OCR
A Level Computer
Science
A full summarized guide
Connor
6-6-2023
, 1
CONTENTS
1.1 The characteristics of contempary processors ................................................................................................. 4
1.1.1 Structure and Function of the processor ................................................................................................... 4
Computer Architecture ................................................................................................................................... 4
Fetch Decode Execute Cycle ........................................................................................................................... 4
Factors affecting CPU performance: ............................................................................................................... 4
1.1.2 Types of processors ................................................................................................................................... 5
CISC ................................................................................................................................................................. 5
RISC ................................................................................................................................................................. 5
GPU ................................................................................................................................................................. 5
1.1.3 Input, Output and Storage ......................................................................................................................... 6
Optical Drives .................................................................................................................................................. 6
Magnetic ......................................................................................................................................................... 6
Flash ................................................................................................................................................................ 6
RAM & ROM ................................................................................................................................................... 6
Virtual storage ................................................................................................................................................ 7
1.2 Software and software development ............................................................................................................... 8
1.2.1 Systems software ....................................................................................................................................... 8
Types of operating systems ............................................................................................................................ 8
Memory Management .................................................................................................................................... 8
Interupts ......................................................................................................................................................... 8
Scheduling ...................................................................................................................................................... 9
Device drivers ............................................................................................................................................... 10
1.2.2 Applications generation ........................................................................................................................... 11
Stages of compilation ................................................................................................................................... 11
Linkers ........................................................................................................................................................... 11
Loaders ......................................................................................................................................................... 11
Translators .................................................................................................................................................... 11
Libraries ........................................................................................................................................................ 12
Nature of applications .................................................................................................................................. 12
Open-Source vs Closed-Source ..................................................................................................................... 12
1.2.3 Software Development ............................................................................................................................ 13
Programming Methodologies ....................................................................................................................... 13
Writing and following algorithms ................................................................................................................. 13
, 2
1.2.4 Types of Programming language ............................................................................................................ 14
Procedural language ..................................................................................................................................... 14
Assembly language ....................................................................................................................................... 14
Modes of adressing memory ........................................................................................................................ 14
Object oriented languages............................................................................................................................ 14
1.3 Exchanging Data ............................................................................................................................................. 16
1.3.1 Compression, encryption and hashing .................................................................................................... 16
Compression ................................................................................................................................................. 16
Encryption..................................................................................................................................................... 16
Hashing ......................................................................................................................................................... 16
1.3.2 Databases ................................................................................................................................................ 16
Regional database ........................................................................................................................................ 16
Structured query language ........................................................................................................................... 17
Handling data................................................................................................................................................ 17
Normalisation ............................................................................................................................................... 18
1.3.3 Networks.................................................................................................................................................. 19
Networks and Protocols ............................................................................................................................... 19
The internet structure .................................................................................................................................. 20
DNS ............................................................................................................................................................... 20
Protocols ....................................................................................................................................................... 20
Client server .................................................................................................................................................. 20
Peer-to-peer networks: ................................................................................................................................ 21
Packet and circuit switching ......................................................................................................................... 21
Network security and threats ....................................................................................................................... 22
Network hardware........................................................................................................................................ 22
1.3.4 Web technologies .................................................................................................................................... 23
JavaScript ...................................................................................................................................................... 23
Lossy vs Lossless ........................................................................................................................................... 23
CSS ................................................................................................................................................................ 23
HTML............................................................................................................................................................. 23
Search engine indexing ................................................................................................................................. 24
Server-side processing .................................................................................................................................. 25
Client-side processing ................................................................................................................................... 25
1.4 Datatypes, structures, and algorithms ........................................................................................................... 26
1.4.1 Datatypes ................................................................................................................................................. 26
, 3
Binary ............................................................................................................................................................ 26
Bitwise manipulation and masks .................................................................................................................. 26
Character sets ............................................................................................................................................... 26
1.4.2 Data structures ........................................................................................................................................ 26
Hash tables ................................................................................................................................................... 26
Trees ............................................................................................................................................................. 27
Stacks ............................................................................................................................................................ 27
Queues .......................................................................................................................................................... 27
Arrays, tuples and lists .................................................................................................................................. 27
Graphs .......................................................................................................................................................... 27
1.4.3 Boolean algebra ....................................................................................................................................... 28
Logic circuits ................................................................................................................................................. 28
Karnaugh Maps ............................................................................................................................................. 28
1.5 Legal, moral and ethical issues ....................................................................................................................... 28
1.5.1 Computing related legislation.................................................................................................................. 28
The data protection act 1998 ....................................................................................................................... 28
The computer misuse act 1990 .................................................................................................................... 29
The copyright, design and patents act 1988 ................................................................................................. 29
The regulation of investigatory powers act 2000 ......................................................................................... 29
1.5.2 moral and ethical issues .......................................................................................................................... 29
Computers in the workforce ......................................................................................................................... 29
Automated decision making ......................................................................................................................... 29
Artificial intelligence ..................................................................................................................................... 30
Environmental Effects................................................................................................................................... 30
Censorship and the internet ......................................................................................................................... 30
Monitor Behaviour ....................................................................................................................................... 30
Analyse Personal Information ...................................................................................................................... 30
Privary and offensive communications ........................................................................................................ 31
Layout, Colour Paradigms and Character sets .............................................................................................. 31
