IGCSE comp sci topic 4

human computer interface (HCI)

human computer interface (HCI)

- an interface supplied by the operating system to 'hide' the complexities of the software and hardware from the human user

service (an interrupt)

- when an interrupt is received, some action needs to be taken by the processor depending on what caused the interrupt; until this is resolved (that is, it is serviced), the interrupt cannot be removed to allow the processor to continue

utility programs (utilities)

- part of an operating system which carries out specific functions such as virus checking, defragmentation and screensaver.

Malware

- programs (such as viruses, worms and Trojan horses) that are installed on a user's computer with the aim of deleting, corrupting or manipulating data illegally

anti-virus software

- software that quarantines and deletes files or programs infected by a computer virus; the software can run in the background or be initiated by the user

Heuristic checking

- checking software for behaviour that could indicate a possible virus

quarantine

- to isolate (in order to later delete) a file or program identified by anti-virus software as being infected by a virus

Defragmentation

- a process that reorganises sectors on an HDD by rearranging blocks of data so that they are contiguous

Contiguous

next to each other

back up

- make copies of files onto another storage media in case the original file becomes corrupted or is deleted

screensaver

- software that supplies a still or moving image on a monitor if a computer has been inactive for a period of time

device driver

- software that communicates with the operating system and translates data into a format understood by the device

descriptor

- a collection of information about a device plugged into a USB port; this can be vendor ID (VID), product ID (PID] or serial number

operating system

- software that provides an environment in which applications can run and also provides an interface between computer and human operator

boot up/bootstrap loader

a small program that is used to load other programs to correctly 'start-up' a computer system

EEPROM

- stands for electronically erasable programmable ROM

command line interface (CLI)

- an interface which allows communication with the computer by typing in commands using a keyboard

graphical user interface (GUI)

A visual display on a computer's screen that allows you to interact with your computer more easily by clicking graphical elements with a mouse or touch screen

windows icons menu and pointing device (WIMP)

- an interface that uses a pointing device such as a mouse to select options from screen icons or a menu

Post-WIMP

- a modern touch screen interface system that allows actions such as pinching and rotating

memory management

- the part of an operating system that controls main memory

Security Management

- the part of an operating system that ensures the integrity, confidentiality and availability of data

Hardware Management

- the part of an operating system that controls all input and output devices; it is made up of sub-systems such as printer management

Buffer

- a memory area used to store data temporarily

File Management

- part of an operating system that manages files in a computer (for example, the ability to create, delete, copy, open, close and rename files)

interrupt

- a signal sent from a device or software to a microprocessor requesting its attention; the microprocessor suspends all operations until the interrupt has been serviced

Multitasking

- a function that allows a computer to process more than one task/process at a time

administrator

- a person responsible for the upkeep and maintenance of a computer system that involves multi-user function

user account

- an agreement that allows an individual to use a computer; the user needs a user name and password to enter the user's area

error handling routine

- a routine in a program or operating system that recognises and recovers a system from abnormal inputs or hardware faults (for example, recovery from an attempt to divide by zero)

Firmware

- a program that provides low level control for devices

Interrupt priority

- the priority assigned to an interrupt are given a priority so that the microprocessor knows which one needs to be serviced first and which interrupts are to be dealt with quickly

Interrupt Service Routine (ISR)

- software that handles interrupt requests (for example, when the printer out of paper) and sends a request to the CPU for processing

Machine Code

- a binary programming language, a program written in machine code can be loaded and executed without translation

High-Level Language (HLL)

- a programming language that is independent of computer hardware, a program written in a HLL needs to be translated into machine code before it is executed.

Low-Level language (LLL)

- a programming language that is dependent on computer hardware, both machine code and assembly language are LLLs

Assembly Language

- a programming language that is dependent on computer hardware, a program written in an assembly language program needs to be translated into machine code before it is executed

Assembler

- a computer program that translates programming code written in assembly language into machine code

Compiler

- a computer program that translates a source program written in a high-level language to machine code

Translator

- converts a program written in a high-level language program into machine code

interpreter

- a computer program that analyses and executes a program written in a high-level language line by line

Integrated Development Environment (IDE)

- a suite of programs used to write and test a computer program written in a high- level language

Debugging

- finding errors in a computer program by running or tracing the program

Prettyprinting

- displaying source code using different colours and formatting, which make the code easier to read and understand

Report window

- a separate window in the runtime environment of an IDE that shows the contents of variables during the execution of a program