Monday, January 28, 2008

COMPUTER SOFTWARE

For the EDP system to analyze data, update files, and print out information, it must have a programs designed for these purposes. Stored programs tell the computer what steps to take, what data to work on what to do with the results. Software commonly includes such programs as well as any operating aids that extend the capabilities of the computer.

Therefore, program in programming languages which combine precision of expression with a certain closeness to natural languages on the one hand and the problem to be solved on the other. Programs written in such languages are largely independent of the characteristics of a particular computer; they are usually easily portable from one machine to another.

Software also includes utility programs ( for example, sorting routines) that have been written by systems programmers, rather than users, and are stored in the memory of the computer system.

The operating system, along with the language translators, programs for data management and communication, and utilities programs, constitute the essential software of an electronic data processing system. An EDP system also contain" Firmware" or microcode instructions, developed by the computer manufacturer to permit tailoring of the system to meet particular data processing requirements.

Sunday, January 27, 2008

COMPUTER HARDWARE

The term hardware refers to the physical equipment or components of an electronic data processing system. It may also be referred to as a machinery that performs the machines of operations. Each component is designed to perform one or more of the following functions; data preparation, input, processing, storage, and input.

An electronic data processing system includes a number of functionality separate devices that constitute its hardware : the memory system where data and instructions are stored, and input/output devices for communication with environment of the system.

ELECTRONIC DATA PROCESSING

There are different types of data processing systems and each performs one or more required operation(s) on data by means of various devices. When a machine performs most of the required operation, the system is called an automatic data processing (ADP) system. More particularly, when that machine is an electronic digital computer, the system is described as an electronic data processing (EDP) system or simply as a computer system.

In the broadest terms, an electronic data processing consist of ; hardware, software, and people ware.

In electronic data processing, a user does not have to deal directly with the physical devices( hardware of the EDP system. Instead a special service programs, stored in the computer memory, provide an interface between the user and the equipment . These programs, called systems software, simply the task of the programmer and. the applications software control the use of the hardware.

Tuesday, January 22, 2008

EARLY DEVELOPMENTS IN ELECTROMAGNETIC DATA PROCESSING

All the early machine, except for Babbage's analytical engine, were essentially single- purpose devises. These machines were designed to perform a specific task or set of tasks. The major innovation of the first modern-age machines was its capability to perform automatically a long sequence of varied arithmetical and logical operations.

The completed device was known as the MARK I digital computer. The first electromagnetic digital computer to be put into full operation was built as a secret wartime project. This machine, which used vacuum tubes, was called the "ENIAC" computer. Following the war, work began on the "EDVAC", a computer which worked on the stored program concept.

1. MARK I = The official name of MARK I was Automatic Sequence Controlled Calculator. It was approximately 50 feet long and 8 feet high, and consisted of some 700,000 moving parts and several hundreds miles of wiring. The MARK I could perform the four basic arithmetic operations and could locate information stored in tabular form. It processed numbers up to 23 digits long, and could multiply three eight-digit numbers in a second. Internal operations were controlled automatically with electromagnetic relays and the arithmetical counters were mechanical. It was not an electronic computer but was rather an electromechanical one since it was powered by an electric motor ans used switches ad relays. It was also the first automatic general-purpose digital computer.

2. THE ENIAC = was developed during the the period 1943 to 1946. It was the first Large - scale vacuum-tubes computer. The ENIAC is an acronym for Electronic Numerical Integrator and Calculator. It consisted of over 18,000 vacuum tubes and required the manual setting of switches to achieve desired results. It could perform 300 multiplications per second. Operating instructions were not stored internally; rather they were fed trough externally located plugboards and switches.

3. THE EDVAC = In 1946 a Hungarian-born mathematician John von Neumann proposed a modified version of the ENIAC. The modified version, EDVAC (Electronic Discrete Variable Automatic Computer), would differ from the ENIAC in two profoundly important respects. First, the EDVAC would employ binary arithmetic. The MARK I and the ENIAC both used decimal arithmetic in all their calculations. VonNeumann showed that binary arithmetic would make for much simpler computer circuitry. Second, the EDVAC would have stored- program capability. He also proposed wiring a permanent set of instructions within the computer and placing these operations under a central control. He further proposed that the instructions codes governing the operations be stored in the same way that the data were stored - as binary numbers.

The EDVAC was not the first stored-program machine to go into operation. That honor went to an English-made computer, the EDSAC (Electronic Delay Storage Automatic Calculator).

4. COMPUTER GENERATIONS = Fourth-generation computers represent the state of the art today and the fifth generation is on the way. The term"generation" it refers to major developments in electronic data processing.

