AQA A-Level Computer Science Paper 2 Last Minute Revision

Flashcards for AQA A-Level Computer Science Paper 2 revision, covering Fundamentals of Data Representation, Computer Systems, Programming Languages, Logic Gates, Boolean Algebra, Computer Organization and Architecture, Uses of Computing, Communication and Networking, Databases, Big Data and Functional Programming.

What are Natural Numbers?

The set of all positive integers including zero (0, 1, 2, 3, …).

What are Integer Numbers?

All positive and negative whole numbers including zero (…, -3, -2, -1, 0, 1, 2, 3, …).

What are Rational Numbers?

Numbers that can be expressed as fractions where the denominator is not zero.

What are Irrational Numbers?

Numbers that cannot be expressed as fractions, and their decimal expansions are non-repeating and non-terminating (e.g., √2, π).

What are Real Numbers?

Include all rational and irrational numbers, covering all possible values on the continuous number line.

What are Ordinal Numbers?

Used to indicate the position or order of elements in a sequence.

What are Number Bases?

Systems of numeration such as decimal (base 10), binary (base 2), and hexadecimal (base 16).

What is a Bit?

The smallest unit of data in computing, representing a binary digit (0 or 1).

What is a Byte?

A group of 8 bits, used as the standard unit of data storage and transmission in computers.

What are Kibi (Ki), Mebi (Mi), Gibi (Gi), Tebi (Ti)?

Prefixes representing powers of 2 (2^10, 2^20, 2^30, 2^40 respectively).

What do Decimal Prefixes represent?

Powers of 10 (10^3, 10^6, 10^9, 10^12 respectively).

What are Unsigned Binary numbers?

Binary numbers without a sign bit, used to represent non-negative integers.

What is Signed Binary using Two’s Complement?

A method for representing both positive and negative integers in binary.

What is Floating Point Representation?

Mantissa and exponent representation used to represent fractional numbers and large numbers with reduced precision.

What is ASCII?

American Standard Code for Information Interchange, using 7 or 8 bits to represent characters.

What is Unicode?

Universal character encoding standard, supporting most of the world's writing systems.

What are Parity Bits?

Adding an extra bit to data to ensure even or odd parity for error detection.

What are Checksums?

Summing data bytes to detect errors based on the sum's remainder.

What are Check Digits?

A digit appended to a number to check its accuracy (e.g., in credit card numbers).

What are Bitmapped Graphics?

Pixel-based representation with each pixel represented by bits.

What are Vector Graphics?

Uses mathematical equations to define shapes rather than pixels.

What is Digital Audio?

Sound represented as a sequence of samples.

What is Encryption?

Secure transformation of data into an unreadable format, requiring a key to decrypt.

What is Hardware?

Physical components of a computer system, including the CPU, memory (RAM), storage devices, and I/O devices.

What is Software?

Programs and data that run on the computer, including system software and application software.

What is System Software?

Manages and controls the hardware and provides a platform for running application software. It includes operating systems, utility programs, and device drivers.

What is Application Software?

Serves specific user needs, allowing users to accomplish tasks such as creating documents, browsing the web, playing games, etc.

What is the function of Operating Systems (OS)?

Manage computer hardware and software resources, provide services for computer programs, and establish a user interface.

What is the function of Utility Programs?

Perform maintenance tasks, manage system resources, and provide diagnostic information.

What are Libraries?

Collections of precompiled routines or functions that application software can use to perform specific tasks.

What are Translators?

Convert high-level programming languages into machine code that can be executed by a computer's CPU.

What is Hardware Abstraction?

Presents a simplified interface to the hardware, hiding its complex details from application software.

What is Resource Management?

Allocates system resources such as CPU time, memory, and I/O devices to processes.

What is a User Interface?

Provides a means for users to interact with the computer through graphical user interfaces (GUIs) or command-line interfaces (CLIs).

What is Machine Code?

Binary instructions directly executed by the computer's CPU.

What is Assembly Language?

Mnemonic representations of machine code instructions.

What are Imperative High-Level Languages?

Specify sequences of operations that the computer should perform.

What does an Assembler do?

Translates assembly language code into machine code.

What does a Compiler do?

Translates entire high-level source code into machine code before execution.

What does an Interpreter do?

Executes high-level code directly by translating and executing it line-by-line.

What is Bytecode?

Intermediate representation used by some compilers (e.g., Java).

What does a NOT Gate do?

Inverts the input (0 becomes 1, and 1 becomes 0).

What does an AND Gate do?

Outputs 1 only if all inputs are 1.

What does an OR Gate do?

Outputs 1 if at least one input is 1.

What does an XOR Gate do?

Outputs 1 if inputs are different.

What does a NAND Gate do?

Outputs 0 if all inputs are 1.

What does a NOR Gate do?

Outputs 0 if at least one input is 1.

What are Truth Tables?

Shows all possible input-output combinations for a gate.

What are Circuit Diagrams?

Visual representations of logic gates and their connections.

