Computer Components Overview

Study Notes

A computer system comprises two main components: hardware and software.
Hardware refers to the physical equipment of the computer.
Software consists of a collection of programs that manipulate the hardware to perform tasks.

Central Processing Unit (CPU): The brain of the computer where most calculations take place.
Primary Memory: Volatile memory that temporarily stores data and instructions.
Secondary Storage: Non-volatile storage devices like hard drives and SSDs for permanent data retention.
Input System: Devices like keyboards and mice that allow users to input data.
Output System: Devices such as monitors and printers that display or produce output.
Communication System: Facilitates data exchange between computers and networks.

System Software: Manages hardware resources and includes operating systems and utility programs.
Application Software: Divided into general-purpose software (e.g., word processors) and application-specific software tailored for particular tasks or industries.

Machine Languages: Binary code comprehensible only by a specific computer.
Symbolic Languages: Developed in the 1950s, utilizing mnemonic symbols for easier programming, e.g., assembly language.
High-Level Languages: Abstract languages like FORTRAN and COBOL created to enhance programmer efficiency and portability across systems.

Four main programming paradigms:
- Procedural: Focuses on procedure calls.
- Object-Oriented: Organizes software design around data, or objects.
- Functional: Treats computation as the evaluation of mathematical functions.
- Logic: Based on formal logic and rules.

C++ is built on the procedural paradigm but supports object-oriented programming through classes and objects.
Early chapters focus on procedural aspects, utilizing object-oriented features primarily for input/output operations.

Involves two key steps:
- Understanding the problem: Review requirements and consult with users for clarification.
- Developing a solution: Outline algorithms and transformations for input to output.

UML serves as a standardized tool for designing, specifying, and documenting aspects of computing systems, particularly in object-oriented programming.

Writing and Editing: Uses text editors to create and modify source files containing code.
Compiling: Source files are translated into machine language through a compiler.
Linking: Combines user-defined functions with system functions into an executable program.
Executing: Loads the program into memory for processing input and generating output.

Ensures program correctness by testing all instructions and scenarios.
Test data must be created throughout design and development phases to verify and validate the program.

Three classifications of errors:
- Specification Errors: Occur due to incorrect or misunderstood problem definitions.
- Code Errors: Result in compiler messages, often straightforward to fix.
- Logic Errors: Difficult to detect and correct errors that arise from faulty program logic.