Computers

Posted on March  4th, 2010 by Technology Department 

In this topic we're going to study the fundamental parts of computers and what functions they havecomputer

In general terms, the function of computers is to take in data that is inputted by peripherals (keyboard, mouse, stylus etc), process this data using a programme (software) and send it to the exterior again using another peripheral (printer, monitor, storage disk etc.)


Types of Computer

 

  • How many types of computer do you know?

    The use of computers is so widespread that many different types of computer have appeared. Some are easy to transport, some aren't.

    Desktop computer. This is the most used type of computer in offices. It's big and heavy. It's the cheapest but it consumes lots of energy.

    Laptop computer. Because lots of people want these computers, production costs have gone down and they are more commonly used in the home. They use less energy but they are a bit more expensive.
    Media Center. You can watch tv, see photos, connect to the internet etc.

    PDA (personal digital assistant). It's possible uses are limited by its size. It is commonly used when mobility and space are important.
     

Computers: Parts

 

Computers: Parts

Computers are composed of two important parts: hardware and software.

Hardware is the electronic or physical parts of the computer. That is, it is the parts you can touch. Examples are:
The motherboard that contains the microprocessor, the RAM, the sound card etc.
The power supply whose job is to supply the correct amount of current and tension to the different parts of the computer.
The hard disk, where the programmes are stored.
The entry and exit peripherals like the mouse and keyboard
The exit peripherals like the monitor.
Others, like the router, are used to both receive and send data by internet.

Motherboard

In the picture we can see a PC motherboard. The following elements are important to mention.
1. The processor support where the processor which does the most important jobs in the computer is housed.
 

Motherboardmicroprocessor

In the  right, you can see a microprocessor from a computer.

It undertakes the mathematical and logical functions of the programmes, as well as other functions.
Depending of the speed and on the number of integrated transistors the microprocessor is more or less powerful. That is, it can do more jobs in less time.
This part works so hard that it needs a heatsink next to its own fan.

 

 

RAM (Random Access Memory)

Is the memory which uses semiconductors and can be read and written on by microprocessors and other hardware devices.
The memory chips are small black rectangles that are usually soldered in groups to plaques with pins or contacts. The difference between RAM and other types of storage memory, like disks or hard disks, is that RAM is much faster and is erased when the computer is turned off.
 

The chipset

 It is  an electronic component whose job is to manage data transfers between the electronic components of the computer such as the processor or the memory.

The BIOSBios

Short for Basic Input - Output System  is the first programme to work when the computer is turned on.
It uses data to find out what the system's hardware configuration is.
The BIOS is stored in ROM ( short for read-only memory ).

 

Connectors

 motherboards connectors

Most motherboards have the following connectors

  • A parallel port, mainly for connecting old printers
  • A serial port. It was used for connecting old periphericals
  • USB ports, for connecting more recent peripherals
  • RJ45 connector used for connecting the computer to a network.
  • VGA connector for connecting a monitor.
  • Line-In, Line-Out and microphone, for connecting sound speakers or a microphone. These connectors are included in the sound card.
     

Peripherals

 

peripherals

A driver is a file that tells the operating system how data should be exchanged between the peripherals and the computer.

Drivers are different for every peripheral and every operating system. A driver for a digital camera in Windows won't work in Linux.
Nowadays it is very easy to connect a peripheral to a computer because computer systems recognise them easily (plug and play) and if it needs you to incorporate the driver, it will tell you using a menu.
On the right you can see some webcams, used for video conferences.

The monitor

The monitor is a peripheral that shows all the information in visual form; for example, a letter, photo or film.
The most important characteristics of the monitor are:
The resolution:
This is the number of dots that the monitor can represent on the screen, in horizontal x vertical. Therefore, a monitor whose maximum resolution is 1024x768 points can represent up to 768 lines horizontally each with 1024 dots. It can probably also produce inferior resolutions like 640x480 u 800x600.
The greater the resolution of a monitor, the better the quality of the image and the greater the quality (and price) of the monitor. The resolution should be appropriate to the size of the monitor; it's normal for a 14” or 15” not to offer 1280x1024 dots, but that is the minimum you expect from a 17” or bigger monitor.  

The monitor: Scren Refresh

You can compare it to the number of frames per second in a film, so it should be as high as possible. It is measured in Hz (Hertz) and should be more than 60Hz and preferably 70 or 80 Hz. From this number upwards the image on the screen is very stable, it doesn't blink and it doesn't affect our vision as negatively. If the refresh is very slow, we would see the images in bits.

It is the graphics card that provides these refreshes but it is the monitor that presents them. If we use a screen refresh that the monitor can't support we can damage the computer, so we need to know our computer's capacity very well and we should read the manual very carefully. Dot pitch
 

Dot pitch (size of dots)
 

This parameter measures the sharpness of the image, measuring the distance between two points in the same colour. It is fundamental when the resolution is high. Sometimes it is differently horizontally to how it is vertically or sometimes it is an average value, depending on the particular placing of the dots of colour on the screen and on the type of grid used to direct the electron beams.
The minimum we want is 0.28mm, and it shouldn't be higher except in large format monitors for presentations where the size of the image is more important than the resolution.
 

The graphics card

graphic  video card

This is what transmits to the monitor the graphic information which should appear on screen. To do this it performs two operations:

* It interprets the data that comes in from the processor, it orders them and calculates how to present them on the screen in the form of a quite large rectangle made up of individual dots of different colours (pixels).

* It takes the digital data resulting from the above operation and transforms it into an analog signal that the monitor can understand.
These two processes are normally performed by one or more chips: the graphic microprocessor (the brain of the graphics card) and the analog-digital converter or RAMDAC. Sometimes there are other accessory chips for other functions or sometimes there is only one chip that performs every function.
The microprocessor can be very powerful or advanced, sometimes even more advanced and powerful than the computers own microprocessor

Posted on 20010