GCSE ICT – Imput devices - Sample Essay
The library has six tapes, one for each day of the week that the library is open, Monday to Saturday. They back up the server so that they have a copy of the data they collected that day, in case they were to have a problem with the server all the would have to do is install the Magnetic tape on the server again. If the library did not back up copies every night and they were to have a problem with the computers that meant that all the data was lost, they would have to restart from the last place saved and this would mean that they lose every thing that was taken out or returned after the last back up tape was copied.
If they have a back up copy from the evening before the only information lost would be from after the copy was made. Output devices Monitor Monitor is just another name for the screen. The CRT monitor creates a picture out of many rows or lines of tiny colour dots. The more lines of dots per inch, the higher and clearer the resolution. The benefit of a TFT monitor is a separate, tiny transistor for each pixel on the display. Because each transistor is so small, the amount of charge needed to control it is also small. The image is refreshed several times per second.
The library has monitors similar to the ones in the above picture on the right which is a TFT monitors. The library has large screens so that the screens are easily seen by all users. Many people with poor eye sight find it easier to see a large screen, so the library larger screens to accommodate there needs. The library has tried to make the computers useable by every one so the people do not feel discriminated against. The TFT monitors do not take up a lot of desk space. They produce less radiation than the old CRT type.
They give off a bright, steady image which does not cause eye strain. The TFT monitors that the library has are part of a standard Dell package. TFT monitors are very difficult to read if you are not looking directly at them. This means that computer users have more privacy because other people in the library will not be able to read their screens. Printer There are three main types of printer are laser, Dot- Matrix or Inkjet printers. The laser printer is very expensive to buy but cheap to run. The output in a laser printer is very high quality, and it prints very fast.
Dot- Matrix printers are very old, very slow, and very noisy. They also have a poor output quality, however there’s cheap to buy and fairly reliable. Inkjet printers are cheap to buy. The quality of print is high, and they are quite fast printers. However, the printer inks are very expensive and if the print out gets wet, it can smear. The library uses laser printers because they are cheap to run. The library has two printer a coloured printer and a black and white printer The printers are located at the issue desk.
Staff regulate prints through the issue desk computer using the pc counter software, members have to pay the staff for the prints (15p for black and white and 50p colour) then staff allow the prints to be printed. This save paper and money as before people would print lots of pages and they would only want one of the pages. Members would only pay for the one they wanted. Staff would use the printers to print out notices, flyers, posters and letters. Computer speakers Computer speakers are use to play sounds from the computer. They range widely in quality and in price. The computer speakers are usually small plastic boxes.
Some of the slightly better computer speakers have equalization features, improving their sound quality. The library computers do not have speakers; they like to keep the library quiet so that people can concentrate with out distractions. Members my use head phones to listen to sound as these are quiet and can only be heard by the person wearing them Head phones can be purchased at the issued desk for around i?? 2 or members can use there own. Processors The processor is a part of a computer which carries out calculations and does all of the processing that has to be done.
The processor is often called the CPU. The speed of the processor is measured in MHz and the larger the number the faster and more powerful the processor is. A processor must be cooled by a fan other wise it will over heat. Modern processors are either dual or quad which makes them very fast. The libraries computers use a Pentium IV 2. 4 GHZ processor. This is a fast processor which allows users to have multimedia programs running and allows multi tasking. They are very suitable for general computer use. Ports and Cables Universal Serial Bus Nearly every computer comes with Universal Serial Bus or USB.
USB is a standard connection port for many devices such as Memory pens, keyboards, mice, joysticks and digital cameras. Before USB, connecting devices to your system was often a hassle. Modems and digital cameras were connected via the serial port which was quite slow. In the library the computers have two USB ports to the front and two to the back. USB ports are easy to connect to, they are faster and smaller. Users can plug a range of device in to USB ports such as cameras, air darts, MP3 players, external optical drives, mice, keyboards, memory pens and much more. Serial Port The serial port has been used on computers for years.
Many of the newer systems have done away with the serial port completely in favour of USB connections; most modems still use the serial port, as do some printers and digital cameras. Few computers have more than two serial ports. Computer mice and even keyboards were used on serial ports. In the library USB ports have taken the place of Serial ports. All thought the computers in the library still have Serial ports they are considered to be older technology and are rarely used or needed in the library. They do however come as a standard part of the Dell computer which the library has purchased. Parallel port.
The parallel port is still commonly used for printers however USB is becoming more popular. A PC sends data to a printer or other device using a parallel port. The standard parallel port is capable of sending 50 to 100 kilobytes of data per second. Parallel ports are not used on the library computers as most devices are now connected using the faster USB connection. These ports come as standard on the computers which the library has bought. Ethernet port An Ethernet port is used to connect a computer to a network. In the library all computers are connected to the network using a CAT5-e cable with a RJ-45 connector.
These are at the back of the computer and the members are not allowed to remove them. Fibre optic cable Fibre optic cables are made from two types of glass. Fibre optic cables are thinker than a human hair and are very flexible. These cables carry information using pulses of light. Fiber optic cables are very fast. The library uses optic fibres to connect their servers to the internet, the speed is very fast and there is no interference. Fibre optic cables are very expensive, but they give an excellent internet connection which in fast and reliable.