A Level Computer Science OCR H446

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A level (H446) Computer Science
1.1 Characteristics of contemporary processors, input, output and storage devices
1.1.1	Architecture	Main Parts of a CPU	Control Unit ALU Registers
		Registers within the CPU	Accumulator Memory Data Register Memory Address Register Program Counter Current Instruction Register
		Fetch-Decode-Execute Cycle	Registers involved Fetch, decode, execute cycle
		CPU performance factors	Clock speed Multi-core Cache RAM size GPU Pipelining
		System performance factors	Faster CPU Improved RAM Graphics card Upgraded Drive Upgraded OS
		Von Neumann and Harvard	Von Neumann architecture MAR & MDR Program Counter Accumulator Harvard architecture
1.1.2	Types of Processor	CISC and RISC	CISC RISC
1.1.2	Types of Processor	Multicore and Parallel processing	Pipelining Array processor Multi-core GPU
1.1.3	Input Output and Storage	Selecting Devices	Input Output Storage
		Type of storage	Magnetic Optical Solid State Backup and Archiving
		RAM and ROM and virtual storage	Main memory Volatile memory - what is it? RAM DRAM SRAM ROM Virtual storage

1.2 Types of software and software development
1.2.1	Operating System	Purpose of an operating system	Kernel Device Drivers Utilities User Interface
		Memory Management	Segmentation Pagination Virtual memory Memory issues
		Interrupts and Polling	Polling Interrupt CPU and interrupts
		Scheduling	Round Robin First Come First Serve Shortest Job Shortest time Multi-level
		Types of operating systems	Multi Tasking Multi User Distributed Real Time Embedded Batch
		BIOS	Booting BIOS POST System start Operating system boot
		Device Drivers	Kernel Device drivers User interface Utilities
		Virtual Machines	Virtual machines VM with operating system VM with bytecode
1.2.2	Applications Generation	Types of applications and utilities	Applications Utilities Generic software Bespoke & Custom software Closed source Open source
		Applications generation Program creation	Translators Interpreters Compilers Assemblers
		Stages of compilation	Lexical Syntactic Code generation
		Linkers Loaders & Libraries	Modules Libraries Linkers Loaders
1.2.3	Software development	Software Development	Waterfall Rapid Application Development Spiral Agile Extreme Programming Merits of different software methods
1.2.4	Types of programming language
		Programming Paradigms	Paradigms Low level languages Procedural languages Object Oriented languages Declarative languages Functional languages
		Procedural language techniques	What is a procedural language Procedures Subroutines Functions Program flow Variables and Scope Constants String Handling File Handling Operators
	Assembly language
		Little Man Computer (LMC)	LMC Model Instruction Set Labels Calculation Branching Input-Output Loops
		Memory Modes	Immediate addressing Direct addressing Indirect addressing Indexed addressing
1.2.5	Object Orientated Programming	OOP	Class Attributes Methods Objects Interface Encapsulation Polymorphism

1.3 Exchanging data
1.3.1	Compression & Encryption	Compression	Principle of compression Lossy compression Lossless compression Dictionary compression Run Length encoding Huffman encoding
		Encryption	Symmetric encryption Asymmetric encryption RSA and AES Comparison Public-private keys
		Hashing	What it is Hash uses Passwords Digital Certificates Faster searching
1.3.2	Databases	Databases	Flat file databases Relational databases Primary key Foreign key Secondary key
		Normalisation	First Normal Form Second Normal Form Third Normal Form
		SQL	SQL language Tables Create and Alter Select and retreive Combine with JOIN
		Transaction Processing	Transaction C.R.U.D A.C.I.D
1.3.3	Network Characteristics	Networks	Network Characteristics Protocol and standards importance
		Models and Protocol Layering	Internet 4 Layer Model Protocol Layering Physical & Logical layers OSI
		The TCP/IP stack	TCP/IP Ports and Sockets
		Internet Protocols	Global standards UDP HTTP(s) FTP POP,LDAP,SMTP Ethernet
		IP Addressing	IP Format Subnet Mask IANA and ICANN IPv4 and IPv6 DNS and Domain Name MAC address
		LANs, WANs, PANs, SANs, MANS	PAN LAN WAN SAN and MAN
		Packet & Circuit Switching	Circuit switching Datagrams Packet Switching
		Network configuration	Client Server Peer to peer
		Network Security	Authentication User rights User Education Encryption Firewall Proxy Server
		Network Hardware	NIC - Network Interface Controller Router Bridge Hub Switch WAP
1.3.4	Web Technologies	Web Technologies	HTML CSS Javascript
		Compression	Principle of compression Lossy compression Lossless compression
		Web Search	Web crawler spider Page Rank Advanced Search
		Client & Server processing	Client side processing Client side pros and cons Server side processing Server side pros and cons Processing technologies

