Computers- Software and Hardware

This section discusses the various components of a personal computer (PC) and the devices that are typically used with it, such as printers. Here are the available options for selecting these components, as well as their advantages.

 

Summary:   

Hardware  

Keyboard 

Monitor 

System module

Processor 

Memory

Hard disk

Floppy disk drive 

CD-ROM drive 

Peripheral devices

Types of personal computers

 

  Hardware

Your computer consists of hardware and software. The term hardware encompasses the physical, real components of a computer. These parts can be seen and touched. On the other hand, software (or programs) consists of coded expressions that instruct the computer how to perform the necessary tasks. For example, the CD that you insert into the CD-ROM drive of your PC is hardware. The programs in it are generally called software. Software is an important part of a computer - without software it is nothing more than a pile of electronic components. 

The topic of software deserves a whole separate chapter. That is why Chapter 2 discusses this matter in detail. In this chapter, we look at PC hardware. 

The personal computer consists of the following main hardware components:

 

 Keyboard

 

 The keyboard is an input device that you need to give instructions to your computer. The standard keyboard layout for writing in English is called QWERTY, as these are the first six keys in the top row. There are two types of key layout for writing in Cyrillic: phonetic (the letters of the keys correspond to the Latin ones from the standard QWERTY layout) and BDS (the keyboard layout is the same as with a regular typewriter). However, the computer keyboard also contains some additional keys: 

 Enter When entering keyboard commands, you must press the Enter key. Only in this way can the computer perceive what you have written. This key is also used to mark the end of a paragraph. 

Control (labeled Ctrl) and Alternative (Alt) These keys are used in combination with each other or with other keys for special purposes, largely dependent on the software. For example, pressing the Ctrl, Alt, and Delete keys simultaneously restarts the computer (or, in computer terminology, "reboot"). 

Function keys These keys are labeled F1, F2, F3 and so on up to F12. They are used by various software products to instruct the computer to perform certain tasks. For example, the F1 key typically provides access to help information provided by your software. 

Escape (designated Esc) This key is also mainly controlled by the software. It is usually used to exit a specific screen, dialog box or option selected by a software application. 

PageUp, PageDown, Insert and Delete These keys are commonly used in a word processor. They allow you to move page by page within a long document (PageUp and PageDown - one screen page up and down) or edit text (Insert and Delete - insert and delete). 

Arrow keys These keys are located near the numeric keypad (located on the right). Each of them is marked with an arrow pointing in one of the four directions. You can use them to move the cursor - this is usually a vertical bar used for positioning within text blocks in various software applications. 

Print Screen Copies an image from the screen to the Windows system clipboard.

 

 Monitor

 Monitors are also called screens or displays. They look just like portable TVs. In fact, earlier computers did not come with monitors. TV screens were used instead. This is a cheaper alternative, but the image quality is poor compared to the specially designed monitors you can buy today as part of your computer. 

The monitor of the PC is controlled by a graphics card (also called a video card) - a printed circuit board placed in the system box of the computer before the monitor is installed. The graphics card converts computer data into monitor-friendly signals. To do this, the monitor and the graphics card must be compatible with each other.

 

 System module

 The system module is the main component of your PC. It is a plastic or metal box containing several important elements that make a computer what it is.  

The main components in the system box are: Processor Memory, Hard disk, Floppy disk drive, CD-ROM drive

 

 Processor 

 The processor is often considered the "brain of the computer." This is due to the fact that all the dirty work is done in it. The processor (also called CPU - Central Processing Unit, central processor) obeys software instructions and manipulates the relevant data. It has full control over all other components, such as memory, hard drive and printer. 

The processor is an integrated circuit and resembles the processors found in washing machines, microwaves and televisions. Most PCs produced today use high-speed processors from the Intel Pentium family. Intel's main competitors are AMD and Cyrix.

 

 Memory 

 Computer memory stores information needed by the processor. This information may represent the data to be processed or the programs used to process the data. From the outside, memory is simply a collection of integrated circuits (chips). In fact, what matters is exactly what the chips contain. There are two types of memory - Read Only Memory (or ROM) and Random Access Memory (RAM).

