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System software

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System Software (2.2)

Information Technology 9626

Compilers, Interpreters, Linkers, Device Drivers, and Operating Systems

Interactive Revision Notes with Self-Testing

What is System Software?
High-Level Languages and Machine Code
Compilers
Interpreters
Comparing Compilers and Interpreters
Linkers
Device Drivers
Operating Systems and Their Functions
Summary and Review

1. What is System Software?

Learning Objectives:

Understand what system software is and why it's needed
Know the different types of system software
Understand the relationship between system and application software
Learn how system software enables communication between applications and hardware

Definition of System Software

System Software: Programs that run and control a computer's hardware and application software. System software manages the computer's resources and enables application software to run on different hardware platforms.

Types of System Software

Main Types of System Software:

Compilers - Translate high-level code to machine code
Interpreters - Translate and execute code line-by-line
Linkers - Combine multiple code modules into one executable
Device Drivers - Enable communication between OS and hardware
Operating Systems - Manage hardware, software, and user interaction
Utilities - Help maintain and manage the computer system

Why System Software is Needed

The Problem: Programmers can't write applications directly in machine code (binary 1s and 0s). This would be extremely difficult, error-prone, and tedious.

The Solution: System software translates human-readable programming languages into machine code that computers understand. It also manages hardware resources, allowing applications to run without worrying about low-level hardware details.

Quick Question 1

Why is system software essential for a computer to function properly?

2. High-Level Languages and Machine Code

The Problem: Machine Code

Machine Code: Binary instructions (1s and 0s) that a computer's processor directly understands and executes. Each instruction is a number written in binary.

Machine code is extremely difficult for programmers to work with because:

Instructions are just numbers (e.g., 10110101)
Hard to remember what each number means
Easy to make mistakes
Very tedious to write large programs

The Solution: High-Level Languages

High-Level Language: A programming language that uses human-readable commands and statements, making it easier for programmers to write and understand code compared to machine code.

History of High-Level Languages

Early Programming Languages

FORTRAN (Formula Translation): First high-level language, developed in the 1950s. Very mathematical in nature. Still used today by physicists for simulating large physical systems (modeling stars and galaxies).

COBOL (Common Business-Oriented Language): Developed after FORTRAN for business use. Uses simple English-like expressions: SUBTRACT money FROM account GIVING balance instead of mathematical equations. Still used in banking mainframes (ATMs use COBOL).

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Also in the full note

3. Compilers
4. Interpreters
5. Comparing Compilers and Interpreters
6. Linkers
7. Device Drivers
8. Operating Systems and Their Functions
9. Summary and Review
System Software: Complete Overview

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