1.4 Representing Data
1.4.1	Primitives	Primitive	Integer Real Character String Boolean
		Integer	Range Unsigned Signed Sign & Magnitude Two's compliment
		Real	Fixed point Floating point Mantissa, Exponent Placing binary point
		Normalising	Floating point limits Normalising Floating point Examples
		Arithmetic	Floating point addition Floating point subtraction
		Bit manipulation	Left shift Right shift Circular shift AND, OR, XOR applied
		Character Sets	Character Set ASCII Extended ASCII Unicode UTF-8
		Hexadecimal Numbers	Why Hexadecimal Denary to Hexadecimal Hexadecimal to Denary Binary to Hexadecimal Hexadecimal to Binary
1.4.2	Data Structures	Data Structures	List Linked List Array Tuple Dictionary (associative array)
		Arrays	1 dimensional array 2 dimensional array 3 dimensional array Array iterations Array operations
		Queue and Stack	Queue Stack LIFO queue FIFO queue Code examples
		Graph	Undirected graph Directed graph Weighted graph Adjacency Matrix Adjacency List Breadth First Search Depth First Search Python code examples
		Trees	Parts of a tree Tree traversal Preorder traversal Inorder traversal Postorder traversal Python tree code example
		Hash tables	Hashing Hash Functions Load Factor Search algorithm Linear Probe Chaining
1.4.3	Logic	Boolean Logic	Boolean algebra expressions Logic and design NOT operation OR operation AND operation XOR operation NAND operation NOR operation
		Gates, Expressions	Combining gates Multi-level diagrams Expression to Diagram Building Truth tables Diagram to Truth tables
		Karnaugh Maps	Constructing Minimise expression Truth table to minterms Minterms to Map
		Simplification	Boolean identities Boolean Laws De Morgan's Theorems Simplifying practice
		Adders	Half Adder Full Adders Cascading Overflow

1.5 Legal, moral, cultural and ethical issues
1.5.1	Computing related legislation
1.5.2	Ethical, moral and cultural issues	Artificial Intelligence
		Automated Decision Making
		Censorship and the internet
		Computers in the workforce

2.3 Algorithms, their use to describe problems and standard algorithms
2.3
	Algorithms	Algorithm analysis	Analysing algorithms Space efficiency Time efficiency Compromises Big O notation
		Big O expressions	Analysing algorithms Big O as functions Complexity Simplifying Inner loops Main term Comparing algorithms
		Search Sort algorithms	Linear Sequential search Binary search Bubble sort Insertion sort Merge sort Quicksort
		Path finding algorithms	Dikjstra's algorithm A* algorithm

A Level Computer Science OCR H446

A level (H446) Computer Science

1.1 Characteristics of contemporary processors, input, output and storage devices

1.2 Types of software and software development

1.3 Exchanging data

1.4 Representing Data

1.5 Legal, moral, cultural and ethical issues

2.3 Algorithms, their use to describe problems and standard algorithms