SOME BASIC ESSENTIALS FOR COMPUTERS

              There is no better place to begin, than the beginning

This chapter is designed to accomplish two things:

1. Provide a basic understanding of how to work with a personal computer.

2. Serve .is guidelines for materials to include in personal computer training programs.

The information in this chapter assumes no prior knowledge of or experience with a personal computer. Anyone who has a comfortable working relationship with a personal computer may wish to skim over this section to get ideas of how to structure an introductory training course. For others starting from scratch, however, the chapter will focus on building a working knowledge of:

The keyboard

The operating system

Working with diskettes

Security and backups

GETTING STARTED

As noted earlier, the two most common types of personal computers that will be encountered in most organizations are machines containing two diskette drives, and those with one diskette drive and a hard disk.

Diskette drives refer to the number of slots on the microprocessor for inserting diskettes. Two-drive systems have one slot for the program diskette and one for working on and storing the results (see Figure 30).

Since hard disks offer the storage equivalent of 30 diskettes, they require only one diskette drive for entering information (see Figure 31), although they may be configured with two drives for more sophisticated applications. In either case, the loading process is the same. The diskette drive(s) has an opening through which diskettes are inserted into the computer. Each opening has a device similar to a door that can be opened and closed using what is called a lift load lever. Once a diskette is inserted, the door is closed behind it by pushing the load lever down. While the system reads your program, a small red light on the front of your disk drive will come on. Do not open the drive door while this light is on. Doing so may permanently damage the program, and under some circumstances the system unit itself.

 

 

 

 

FIGURE 31. Proper way of loading a diskette. Courtesy of International Business Machines.

To make things more comfortable, it is possible to make minor adjustments to the height of the keyboard and the brightness and contrast of the display monitor. If the display monitor is near a source of bright light, such as a window, or has a high degree of glare, an anti glare screen might be appropriate.

Depending on the model, most keyboards have two to three possible positions. These range from, flat to a five-degree to 15 degree angle. To adjust the height, pick up the keyboard and, make the  necessary adjustment using the knobs at each end.

Brightness and contrast can be adjusted using the control knobs generally found on the front of the monitor. On systems that share multiple users, this will probably have to be done every time a person sits down to work. Everything a computer does is governed by operating sys tern, which is a software program that manages many of the computer’s basic functions. It acts as an intermediary between hardware and software and performs such tasks as controlling the input output devices, assigning spaces in memory to programs and data, and controlling how the system processes information. -

For IBM and IBM-compatible machines the operating system is called DOS (Disk Operating System), MS-DOS, or PC-DOS. They all perform the same basic functions.

The operating system must be present whenever a system is on in order for anything to be accomplished. In addition, it must be copied to all software before that software can be installed or used. Most software is generic in nature and written to be run on more than one brand of machine. Copying the operating system onto a software program allows it to become compatible with a particular system. Instructions accompany most software programs.

Booting is the process of actually loading DOS into a system. Booting clears the memory, loads the operating system, and gets the computer ready to process its work. If this is done when a machine is first turned on, it is called a cold boot. If the operating system is loaded after a system is already up and running, it is called a warm boot.

To perform a cold boot, simply put a copy of DOS or its equivalent in Drive A, and turn the computer on. The on—off switch that controls the system unit or microprocessor is located at the rear of the unit. On IBM machines, the switch will always be on the right-hand side (see Figure 32).

This is the recommended way to activate an entire system:

First, turn on the printer

Second, turn on the monitor

Third, turn on the CPU

Follow this sequence because one of the first things a system unit does is to check what is connected to it, and whether or not they are working properly. Turning the system on as described

 

 

FIGURE 32. Locations of on/off switch on IBM system unit. Courtesy of International Business Machines.

is the most effective way to accomplish this. If a unit is connected to multisocket electrical power strip or surge suppressors check to see that it is turned on as well. Many people control the power to all their system components through such devices, using them to turn everything on simultaneously.

