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Computer Science IGCSEPDF 50
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Utility programs maintain, secure, and optimize computer performance. They usually run within
or alongside the OS.
Examples:
Utility Program
Function / Purpose
Antivirus Software
Detects, prevents, and removes malware.Must be updated
regularly.
Reorganizes fragmented HDD files for faster access (not
needed for SSDs).
Reduces file size; may be lossless (reversible) or lossy
(irreversible).
Creates copies of data on external drives or cloud for
recovery.
Removes temporary or duplicate files to free space.
Disk Defragmenter
File Compression Software
Backup Software
System Cleanup / Disk
Analysis
Encryption Tools
Automatic Updates
Converts data into coded form to prevent unauthorized
access.
Keeps OS and applications up to date with security patches.
4.4 Interrupts and Buffers
A. Interrupts
Definition: A signal sent to the CPU by hardware or software requesting immediate attention.
Purpose: Ensures urgent events (key press, power failure, device completion) are handled
instantly.
Process:
1.
Interrupt occurs (e.g., printer runs out of paper).
2.
CPU pauses current process and saves its state.
3.
Interrupt handler identifies priority.
4.
CPU executes the Interrupt Service Routine (ISR).
5.
CPU restores the saved state and resumes its task.