Computer Fundamentals: CPU and Memory

Study Notes

Computer Components and Their Functions

Retains information without power; used to hold program instructions and data.
Central Processing Unit (CPU) functions as the brain of the computer, making key decisions and controlling operations.
CPU consists of two main parts: the Arithmetic Logic Unit (ALU) and the Control Unit.
Arithmetic Logic Unit (ALU) executes arithmetic and logical operations, handling data stored in primary storage temporarily.
Control Unit manages data transfers and instructions among other units, coordinating operating functions and communicating with Input/Output devices.
Output Unit converts coded results from the computer to human-readable formats using devices like monitors and printers.

Hardware and Software

Computer systems comprise hardware (physical components) and software (commands for hardware).
Software classified into system software, which runs and manages computer operations, and application software.
High-Level Languages simplify programming and do not require extensive hardware knowledge, making programming more accessible.

Examples of High-Level Programming Languages

BASIC: Easy to learn general-purpose language, mainly for microcomputers.
COBOL: Standardized language for commercial applications.
FORTRAN: Developed for scientific and mathematical tasks, popular in scientific communities.
C: Versatile language for diverse applications including scientific, commercial, and game development.
C++: Object-oriented language used generally.

Programming Language Translators

Compilers convert high-level language source code into machine language.
Interpreters execute high-level language statements one at a time, converting each before execution.
Assemblers translate assembly language into machine language.
Linkers combine object files generated by compilers into executable files.

Introduction to C Programming

C, developed in 1972 at Bell Laboratories by Dennis Ritchie, is a structured programming language initially for UNIX implementation.
ANSI standardized C programming in 1983 to provide a modern definition.

Popularity and Characteristics of C

C is reliable, simple, portable, and has a vast assortment of operators.
It allows greater freedom in data storage while not enforcing strict data type checks.
Dominant in developing applications for minicomputers and personal computers, widely used for systems like word processors and compilers.

Structure and Syntax of a C Program

C programs must follow a defined structure including header files, main function, and code blocks.
Example given includes basic input/output operations using the #include directive and functions like printf and scanf.

Real and Character Constants

Rules for real constants:
- Must include at least one digit and a decimal point.
- Can be positive or negative, with no commas or blanks.
Exponential constants are expressed with 'e' for mantissa and exponent separation.
Character constants consist of single characters within single quotes and can only be one character long.

Variables in C

Variables are named storage locations for values that can change over time but hold one value at a moment.
Each variable is associated with a data type (e.g., int, char, float) that defines the possible values.
Example variable declarations include int page_no, char grade, float salary, and long y.
Variables can be declared at the start of a block of code or before function names.

Description

This quiz tests your knowledge on computer fundamentals, focusing on memory retention and the role of the Central Processing Unit (CPU). Understand how data and program instructions are managed when systems are powered off and learn about the CPU's functions in processing information. Ideal for students looking to reinforce their understanding of basic computer architecture.