPU

• CPU (Central Processing Unit) is the "brain" of the computer.
• Contains electronic circuits that perform processing tasks.
• Interprets, processes, and executes instructions.
• Includes different cores for parallel processing to improve speed. (e.g., dual-core, quad-core CPUs)

Memory (RAM)

• RAM (Random Access Memory) is temporary storage.
• Used to hold data and instructions requiring immediate access.
• Volatile: Data loss when power is off.
• Range: 256MB to 16GB.

Memory (ROM)

• ROM (Read-Only Memory) is non-volatile storage.
• Stores essential instructions that operate when the computer starts.

Secondary Storage Devices

• Secondary storage devices are for permanent storage of data.
• Magnetic storage: Hard drives, floppy disks.
• Optical storage: CDs, DVDs.

Memory Hierarchy

• Registers are inside the CPU.
•  Cache memory is faster than main memory but smaller.
• Main memory is relatively fast and stores data needed soon.
• Mass storage (hard drive) is large and permanent, but slower.
• Cost vs capacity: Cost increases as capacity increases. Faster memory tends to be more expensive.

Basic Units of Measurement

• Bit (Binary digit): 0 or 1.
• Byte: 8 bits.
• Kilobyte (KB), megabyte (MB), Gigabyte (GB), Terabyte (TB), etc.. represent increasing capacities.

Buses (Structure of a Microcomputer)

• Buses are electronic paths for data transfer between parts of a computer.
• Types of buses include: Address bus, data bus, and control bus.

Ports and Connectors

• Ports are connections on the outside of a computer system for devices.

How the CPU Works

• Consists of many transistors and circuits.
•  A key element of modern CPUs is the transistor.
• The number of transistors in a CPU doubles roughly every 18 months.
• Typical CPU components: ALU, FPU, CU, Prefetcher, Decoder, Internal Cache, and Registers.

Operating Systems

• A collection of programs that manage the coordinated activities of a computer system.
• Functions: Interfacing with the user, managing resources, booting the system, configuring devices, file management.

Computer Languages

•  Low-level languages (e.g., machine code, assembly): Close to how the hardware operates.
•  High-level languages (e.g., Fortran, Pascal, C++, Java): Closer to natural language, making them easier for humans to use.
•  Assembly: Symbolic representation of machine code, more efficient.
•  High-level language: Consisting of English-like keywords. (e.g., Print, IF-THEN-ELSE).

High-level Language (structured)

• Structured design: Dividing a problem into smaller subproblems.
• Structured programming: Implementing a structured design.
• Stepwise refinement: Designing a system in modules.

High-level Language (OOP)

• Object-oriented programming (OOP): Identifying components (objects), combining data and operations into a single unit, specifying relevant data.