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1

Give two reasons why a programmer would choose to write code in a low-level language. High-level languages require either an interpreter or a compiler to translate the program. The table below lists a number of statements about language translators. Tick (3) to show which statements refer to interpreters and which refer to compilers. Statements Interpreter (3) Compiler (3) Translates the source code into machine code all at once Produces an executable file in machine code Executes a high-level language program one instruction at a time Once translated, the translator does not need to be present for the program to run An executable file is produced

4. Software  →  4.2. Types of programming language, translators and integrated development environments (IDEs)

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2

State four functions of an operating system.

4. Software  →  4.1. Types of software and interrupts

3. Hardware  →  3.1. Computer architecture

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3

Explain what is meant by: Serial data transmission Parallel data transmission A computer in a factory is connected to a printer. The printer is located in an office 1 km away from the factory. Identify which data transmission method would be most suitable for this connection. Give two reasons for your choice.

2. Data transmission  →  2.1. Types and methods of data transmission

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4

Nine bytes of data are transmitted from one computer to another. Even parity is used. An additional parity byte is also sent. The ten bytes arrive at the destination computer as follows: parity bit bit 2 bit 3 bit 4 bit 5 bit 6 bit 7 bit 8 byte 1 byte 2 byte 3 byte 4 byte 5 byte 6 byte 7 byte 8 byte 9 parity byte One of the bits was corrupted during the data transmission. Circle the corrupt bit in the corrupt byte in the table above. Explain how the corrupted bit was found.

2. Data transmission  →  2.2. Methods of error detection

1. Data representation  →  1.1. Number systems

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5

A computer uses an 8-bit register. The 8-bit register contains binary integers. Write the denary (base 10) value represented by: All the bits in the register are shifted one place to the right as shown below. Write the denary number that is represented after this shift. State the effect the shift to the right had on the original denary number from part . The original number in part is shifted three places to the right. Show the new binary number: Write the equivalent denary number. Describe the problems that could be caused if the original binary number in part is shifted five places to the right.

1. Data representation  →  1.1. Number systems

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6

Four computer terms and eight descriptions are shown below. Draw lines to connect each computer term to the correct description. Computer term Description Arithmetic and logic unit (ALU) Control unit Random access memory (RAM) Read only memory (ROM) Data can be read but not altered Carries out operations such as addition and multiplication Stores bootstrap loader and BIOS Fetches each instruction in turn Carries out operations such as AND, OR, NOT Stores part of the operating system currently in use Stores data currently in use Manages execution of each instruction

3. Hardware  →  3.1. Computer architecture

3. Hardware  →  3.3. Data storage

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7

Complete the truth tables and name the single logic gate that could replace each logic circuit: A B X A B Working space X Single logic gate A B X A B Working space X Single logic gate Draw a logic circuit to represent the following logic statement: X = 1 if (A = 1 AND B = 1) OR ( (B = NOT 1) AND C = 1) A B C X Complete the truth table for the logic statement in part . A B C Working space X

10. Boolean logic  →  10. Boolean logic

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8

Identify whether the four statements about file compression are correct by writing TRUE or FALSE in the following table. Statement TRUE or FALSE MIDI files store the actual music notes in a compressed format JPEG files are examples of lossless file compression MP3 files are, on average, 90% smaller than the music files stored on a CD MP4 files are examples of lossy file compression

1. Data representation  →  1.3. Data storage and compression

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9

Explain what is meant by a denial of service attack. Name and describe two other potential security threats when using the Internet. Security threat 1 Description Security threat 2 Description

5. The internet and its uses  →  5.3. Cyber security

3. Hardware  →  3.4. Network hardware

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10

Describe what is meant by HTML. The following URL is typed in: http://www.cie.org.uk/ComputerSciencePapers This URL is composed of three parts. State the part of this URL that is the: File name Protocol Web server name

5. The internet and its uses  →  5.1. The internet and the world wide web

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11

A security system is installed in a house. A hexadecimal number is entered to activate or deactivate the alarm. The alarm code is set to hexadecimal number 2 A F Show how this number would be stored in a 12-bit binary register. Identify two sensors that the security system could use to detect intruders. Describe how each sensor could be used in the security system. Sensor 1 Description Sensor 2 Description

1. Data representation  →  1.1. Number systems

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12

Explain the differences between freeware and free software.

4. Software  →  4.1. Types of software and interrupts

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