The Generation are:
  • First Generation Computers
  • Second Generation Computers
  • Third Generation Computers
  • Fourth Generation Computers
6. FIRST GENERATION COMPUTERS(1951- 1959)
With the beginning of the Korean War in 1950, the demand of many different kinds of computation increased greatly. The appearance of the first commercial computer, the UNIVAC, in 1951, marked the beginning of computers belonging to the first generation. The major innovation s then were the use of vacuum tubes in place of relays as a means of storing data in memory and the use of the stored-program concept. The addition of memory made the punched card system and the calculators virtually obsolete. The wire board was replaced by computer programs written in a new languages for processing.

No educational programs precisely met the requirements of the technology when the first generation computer became available. Early users were pioneering in the use of a new tool not designed specifically for their particular needs. Computer installations had to be staffed with a new breed of workers who initially had to cope with the necessity of preparing programs in a tedious machine language.

7. Second Generation Computers( 1959- 1964)

Solid-State components( transistors and diodes) and magnetic core storage formed the basis for the second generation of computers. The new transistor technology made the previous generation obsolete. A transistors performs the same functions as a vacuum tube, except that electrons move through solid materials instead of through a vacuum.

8. Third Generation Computers (1965- 1970)

Integrated solid-state circuitry, improved secondary storage devices, and new input/output devices were the most important advantages in this generation. The new circuitry increased the speed of the computer by a factor of about 10, 000 over the first generation computers. Arithmetic and logical operations were now being performed in microseconds or even nanoseconds.

9. Fourth Generation Computers ( 1970- Present)

The major innovations were in the development of microelectronics and in the development of different areas in computer technology such as; multiprocessing, multiprogramming, miniaturization, time-sharing, operating speed, and virtual storage. Because of microprocessors, the fourth generation includes large greater data processing capacity than equivalent-sized third generation computers .

Monday, January 21, 2008

THE HISTORY OF COMPUTERS

The electronic digital computer has had, and continues to have, a profound impact not only on business and science but on society and general. History studies are extremely useful in evaluating that impact and understanding the process of change that leads to even more advanced technologies.

Thus, the study of history can help to explain what can and cannot be reasonably expected from technological developments.

THE EARLIEST COMPUTING DEVICES

The earliest data processing equipment will manual-mechanical devises due to the absence of electricity and adequate industrial technology.

1. Abacus = The first manual data processing device was the abacus which was developed in china. The device has a frame with beads strung on wires or rods and arithmetic calculations are performed by manipulating the beads.

2. Napier's Bones= John Napier was a Scottish mathematician who became famous for his invention of logarithms. The used of "logs" enabled him to reduce any multiplication problem. His "bones" are set of eleven rods side by side products and quotients of large numbers can be obtained. The sticks were called " Bones"because they were made of bone of ivory.

3. Oughtred's Slide Rule = Although the slide rule appeared in various forms of Europe during the seventeenth century. It consists of tow movable rulers placed side by side. Each ruler is marked off in such a way that the actual distances from the beginning of the ruler are proportional to the logarithms of the numbers printed on the ruler. By sliding the rulers one can quickly multiply and divide.

4. Pascal's Calculator= Blaise Pasacal was a French mathematician and experimental physicist who was one of the first modern scientists to developed and build calculator. He devised a calculating machine that was capable of adding and subtracting numbers. The machine was operated by dialing a series of wheels.

5. Leibniz's Calculator = Like Pascal, Gottfried Leibniz was a seventeenth -century scientist who recognized the value of building machines that could do mathematical calculations and save labor too.

6. Babbage's Analytical Engine = This machine was based on the principle that, for certain formulas, the difference between certain values is constant. This typed of procedure was used frequently for producing astronomical tables, which are particularly useful

7. Hollerith's Punched-Card Machine = Herman Hollerith, a statistician with the US Bureau of the Census, completed a set of machines to help process the results of the 1890 census. Using 3 by 5 inch punched cards to record the data, he constructed an electromagnetic counting machine to sort the data manually and tabulate the data.



Saturday, January 19, 2008

METHODS OF PROCESSING DATA

Different methods are now used in data processing employing quick response digital computer systems. These methods have been developed to increase the timeless, effectiveness, and availability of information. They allow users to react more rapidly to changing conditions, reduce waste in the use of time and other resources, and permit quick follow-up o creative ideas.

1. Batch Processing. Batch processing is a technique in which data to be processed or programs to be executed are collected into groups to permit convenient, efficient, and serial processing. It is the simplest form of data processing. With this method, data is entered into the information flow in a large volumes, or batches.

Advantages of Batch Processing

a. Economical when a large volume of data must be processed
b. the most appropriate methods for those application( e.g. payroll) where the delay caused by accumulating data into batches does not reduce the value of the information.