 

 Hard disk

 Hard disks are able to store much more data, and the processor can access hard disk data much faster than floppy disk data. Therefore, the PC can run much faster. 

While some of the early computers used floppy disks as the main storage medium, today all modern computers have hard disks (along with a floppy disk drive). The storage capacity of modern hard drives rarely falls below a few gigabytes (GB for short) and reaches several tens of gigabytes. One megabyte holds just over 1 million characters, and one gigabyte equals 1,000 megabytes. Thus, a hard disk with a capacity of 1GB can hold more than a thousand million characters.

 

 Floppy disk drive 

 The floppy disk drive, which looks like a crack in the front panel of the system box, is used to read and write floppy disks. In the past, PC floppy disks had a disk diameter of 5¼ inches or 3½ inches. Every new PC today has a 3-inch floppy disk drive. These diskettes have a larger capacity and are better protected by a hard plastic cover. You can have more than one floppy disk drive in your system, although one hard drive and one floppy are sufficient for most applications.

 

 CD-ROM drive 

The CDs used in computers are completely identical to music CDs. The only difference between them is the type of information recorded on them (if you insert a computer CD into your audio CD player, you will only hear buzzing and whistling). Unlike the hard disk and the floppy disk drive, which store and read information on an electromagnetic basis, CDs operate on an optical basis. The surface of the CD is covered with millions of protrusions and dents through which the stored data is encoded. To read the contents of a CD, a laser beam is aimed at its surface. The quality of the light reflected on the receptor is used to determine whether the beam has hit a protrusion or a recess, and as the disk rotates under the laser beam, the encoded data is read and decoded. 

Peripheral devices

 So far we have looked at the main components of a personal computer. Some of the peripherals added to the PC to increase its usefulness and ease of operation are: Mouse, Printer, Scanner, Modem, A sound card, CD-R drive, Archiving device, Joystick, Graphic tablet, Plotter.

 

Mouse

Although the mouse is an optional input device for connecting to a computer, its presence is vital for working with modern Windows-based software. 

The mouse is placed on the desk, usually on a pad next to the keyboard. To move its pointer on the screen, simply move the mouse up, down, left or right and when you reach the desired place on the screen, press the left Ј button. Some software features are available by right-clicking, which displays a context menu depending on where you clicked on the screen (also called a context-sensitive menu). 

 The Microsoft mouse is one of the most user-friendly. It has an improved shape for more comfortable placement of the hand on it. The Microsoft Intellimouse model is even better - this mouse has a small wheel between the left and right buttons. You can rotate this wheel to scroll through the information displayed in a window, or to zoom in or out on a document preview.

 

 Types of personal computers

  Are you confused by the wide variety of PCs on the market? You will probably find it helpful to accept that they are just very sophisticated and expensive calculators and they are all designed to perform the same functions. PC models differ in speed, capacity and portability. Obviously, a faster machine is more expensive. If you are going to use the computer for serious high-end applications, you will need a PC with a large storage capacity. If you have to use your computer in different places, you will probably need to buy a lightweight portable PC (laptop, notebook). The microprocessor is the main part of the personal computer that determines its capabilities. When you look at the specification of a PC, you will notice the MHz designation described as part of the processor type, such as the Pentium 200MHz. This is an estimate of the actual speed of the chip. MHz stands for Megahertz and 1MHz equals one million pulses per second. Therefore, 200MHz is equal to 200 million pulses per second. The computer has an internal clock that delivers millions of cycles per second. Each instruction executed by the PC uses several cycles, but the higher the number of cycles per second, the faster the computer will execute the instruction. For this reason, the Pentium 200MHz is faster than the Pentium 166MHz.

 Here's what the classification of computers on the market today looks like in general: 

 Desktop - designed to be placed on a desk where they are expected to sit most of the time. 

 Portable (notebook, laptop) - their idea is to satisfy mobile users who travel often and need an easily portable PC. 

 Handhelds - even smaller, pocket-sized computers, but you need to use special compact versions of the software you need.