What are Boolean Expressions?

Mathematical representations of logic circuits using AND, OR, NOT operations.

What are Identity Laws?

A + 0 = A, A ⋅ 1 = A

What are Domination Laws?

A + 1 = 1, A ⋅ 0 = 0

What are Complement Laws?

A + A = 1, A ⋅ A = 0

What are De Morgan’s Laws?

A ⋅ B = A + B, A + B = A ⋅ B

What is the Role of the Processor (CPU)?

Executes instructions from programs, performing basic arithmetic, logical, control, and input/output operations specified by the instructions.

What does the Arithmetic Logic Unit (ALU) do?

Performs arithmetic and logical operations.

What does the Control Unit (CU) do?

Directs operations of the CPU, managing the fetch-execute cycle.

What is the Role of Main Memory (RAM)?

Temporarily stores data and instructions that the CPU needs while performing tasks.

What is the Role of the Address Bus?

Carries memory addresses from the CPU to other components like RAM and I/O devices.

What is the Role of the Data Bus?

Transfers actual data between the CPU, memory, and other peripherals.

What is the Role of the Control Bus?

Carries control signals from the CPU to other components to manage operations like read/write.

What is the Role of I/O Controllers?

Manage data exchanges between the CPU and peripheral devices (e.g., keyboard, mouse, printers).

What is Von Neumann Architecture?

Uses a single memory for both instructions and data.

What is Harvard Architecture?

Uses separate memory and buses for instructions and data.

What is Addressable Memory?

Each memory location in RAM has a unique address.

What is the Stored Program Concept?

Machine code instructions are stored in main memory, and the processor fetches and executes these instructions sequentially.

What is the role of Arithmetic Logic Unit (ALU)?

Performs arithmetic (addition, subtraction) and logical (AND, OR, NOT) operations.

What is the role of Control Unit (CU)?

Directs the operation of the processor by telling the ALU, memory, and I/O devices how to respond to program instructions.

What is the role of Clock?

Synchronizes the operation of all parts of the CPU and controls the timing of all operations.

What is the role of General-Purpose Registers?

Temporary storage areas for data and instructions currently being used by the CPU.

What does Program Counter (PC) hold?

Holds the address of the next instruction to be executed.

What does Current Instruction Register (CIR) hold?

Holds the current instruction being executed.

What does Memory Address Register (MAR) hold?

Holds the memory address of the data to be fetched or stored.

What does Memory Buffer Register (MBR) hold?

Holds the data that is being transferred to or from memory.

What does Status Register hold?

Holds flags that indicate the status of the CPU, such as carry, zero, sign, and overflow.

What is Immediate Addressing?

The operand is the actual data.

What is Direct Addressing?

The operand is the address of the data in memory.

What does Load do?

Load data from memory into a register.

What does Add do?

Add the value of two registers or a register and a value.

What does Subtract do?

Subtract the value of two registers or a register and a value.

What does Store do?

Store data from a register into memory.

What is Conditional Branching?

Branch to a specific address if a condition is met.

What is Unconditional Branching?

Branch to a specific address regardless of conditions.

What does Halt do?

Stop the execution of instructions.

What is the Role of Interrupts?

Temporarily halt the current CPU processes to service an external event or high-priority task.

What is the effect of Multiple Cores on Processor Performance?

Increases parallel processing capability, improving performance for multi-threaded applications.

What is the effect of Cache Memory on Processor Performance?

Provides faster access to frequently used data, reducing the time the CPU spends waiting for data from the main memory.

What is the effect of Clock Speed on Processor Performance?

Higher clock speeds result in more instructions being executed per second, improving performance.

What is the effect of Word Length on Processor Performance?

Larger word lengths allow the CPU to process more data per instruction, improving performance.

What is the effect of Address Bus Width on Processor Performance?

Wider address buses can address more memory locations, enabling larger memory capacity.

What is the effect of Data Bus Width on Processor Performance?

Wider data buses can transfer more data per cycle, improving data transfer rates and overall performance.

What is the Purpose of a Barcode Reader?

Scans barcodes to input data.

What is the Purpose of a Digital Camera?

Captures and digitizes images.

What is the Purpose of a Laser Printer?

Produces high-quality printed output.

What is the Purpose of RFID (Radio Frequency Identification)?

Uses radio waves to read and capture information stored on a tag.

What is the Purpose of Secondary Storage?

Provides non-volatile storage for data and programs, ensuring data is retained even when the computer is turned off.

What is the Purpose and Principle of Hard Disk Drive (HDD)?

Provides long-term storage of large amounts of data; uses magnetic storage to record data on rotating disks (platters).

What are Optical Disks?

CDs, DVDs, Blu-rays; used for storage and distribution of data and uses laser technology to read and write data

What is the Purpose and Principle of Solid-State Drive (SSD)?

Provides fast, reliable storage for operating systems and applications; uses NAND flash memory and a controller to manage data storage.

What is Serial Transmission?

Data is sent one bit at a time over a single channel.