PAPER 1 PROGRAMMING
EXAM 2024
OS Utility Programs
OS:
User Interface
Memory management
Processor management
Peripheral management
Storage device management
Disk and file management
Application management
Managing security
Access rights
,UTILITY SOFTWARE:
Anti-virus software
Spyware protection
Firewall software
Automatic software update
Backup utilities
File management
Repairing corrupted files
Saving files on disk
Disk defragmentation
Abstraction - ✔✔✔ANSWER-The removal of unnecessary information to make a
problem easier to understand
Access rights - ✔✔✔ANSWER-If a computer is used by more than one person,
each user should be able to see only their own files
Users and system administrators have different levels of access rights
Some users may be allowed to read files but not edit them
Accessing an element in the array - ✔✔✔ANSWER-num[0] (= 1)
ADC - ✔✔✔ANSWER-Analogue to digital convertors. Sounds must be converted
into a digital form in order to be stored and processed by a computer
ADC example - ✔✔✔ANSWER-Microphone
,Advantages of Local variables - ✔✔✔ANSWER-- Good practice as it keeps the
subroutine self contained
- The program will be easier to debug and maintain
- Saves memory
Advantages of Subroutines - ✔✔✔ANSWER-- Breaks down a large problem into
more manageable sections (decomposition)
- Each subroutine can be tested individually
- Can be used many times in one program
- Allows several programs to work together by giving 1 subroutine to each of them
- makes it easier to change your code
Algorithm - ✔✔✔ANSWER-A methodical, logical rule or procedure that
guarantees solving a particular problem.
ALU - ✔✔✔ANSWER-Arithmetic and Logic Unit -
Logical operations (AND, OR)
Shift operations
Arithmetic operations (Simple maths)
AND gate - ✔✔✔ANSWER-A logic circuit whose output is 1 when all inputs are
1
Looks like a D
Input A , Input B - Output
0,0-0
0,1-0
, 1,0-0
1,1-1
Anti-virus software - ✔✔✔ANSWER-Prevents viruses from being installed
Prevents system files being deleted or changed
Detects and removes viruses that do manage to install themselves
*New viruses are always being invented so anti-virus software must be regularly
updated*
Application management - ✔✔✔ANSWER-When you install a new application on
your computer, the OS will run a program to install it
The OS will interact with applications through an Application Programming
Interface (API)
The API allows the application to communicate with the OS
Arguement - ✔✔✔ANSWER-An argument is the actual value being passed into a
subroutine.
Arithmetic Operators - ✔✔✔ANSWER-+ - addition
- - subtraction
* - multiplication
/ - real division ( = 2.5)
^ - power
DIV (\) - integer division (5 \ 2 = 2)
MOD - remainder division (5 MOD 2 = 1)