A Level Computer
Science
A full summarized guide
Connor
6-6-2023
, 1
CONTENTS
1.1 The characteristics of contempary processors ................................................................................................. 4
1.1.1 Structure and Function of the processor ................................................................................................... 4
Computer Architecture ................................................................................................................................... 4
Fetch Decode Execute Cycle ........................................................................................................................... 4
Factors affecting CPU performance: ............................................................................................................... 4
1.1.2 Types of processors ................................................................................................................................... 5
CISC ................................................................................................................................................................. 5
RISC ................................................................................................................................................................. 5
GPU ................................................................................................................................................................. 5
1.1.3 Input, Output and Storage ......................................................................................................................... 6
Optical Drives .................................................................................................................................................. 6
Magnetic ......................................................................................................................................................... 6
Flash ................................................................................................................................................................ 6
RAM & ROM ................................................................................................................................................... 6
Virtual storage ................................................................................................................................................ 7
1.2 Software and software development ............................................................................................................... 8
1.2.1 Systems software ....................................................................................................................................... 8
Types of operating systems ............................................................................................................................ 8
Memory Management .................................................................................................................................... 8
Interupts ......................................................................................................................................................... 8
Scheduling ...................................................................................................................................................... 9
Device drivers ............................................................................................................................................... 10
1.2.2 Applications generation ........................................................................................................................... 11
Stages of compilation ................................................................................................................................... 11
Linkers ........................................................................................................................................................... 11
Loaders ......................................................................................................................................................... 11
Translators .................................................................................................................................................... 11
Libraries ........................................................................................................................................................ 12
Nature of applications .................................................................................................................................. 12
Open-Source vs Closed-Source ..................................................................................................................... 12
1.2.3 Software Development ............................................................................................................................ 13
Programming Methodologies ....................................................................................................................... 13
Writing and following algorithms ................................................................................................................. 13
, 2
1.2.4 Types of Programming language ............................................................................................................ 14
Procedural language ..................................................................................................................................... 14
Assembly language ....................................................................................................................................... 14
Modes of adressing memory ........................................................................................................................ 14
Object oriented languages............................................................................................................................ 14
1.3 Exchanging Data ............................................................................................................................................. 16
1.3.1 Compression, encryption and hashing .................................................................................................... 16
Compression ................................................................................................................................................. 16
Encryption..................................................................................................................................................... 16
Hashing ......................................................................................................................................................... 16
1.3.2 Databases ................................................................................................................................................ 16
Regional database ........................................................................................................................................ 16
Structured query language ........................................................................................................................... 17
Handling data................................................................................................................................................ 17
Normalisation ............................................................................................................................................... 18
1.3.3 Networks.................................................................................................................................................. 19
Networks and Protocols ............................................................................................................................... 19
The internet structure .................................................................................................................................. 20
DNS ............................................................................................................................................................... 20
Protocols ....................................................................................................................................................... 20
Client server .................................................................................................................................................. 20
Peer-to-peer networks: ................................................................................................................................ 21
Packet and circuit switching ......................................................................................................................... 21
Network security and threats ....................................................................................................................... 22
Network hardware........................................................................................................................................ 22
1.3.4 Web technologies .................................................................................................................................... 23
JavaScript ...................................................................................................................................................... 23
Lossy vs Lossless ........................................................................................................................................... 23
CSS ................................................................................................................................................................ 23
HTML............................................................................................................................................................. 23
Search engine indexing ................................................................................................................................. 24
Server-side processing .................................................................................................................................. 25
Client-side processing ................................................................................................................................... 25
1.4 Datatypes, structures, and algorithms ........................................................................................................... 26
1.4.1 Datatypes ................................................................................................................................................. 26
, 3
Binary ............................................................................................................................................................ 26
Bitwise manipulation and masks .................................................................................................................. 26
Character sets ............................................................................................................................................... 26
1.4.2 Data structures ........................................................................................................................................ 26
Hash tables ................................................................................................................................................... 26
Trees ............................................................................................................................................................. 27
Stacks ............................................................................................................................................................ 27
Queues .......................................................................................................................................................... 27
Arrays, tuples and lists .................................................................................................................................. 27
Graphs .......................................................................................................................................................... 27
1.4.3 Boolean algebra ....................................................................................................................................... 28
Logic circuits ................................................................................................................................................. 28
Karnaugh Maps ............................................................................................................................................. 28
1.5 Legal, moral and ethical issues ....................................................................................................................... 28
1.5.1 Computing related legislation.................................................................................................................. 28
The data protection act 1998 ....................................................................................................................... 28
The computer misuse act 1990 .................................................................................................................... 29
The copyright, design and patents act 1988 ................................................................................................. 29
The regulation of investigatory powers act 2000 ......................................................................................... 29
1.5.2 moral and ethical issues .......................................................................................................................... 29
Computers in the workforce ......................................................................................................................... 29
Automated decision making ......................................................................................................................... 29
Artificial intelligence ..................................................................................................................................... 30
Environmental Effects................................................................................................................................... 30
Censorship and the internet ......................................................................................................................... 30
Monitor Behaviour ....................................................................................................................................... 30
Analyse Personal Information ...................................................................................................................... 30
Privary and offensive communications ........................................................................................................ 31
Layout, Colour Paradigms and Character sets .............................................................................................. 31
