Paper 1 - Computer Science

Paper 1 - Computer Science

1. 1.1 Computer Architecture

   • Key Vocab
     • Hardware: The physical parts or components of a computer
     • Peripheral: A peripheral device is any auxiliary device such as a computer mouse or keyboard that connects to and works with the computer in some way.
     • Input Peripheral: A device that may be connected to a computer system. They are used to bring data from the physical world into the computer system.EG Mouse, touchscreen.
     • Output Peripheral: A device that may be connected to a computer system. They are used to bring data from the computer into the physical world. EG A monitor or speakers.
     • Storage Peripheral: A device which is used to store data & files on. EG CD, Memory stick.
   • Hardware
     • BIOS: Basic Input Output System. A small program is stored on this ROM chip to load the operating system correctly.
     • CMOS Battery: Small battery used to keep track of the time when a computer is switched off
     • CPU: Central Processing Unit. The device used to control and execute commands within the computer. The performance is measured in GHz, which is the number of processes which can be executed in 1 second.
     • GPU: Graphics Processing Unit. Used for processing of graphics, particularly used by gamers and graphic designers.
     • Motherboard: The motherboard connects all components to each other, which allows them to communicate
     • Hard Drive: Area of storage used to retain documents and programs. A form of long term memory. Alternatives may include SSD or hybrid drives.
     • PCI: An expansion port that allows a computers capabilities to be upgraded. Components that may be upgraded include GPU, sound cards and NICs.
     • RAM: Random Access Memory, a place where data and instructions that are currently in use by the CPU or have recently been used are stored.
     • PSU: Power Supply Unit. Converts mains AC to low‐voltage DC power to power all components of a computer.

2. 1.2 Memory

   • Key Vocab
     • Primary Memory: Memory used to store data and instructions that are required by the CPU.
     • RAM: Random Access Memory is volatile memory used to store data and instructions which are needed by the CPU. Also referred to as main memory.
     • Static RAM: Uses 5 transistors which are wired together to represent each bit. No need to be refreshed. More wiring per bit.
     • Dynamic RAM: Contains 1 transistor and capacitor that hold charge briefly. This needs to be refreshed every few milliseconds.
     • ROM: Read only memory. Used to store the boot sequence as this should never be changed. This memory is non‐ volatile.
     • Bootstrap Loader: A small program that loads the operating system. Once the operating system is loaded it takes care of the rest.
     • Flash Memory: Electrons are forced into a layer between two barriers which hold the charge by using a high electric current.
     • Virtual Memory: When RAM is full, a section of the hard drive can be used to store programs and instructions.
     • Volatile: Storage which needs to have power to store data. If power is lost, data is lost.
     • Non-Volatile: Storage which does not lose its contents when the power is lost.
   • RAM VS ROM
     • RAM
     • ROM

3. 1.3 Storage

4. 1.4 Wired & Wireless Network

5. 1.5 Network Topology

6. 1.6 System Security

7. 1.7 System Software

8. 1.8 Ethical, Legal, Cultural & Environmental Issues