The programs that run on the hardware Essay Example for Free

The programs that run on the hardware Essay Presentation software The main use of this software is to animated visual presentations. Examples of use include:   presentations for meetings   computer-based help systems Graphics software There are two types of graphics packages. Bitmap graphics software stores images as lots of coloured dots, known as pixels. Vector based graphics software stores images as rules, covering the dimensions, direction, and colour of the drawn object. Function Explanation/description drawing tools pre-defined shapes ability to scale, stretch, and crop images ability to rotate images ability to flip images paint palettezoom/magnify ability to fill Computer aided design (CAD) software The main use of this software is to design three dimensional objects. HTML editing software The main use of this software is to create web-pages. Communications software There are two types of communications software. Electronic mail, used to send and receive messages. Web-browser software to view web pages on the Internet. Integrated software A software package that combines the functions of two or more distinct generic applications. Specific software Software designed to carry out a single task for users. System software Software that manages and controls the computer and all its peripherals. Operating system software A layer of software that enables a user to control the hardware, and application programs to run on the computer. Utility software Software used to carry out routine tasks often needed by the user to maintain the performance of the computer. Hardware Hardware is the name given to any part of the computer that you can actually touch. A device is an individual piece of hardware. Examples include:   keyboard   visual display unit (VDU) or monitor   floppy disk drive Describing hardware Technical specification. This is a list of its properties. It usually refers to the performance and/or capacity of the device. Performance This is a way of describing how well a device in a computer system does its job. This often refers to the speed at which it works. Capacity This is the amount of data that can be stored. Processor The central processing unit (CPU) is the part of the computer where the searching and sorting of data, calculating and decision-making goes on. Also known as the processor. Choosing a processor Processors are measured by their speed. The number of instructions it can perform in 1 second. This is measured in hertz (Hz). 1 hertz = 1 instruction per second 1 KHz = 1,000 instructions per sec 1 MHz = 1,000,000 instructions per sec 1 GHz = 1,000,000,000 instructions per sec Input devices Input devices are used to enter commands or information into a computer. Examples of input devices include:   keyboard   mouse   scanner   microphone   trackball   joystick/ joypad   graphics tablet digital camera/ web-camera Output devices Output devices are used by the computer to communicate information to human users or to affect a change in a physical environment. Examples of output devices include: VDU/monitor   printer   speakers Types of VDUs/monitors cathode ray tube (CRT) liquid crystal display (LCD) less expensive to buy more expensive to buy better quality image lower quality image can be easily viewed from an angle can only be properly viewed from one angle requires more power requires less power gives off lots of heat gives off less heat takes up a lot of space takes up less space more likely to cause eye strain less likely to cause eye strain Choosing VDUs/monitors Type cathode ray tube (CRT) or liquid crystal display (LCD) (thin-film transistor [TFT]) Colour. Monochrome, or grey-scale, or colour Resolution measured in pixels; 640 X 480 (VGA), 800 X 600 (SVGA), 1024 X 768 (XVGA or XGA) Size diagonal distance, from one corner to another (inches) Types of printers inkjet laser less expensive to buy more expensive to buy more expensive to run less expensive to run relatively slow speed printing relatively fast speed printing Choosing printers Speed characters per second (cps) or pages per minute (ppm) Quality dots per inch (dpi) Colour monochrome, or colour Data storage devices Storage devices are used to store the programs and data needed by the computer. The two main categories of storage devices are main memory and backing storage. Main memory RAM random access memory RAM is used by the computer to store the programs and data that are being used at a given time. RAM is volatile which means that when the computer is turned off all its contents are wiped clean. Choosing RAM RAM is measured by its capacity; the amount of data that it can store when the computer is switched on. All computers ultimately store data as 1s and 0s (this number system is known as binary). A single unit (either 1 or 0) is called a bit. 8 bits = 1 byte 1,000 bytes = 1 KB 1,000 KB = 1 MB 1,000 MB = 1 GB Backing storage Backing storage is used to store programs and data when they are not being used or when the computer is switched off. Backing storage is non-volatile which means that when the computer is turned off none of its contents are lost. backing storage device used to read and write data onto storage media. backing storage media the collective name given to the disks and tapes used to store data. Choosing backing storage The first decision is between fixed media or removable media. Backing storage media can be measured by its capacity; bytes, or kilobytes (KB), or megabytes (MB), or gigabytes (GB). Backing storage can also be judged by the data transfer speed of the backing storage device to the backing storage media. This is measured in; bytes per second (Bps), or kilobytes per second (KBps), megabytes per second (MBps). Audio CDs read at 150KBps 8X, 16X, 24X, 48X, 52X. The final way that backing storage can be differentiated is whether it is: * read only memory (ROM), or * recordable (R)/ write once read many (WORM), or * read and write (RW). Types of portable backing storage * floppy disk drive (FDD) * compact disk (CD) drive * Zip drive * digital versatile disk (DVD) drive * flash stick Computers and peripherals Desktop computer An entire computer that sits on a desk or a table. Laptop computer A personal computer that can be simply carried around by one person and used in transit from internal battery power. Peripherals Standard (expected) Additional (extra) hard disk drive (HDD) printer floppy disk drive (FDD) scanner VDU/monitor microphone keyboard web-cam mouse (pointing device) joystick CD drive (ROM/R/RW) DVD drive (ROM/R/RW) speakers Zip drive Social Impact In the home In business P:\ICT\KS4\Yr09\Yr09Revision. 0304. doc HBDugard Page 1 of 10 Last printed 28/05/2004 14:09