When the power is switched on, the first sound heard will be the motor humming as the computer checks to see how much memory it has  take from 3 to 90 seconds, depending on how much memory has been installed. Memory will be counted in units   which can be seen blinking by at the top left—hand corner of a monitor.

When the memory check is completed, the computer will emit a short beep, and then display the following message:

Current date is 01-01-1980

Enter new date:

At this point, a person may simply hit the “enter” key, or may provide the current date. If he or she is working with file materials, or materials that may require future reference, a date should be entered. To enter a date, the computer must be given the month, 1-12, day, 1-31, and year, 80-99. A correct entry might be: 10-14-1986.

The operating system will then ask for the time. Again, the choice is to simply hit “enter,” or supply the current time. Since a 24-hour clock is used, any time past noon should carry one of the following values:

1:00 = 1300 hr

2:00 = 1400 hr

7:00 = 1900 hr

8:00 = 2000 hr

3:00 = 1500 hr 9:00 = 2100 hr

4:00 1600 hr

5:00 1700 hr

6:00 = 1800 hr

10:00 = 2200 hr

11:00 = 2300 hr

12:00 = 2400 hr

The time is expressed in hours: minutes: seconds: and hundredths. Colons (:) must be used between• hours, minutes, and seconds. Any value that is omitted will be assumed to be a zero. For example, if it is 2:30 in the afternoon, you would enter 14:30 hrs. And the system would record 14:30:00.

To perform a warm boot, the system must be restarted by using the “Cntrl,”“Alt,” and “Del” keys simultaneously. The operating system disk should be in drive A, unless the system has a hard disk on which it has already been installed. As in a cold boot, the operating system will again ask to have the date and time entered.

 

Before we finish : If you need more help or have an opinion or suggestion Please leave a comment Below. This is a Do-Follow Blog leaving a comment will also help your blogs Google rank.

 

HOW A COMPUTER OPERATES

What goes on inside a computer is a mystery to most people, and even a little frightening to some. Actually, it is a fairly simple process - Whether we are talking about a supercomputer or one that can sit on top of a desk, all function in the same general way.

To understand how computers operate, we first have to break them down into several basic elements:

1. Input

2. Central processing unit (CPU)

3. Memory or storage

4. Output

Information is put into the computer through any of several different sources:

1. Keyboard

2. Data diskette (which can contain the program of instructions

What Are The Components Of A Personal Computer

The hardware components (those things you can see and touch), for a personal computer include:

A microprocessor (or system unit)—This is the Central Processing Unit (CPU) for a personal computer. While it looks like a box, it contains the memory systems (RAM and ROM) and is really the heart of the system. This unit also contains the disk drives. Since the memory is wiped clean each time you turn the machine off, you need a more permanent storage system. This is provided by keeping separate memory diskettes.

• A keyboard that lets you communicate with the system.

• A video display monitor (like a TV screen) that lets the system communicate with you.

• A printer that can produce a paper copy of whatever you are working on.

Diskettes—The software containing the programs you wish to run or on which to plan your work. A diskette is a small magnetic record that contains the storage space for your memory. When a diskette is inserted into a disk drive, it is spun much like a record on a turntable, and “read” electronically. A single sided diskette can hold the same amount of information as 110 pages of single-spaced text.

You will be working with, or the information you will be working on)

1. Cassette tape

2. Graphic tablets and electronic pens

3. Light pens, which can be used by directly touching the screen of a monitor

One key point to remember is that a computer will do exactly as it is told, and only what it is told. This can lead to what programmers call GIGO or Garbage In, Garbage Out. If the user doesn’t give the computer the correct information to work with, and precise’ instructions on what to do with that information, he or she will get back incorrect or meaningless answers and results.

Data is entered into the CPU. The CPU is where all the logical and control functions of a computer are carried out. The CPU is actually divided into two areas: a control unit, and the arithmetic and logic unit (ALU). The control unit spends its time figuring out what the computer is supposed to do next, and the ALU actually does it.

Memory is where information and instructions are stored. How does a computer memorize? A series of on/off switches lead an electrical current to a particular location, or address. Information is moved between the CPU and its memory banks by electronic pathways or conduits, called registers.

