ICT Unit 1 Digital Devices

Mainframe computer

Is a computer with huge processing power and data storage

Microprocessor

The job of the microprocessor is to run the instructions of your computer program. 

Desktop computer

a computer designed to be in one place

Laptop computer

a computer designed to be portable

Pros of laptop

Portability,flexibility and multifunctional

Cons of laptop

Less powerful, short battery life and difficult to upgrade

Mobile phone

Ultra portable , designed to be light weight and fit in pockets

Specialist

designed for specific people

Tablet device

a general purpose device between laptop and smartphone

multifunctional device

a device that carries out a wide variety of tasks

Convergence

Is the merging of technologies that would usually be separate

Features of digital devices

Portability, performance, storage , user interface, connectivity, media support, energy consumption, expansion capability, security features

User interface

Is how the user interacts with the operating systen

Command line

Requires users to interact using text commands

Graphical user interface

Requires users to interact with the os using visual elements such as windows, icons, menus and WIMP

Menu interface

Successive menus presented to a user with a single option at each stage

Natural language

Uses spoken words to respond to spoken or textual inputs from a user

Flash memory

Is a type of electronically erasable programmable read only memory

Application software

Is the software chosen by the user to carry out a specific task for the user

System software

Is essential for the operating of a computer system

Utility software

designed to help maintain, enhance and repair a computer

Defragmentation

Groups of fragmented files back together to increase access speed

Task manager

built in OS allows users to monitor system resources

Operating system

Software that provides an interface between the user and the hardware in a computer system

Single user

Allows single user, no option to customize user interface

Security

Process enabling different users to log onto a computer

Print spooling

carried out by the os when printing is required . This creates a queue

secondary storage

it is non volatile, meaning it will keep data if there is no power. this may be external or internal

storage methods

magentic, optical and solid state

how a flash memory works

Large electric current used to force electrons through a barrier and trap them on the other side .They remain on the other side until ‘flashed’ with a new current, eg usb sticks and cameras

What is RAM

the part of the computer that temporarily stores the instructions that the computer is running, and the data it is processing. RAM is a volatile storage device as it loses data if the power is turned off

ROM

contains the BIOS (Basic Input Output System) . stores data permanently held in the primary storage it is non volatile as the data is not lost when the power is off. eg stores BIOS and initial program the computer runs

digital cameras and camcorders

use light sensors to capture images formed by light passing through the device lens. The quality depends on the lens eg capturing memories and advertising

navigation aids

calculate the best route between two locations

multi tasking

processors appear to be running in parallel but they are just being swapped in and out of RAM very quickly

backup

creates a copy of files and programs

compression

reduces the size of files

software updates

updates are done to fix bugs and add to new features etc

software licenses

the set of rules that tell you how can use a specific piece of software eg open source and closed source

magnetic storage

makes use of a magnetisable coating. Magnetised dots are made on the surface of the material.

optical storage

makes use of a laser to shine and reflect light to read the data stored eg, CD and DVDs used to store songs and videos

solid state drives SSD

use non volatile flash memory to store information used in higher end computers and laptops

processors

is made up of one or more central processing units (CPUs), they carry out software instructions . Each CPU is referred to as a core.

clock speed

describes the time per second the processor can carry out one or more instructions

proprietary software

software that is paid for. source code not provided

free/open source

software that is free to use and can be changed by the user

network OS

allows multiple accounts to be set up against username and passwords

input peripherals

webcam,tablet and mouse

output peripherals

speaker,projector ,printer

accessibility

some peripherals add accessibility to the computer eg headset with microphone