Computer Misuse Act 1990

The law was enacted to: Illegalize unofficial access to computer systems Dissuade dangerous criminals from using a computer to commit a crime like impairment of access to data saved in the computer. The CMA is comprehensive and all-encompassing which has brought concerns among privacy supporters who believe in defining government impact on daily life and …

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Testing and Test Data

Purposes of Testing To enable objective assessments regarding the degree of conformance of the system to the stated requirements and specifications. To verify that the system meets the different requirements. To validate that the system is what the user needs. To improve the quality of product. Example of Testing in Software Development Product objectives are …

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Biometrics

Biometrics comes from the words bio and metric.  Bio means life while metric means to measure. The biometric system links an event to one individual, while other ID forms, like the personal identification number (PIN), may be used by anyone. Types of Biometrics Physiological identifiers – associated with the structure of the user is confirmed …

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Control Systems

A control system is a group of mechanical or electronic devices that uses control loops to control other devices or systems.  Control systems are automated with the use of computers. It is a vital part of the automation industry.  Some types of control loops are as follows: ICS – Industrial Control Systems SCADA – Supervisory …

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Types of Memory

Candidates should be able to: describe the difference between RAM and ROM explain the need for ROM in a computer system describe the purpose of RAM in a computer system explain how the amount of RAM in a personal computer affects the performance of the computer explain the need for virtual memory describe cache memory …

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The Central Processing Unit (CPU)

Candidates should be able to: state the purpose of the CPU describe the function of the CPU as fetching and executing instructions stored in memory explain how common characteristics of CPUs such as clock speed, cache size and number of cores affect their performance. What is the purpose and function of the CPU? The purpose …

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Computer Instructions

Candidates should be able to: explain how instructions are coded as bit patterns explain how the computer distinguishes between instructions and data. How are program instructions coded? Machine code instructions are binary numbers and are coded as bit patterns, for example, a 16 bit machine code instruction could be coded as 001010101101001011. In machine code …

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Character Sets

Candidates should be able to: explain the use of binary codes to represent characters explain the term character set describe with examples (for example ASCII and Unicode) the relationship between the number of bits per character in a character set and the number of characters which can be represented. How are binary codes used to …

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Number Systems

Candidates should be able to: convert positive denary whole numbers (0-255) into 8-bit binary numbers and vice versa add two 8-bit binary integers and explain overflow errors which may occur convert positive denary whole numbers (0-255) into 2-digit hexadecimal numbers and vice versa convert between binary and hexadecimal equivalents of the same number explain the …

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DBMS

Candidates should be able to: describe how a DBMS allows the separation of data from applications and why this is desirable describe the principal features of a DBMS and how they can be used to create customised data handling applications. What is a DBMS? A Database Management System (DBMS) is used to manage a database. …

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Sound Representation

Candidates should be able to: explain how sound can be sampled and stored in digital form explain how sampling intervals and other considerations affect the size of a sound file and the quality of its playback. How can sound be sampled and stored in digital form? A microphone converts sound waves into voltage changes. If …

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Image Representation

Candidates should be able to: explain the representation of an image as a series of pixels represented in binary explain the need for metadata to be included in the file such as height, width and colour depth discuss the effect of colour depth and resolution on the size of an image file. How can an …

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Data Units

Candidates should be able to: define the terms bit, nibble, byte, kilobyte, megabyte, gigabyte, terabyte understand that data needs to be converted into a binary format to be processed by a computer. Data units in computer systems Bit This is a single unit of memory and can only store 2 possible binary values, either 0 …

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Software and Operating Systems

Candidates should be able to: explain the need for the following functions of an operating system: user interface memory management peripheral management multi-tasking security describe the purpose and use of common utility programs for: computer security (antivirus, spyware protection and firewalls) disk organisation (formatting, file transfer, and defragmentation) system maintenance (system information and diagnosis, system …

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Computer Networks

Candidates should be able to: explain the advantages of networking stand-alone computers into a local area network describe the hardware needed to connect stand-alone computers into a local area network, including hub/switches, wireless access points explain the different roles of computers in a client-server and a peer-to-peer network describe, using diagrams or otherwise, the ring, …

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Data Structures and Algorithms

Candidates should be able to: define the terms variable and constant as used in an imperative language use variables and constants describe the data types integer, real, Boolean, character and string select and justify appropriate data types for a given program perform common operations on numeric and Boolean data use one-dimensional arrays. What are constants …

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Testing Your Code

Candidates should be able to: describe syntax errors and logic errors which may occur while developing a program understand and identify syntax and logic errors select and justify test data for a program, stating the expected outcome of each test. What are syntax errors? Syntax errors are errors that occur when instructions do not follow …

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LMC Addition and Subtraction

The following program will demonstrate the ADD and SUB instructions of the LMC instruction set. Instructions Copy the ten line program above and paste it into the Program box. Click on the “Assemble Program” button. After the program is assembled you should see RAM addresses 0 to 8 contain the machine code instructions shown in …

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LMC Input and Output

The following program will demonstrate the INPUT and OUTPUT instructions of the LMC. Running the program: the program simply INPUTS a number, then OUTPUTS it. Instructions Copy the three-line program above and paste it into the Program box. Click on the “Assemble Program” button. After the program is assembled you should see RAM addresses 0 …

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LMC Load and Save

The following program will demonstrate the use of LDA and STA, the Load and Save instructions used in the . Running the program: when prompted, INPUT a set of two numbers. The program should then OUTPUT them in the same order that they were entered. INP STA first INP STA second LDA first OUT LDA …

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Little Man Computer

A Little Man Computer (LMC) is a simulator which has many of the basic features of a modern computer that uses the Von Neumann architecture.