A- Level Computer Science Q&A Guide

1 Dimensional Arrays A standard list array - one index is needed to search for something in an array. 2 Dimensional Arrays An array with 2 indexes needed to search - for example a table could be this. Interception of PseudoCode The ability to pick out and explain parts of code. Big O' A meas...

Abstraction Representation that is arrived at by removing unnecessary details Pop Remove and return the last item from a list/data structure Push To add an item to the top of a stack/end of a queue/list Depth First Traversal Each node in one branch is visited before backtracking to explore the ...

CPU Central Processing Unit ALU Arithmetic Logic Unit CU Control Unit PC (CPU) Program Counter ACC Accumulator MAR Memory Address Register MDR Memory Data Register

CPU Central Processing Unit ALU Arithmetic Logic Unit CU Control Unit PC (CPU) Program Counter ACC Accumulator MAR Memory Address Register MDR Memory Data Register

176 Convert Denary 374 to Hexadecimal. 2DF Convert Denary 735 to Hexadecimal. Convert Hexadecimal DB7 to Binary. 64001 Convert Hexadecimal FA01 to Decimal. The binary number obtained by subtracting each digit in a binary number from 1. Define one's compliment. The one's compliment of a bin...

A Network of Networks. Internet A process or set of rules to be followed to solve a given problem. Algorithm A collection of related records. File A collection of related fields. Record Is an Internet standard for electronic mail transmission. SMTP Is an Internet standard protocol used by e-mai...

Baud Rate The maximum possible number of signal changes that can occur in a wire per second. Bit Rate The number of bits that can be sent down a wire per second. Integer A whole number that can be positive, negative or zero. Examples: -3, 0, 7, 2013588. Natural (Number) A whole number that is ...

What is an integer? A positive or negative whole number What is a Real or Float number? A positive or negative number that can have a fractional part. What is a Boolean? True or False What is a character? A single letter, number or symbol What is a string? A group of characters What is Date/T...

Software Software comprises all of the programs that make the computer function Hardware The physical components of a computer system Systems software Required to run and manage the computer's hardware and application programs Disk Defragmentation Process of consolidating fragmented files on t...

What is a static IP Address - never changes - provided by ISP What is the purpose and benefits of networking devices - File sharing - you can easily share data between different users. - Resource sharing - using peripheral devices and software between users, saves money - Sharing a single in...

Protocol A set of rules governing the exchange or transmission of data between devices. Hypertext Transfer Protocol (HTTP) protocol that defines how messages are formatted and transmitted over the World Wide Web File Transfer Protocol (FTP) a simple network protocol that allows the transfer of...

Constants They are variable whose values will not be changed by the program. What are the advantages of having constants? - Improves the readability of code - Easier to update the programming code if the value changes - Reduce the likelihood of inconsistency causing errors if multiple places use ...

Abstraction a way of separating logical and physical parts of a problem e.g. the london underground map. You get rid of unnecessary details Problem abstraction where you keep removing details until the problem reduces to one that has already been solved Modelling and Simulation Building a mode...

Start LDA one OUT LDA zero OUT LDA count SUB one STA count BRP start HLT One DAT 1 Zero DAT 0 Count DAT 3 Explain, giving an example, how pipelining in a CPU could speed up the execution of this program. ( 3 marks ) An instruction can be fetched as the previous one is being decoded a...