COMPUTER FUNDAMENTALS
STEPS INVOLVED IN PROGRAMMING:
1. Defining the problem
2. Designing the algorithm
3. Coding the program
4. Testing and debugging the program
5. Implementing the program
6. Maintaining the implementation of the program
1. Defining the problem: It involves recognizing the problem identifying exactly what the problem is determining the available input and desired output deciding whether the problem
can be solved by using the computer.
2. Designing the Algorithm: An algorithm is a finite set of step-by-step instructions for solving problems.
3. Coding the Program: It involves the actual writing of the instructions in a particular language. That is code languages that are C++, C, Java, Python, etc.
4. Testing and Debugging the program: After coding the program must be tested to ensure that it is correct and correct with no errors.We will test and dedug the program. These types of errors or bugs can found which are
1. Syntax error
2. Logic error
3. Run time error
Syntax Error: Syntax error when the rules are violated while coding the program.
Logic Error: Improper coding of individual statements either or a sequence of statements cause this type of computer program error.
Run Time Error: This error in a computer stops its execution. It may be caused by the entry of invalid data.
Implementation of the program: After a program has been listed and debugged, it can be installed and implemented.
Maintaining and Upgrading the Program: After a program is developed and it should be upgraded as per the requirements of the user. Maintaining and upgrading the program is after the process.
ALGORITHM
The algorithm is invented by an Arabian inventor. It is step by step solving procedure.
FOUR CHARACTERISTICS OF THE ALGORITHM:
1. It should involve a finite number of steps
2. It should be clear without ambiguity.
3. It should be clear.
4. It should lead to unique solutions for the program.
STEPS INVOLVED IN ALGORITHM DEVELOPMENT
1. Clearly understand the problem statement so that the proper algorithm can be evolved.
2. Study the output to be generated so that the input can be specified.
3. Design the process in which you are produced in the algorithm.
4. Refine the algorithm.
5. Test the algorithm by giving the test data to see if the desired output is generated.
Advantages of the Algorithm:
1. It is a step-by-step solution given by the problem. It is very easy to do.
2. It has got a definite procedure that can be exacted within a set time period.
3. It is easy to first develop an algorithm and then it convert into a flow chart.
4. It has got a beginning and an end within which there are definite procedures to produce outputs in a specific period.
5. It is easy to debug.
6. It is independent of programming languages.
Disadvantages of Algorithm: It is time-consuming and cumbersome as an algorithm is developed first converted into flowcharts and then into a computer language.
FLOW CHART
It is a diagrammatical representation of the solution. It gives pictorial representation. In this flow chart symbols are used.
Symbols used in a flowchart:
The algorithm flowchart for the sum of three rows:
ALGORITHM:
Step-1: Read the three numbers x, y, z.
Step-2: Sum=x+y+z
Step-3: Print the sum
Step-4: Stop
Flow Chart:
The algorithm to find out the largest of three numbers:
ALGORITHM
Step-1: Read the three numbers a, b, and c.
Step-2: If A>B then go to step 5. Else go to step 3.
Step-3: If B>C then the print B is greatest and go to step 7.
Step-4: Print C is the greatest and go to step 7.
Step-5: If A>C then print A as greatest and go to step 7.
Step-6: Print C is the greatest.
Step-7: Stop
FLOWCHART:
NEED FOR OPERATING SYSTEM
The operating system can be defined as system software that acts as an interface and the system and manages resources in an efficient way. The goal of operating system is use smoothly and fastly.
1. All computers have an operating system that is used for starting the computer and running all the other programs.
2. The operating system performs important tasks like receiving input from the keyboards and mouse, sending information to the screen.
3. Operating system provides an interface between hardware and the user. If the operating system does not exist then working the system will become very difficult.
4. Operating system increases when the efficiency of the computer system.
5. Error handling is done by the operating system. If the operating system does not perform the handling, it is to be performed by the user.
6. OS is so many types it is present in phones, laptops etc.
VARIOUS OPERATING SYSTEMS:
1. Character-based operating system
2. Graphic User Interface system
3. Personal Computer OS
4. Network OS.
Character-Based Operating System: Provide an interface to the user through a set of commands.
Graphic User Interface System: GUI OS provides the interface through a set of icons. These operating systems are friendly.
Personal Computer OS: The systems are used to work on PCs.
Network Operating system: This is an operating system that have includes special functions. for connecting computers and devices to a local-area network(LAN).
DOS COMMANDS
DOS uses two kinds of commands classified as either internal or external. When you boot DOS by starting the computer certain DOS commands get loaded into RAM within the DOS command processor. These are called DOS commands. When you invoke one of these commands, DOS simply locates the command in the memory and executes it. You don't require these commands to be present either on a disk or hard disk. On the other hand, external commands reside on the disk. Each time you invoke an external command. DOS must load the command file into memory by reading from either the diskette or the hard disk whenever DOS finds the command file. It should allow the instructions of window.These are small programs. DOS means disk operating command.