 

Before we finish : If you need more help or have an opinion or suggestion Please leave a comment Below. This is a Do-Follow Blog leaving a comment will also help your blogs Google rank.

WHAT IS A COMPUTER?

Thanks to Madison Avenue, Hollywood, and a horde of science fiction writers, some people have come to believe that computers have minds of their own and are capable of thinking for themselves. While there is some interest and developmental research in the field of artificial intelligence (the so-called fifth generation of computers, which would be able to learn from experience and improve their own performance on any given task), computers. We know them today are basically stupid.

This is an important point to remember, particularly when dealing with someone who has a fear of computers. Essentially, a computer can be thought of as a very fast, very large calculator that can manipulate or process a lot of information, under its own control. It will execute any command it is given with precision and speed, but won’t go beyond that point. In short, it will do exactly what it is told, and no more. It has no way of telling 4vliether the information it is working on is good or bad, unless it receives further instructions and is given some basis for comparison. The intelligence and control belong entirely to the person who is working with it. Turn it off and its memory can be wiped clean. It is important to think about computers as one of many tools (such as telephone, calculators, and electric typewriters and pencil sharpeners) that people have at their disposal to help make life a little easier. Like a calculator, a computer can add and subtract quickly and with a high degree of accuracy. When a person uses a calculator, however, a button has to be pushed for each function to be performed. A computer has the capacity to store a series of instructions that, in effect, tell it what buttons to push, and in what order to push them. Most of what computers can do is based on their ability to:

Add two numbers together

Subtract one number from another

Compare numbers or symbols to see if they are the same

The power computers possess comes from their ability to perform multiple functions simultaneously and process tremendous amounts of information in what amounts to the blink of an eye. They are at their best when used for large volume, highly defined tasks.

In order to function effectively; a computer requires:

An input device, so that information can be given to it Information (or data)

A program to tell it what to do, or how to work, with that data An output device so that it can display or print out whatever is requested of it

These computer concepts can be found at work in any number of things with which most of us have daily contact. For example:

Scanners such as that pictured in Figure 11, used in the checkout stands at the supermarket (including some that have voice synthesizers)

FIGURE 11. Computerized scanner at a grocery store. Photo by author.

Cash registers at fast-food and other restaurants that not only keep track of cash and sales but that also tie into inventory control and reordering. Automatic tellers programmed to transfer money from your account on demand, or perform other services (see Figure 12) Household appliances, such as microwave ovens and televisions. Automatic gasoline pumps (pictured in Figure 13), that record a purchase, turn on the pump and keep track of how many total gallons a station is using Automobile systems that calculate miles per gallon, trip times, and distance. Computers are able to do all these things because they make no distinction between numbers and symbols. Rather, they translate everything into electrical impulses, which form patterns that have meaning for the computer. These patterns form the basis of the computer’s numbering system by taking the electrical pulses and converting them to a binary system. Binary consists of exactly two numbers: 1 (a pulse of electricity) and 0 (no pulse). By stringing is and Os together, the computer converts whatever data it is given into terms it can understand. For example, the binary equivalent of the number 10 is 1010. Binary codes are also assigned to the characters on the keyboard, so that letters, symbols, and spaces are treated the same way numbers are. This is accomplished through an international conversion code called the American Standard Code for International Interchange (ASCU). Under this code for example, the letter “B” on a keyboard is given the numeric value 66, which the computer can convert to its binary equivalent of 01000010. When the computer is finished processing the information it is given, it translates everything back into numbers and symbols that we understand. For most of us, there is no reason to ever use binary in communicating with a computer because this is already on the software. The decoding instruction the computer needs to interpret everything is programmed into it by the manufacturer.

FIGURE 12. Computers help make breaking more convenient  through the automated tellers.

FIGURE 13. Computerized gas pumps calculate sales customer’s account. 

 

Before we finish : If you need more help or have an opinion or suggestion Please leave a comment Below. This is a Do-Follow Blog leaving a comment will also help your blogs Google rank.