Limitations of batch processing

a. It requires sorting prior to processing.
b. reduces timeless in some instances it takes a fixed time interval before current data is added, and requires cannot be effectively made between processing intervals
c. requires sequential file organization this may prove to be handicap if the current status of a record near the end of a file needs to be determined.

2. On-line Processing. The term on-line refers to equipment or devices under the direct control of the central processing unit(CPU) of a computer. An on-line operation, then is one which uses devises directly connected to the CPU either for data entry or inquiry purposes. That is, with a terminal we can either enter data or inquire about the status of some record or file that is stored by the computer.

On-line processing has been developed for certain uses as an answer to the batch processing deficiencies. Information contained in any record is accessible to the user without the necessity of a sequential search of the file and with a fraction of a second after the inquiry message has been transmitted. Thus, on-line processing systems may feature random and rapid input of transactions and immediate and direct access to record contents as needed. However, on-line processing and direct access to records require unique hardware ans software. It will also require software security provisions to prevent confidential information from falling into unauthorized hands and prevent deliberate or accidental tampering with data and program files.

3. Real-time Processing. Real-time processing is a method of data processing which has the capability of a fast response to obtain data from an activity or a physical process, perform computations, and return response rapidly enough to effect the outcome of the activity or process.

4. Distributed Processing. The most complex level of computer processing, distributed processing, generally consists of remote terminals linked to a large central computer system to help the user conduct inquiries about accounts, process jobs, or other data processing operations.
In distributed processing network a large number of computers and significant software resources is being shared among a large number of users. It may be used of be used by a single organizations.

Advantages of distributed systems are:

1. Central processor idle time is reduced.
2. sophisticated computers and growing library of applications programs may be immediately available to end-users whenever needed.
3. skilled professionals are available to help users developed their own specialized applications.
4. managers maybe able to react more rapidly to new developments and interact with the system i order to seek solutions to unusual problems.

Disadvantages

1. the reliability and cost of the data communications facilities used, and the cost and quality of the computing service received, may e disappointing in some cases.
2. input/output terminals are often rather slow and inefficient.
3. provisions for protecting the confidentiality and integrity and integrity of user programs and data files are generally ineffective against a skilled penetrator.





Monday, January 14, 2008

AREAS OF DATA PROCESSING

Data processing maybe classified as either scientific or business in nature.

1. Business Data Processing (DBP). Business data processing is characterized by the need to established, retain, and process files of data for producing useful information. Generally, it involves a large volume of output. For example, a large retail store must maintain a record for each customer who purchases on account.

2. Scientific Data Processing (SDP). In science, data processing involves a limited volume of input and many logical or arithmetic calculations.

3. Data Processing Operations
A data processing processing procedure normally consists of number of basic processing operations performed in some order. The means of manual, electromechanical, or electronic methods are used. Many businesses find that the best solution to their processing requirements is to use a combination of methods.

A. Recoding. Recording refers to the transfer of data onto some form or document. It relatives to the documentation of intermediate figures and facts resulting from calculations.

B. Verifying. Since recording is usually a manual operation it is important that recorded data be carefully checked for any errors. This operations called verifying.

C. Duplicating. It is sometimes necessary or desirable to copy or duplicate data. This operation consists in reproducing the data onto many forms or documents. Duplicating maybe done while the data being recorded manually, or it may be done afterwards by some machines

D. Classifying. This operation separates data into various categories. Identifying and arranging items witch like characteristic into groups or classes is called classifying.

E. Sorting. Arranging data in a specific order is called sorting. After the data are classified, it is usually necessary to arrange or rearrange them in a predetermined sequence to facilitate processing. Sorting is done in an alphabetic or numeric order and the data item which determines the sorting is called the key. Numeric sorting usually requires less time than alphabetic sorting in machine-based processing systems and it therefore generally used.

F. Calculating. Arithmetic manipulation of the data is known as calculating. It is a crucial phase of data manipulation, because the outcome of this operation becomes part of the output. In the calculation of an employee's pay.

G. Summarizing and Reporting. In this operation, a collection of data is condensed and certain conclusions from the data are represented in a meaningful format. To be a value, data must often be condensed or sifted so that the resulting output reports will be clear, concise and effective. Reducing masses of data to a more usable form is called summarizing.

H. Merging. This operation takes two or more sets of data, all sets having been sorted by the same key, and puts them together to form a single sorted set of data.

I. Storing. Placing similar data into files for future reference is storing. Storage is done by any o the following methods;
a. manual - such as in a ledger book, b. electromechanical- in the form of punched cards and c. electronic- by magnetic tape, disk, and main memory of the computer. Data should be stored only if the value of having them in the future exceeds the storage cost.

J. Retrieving. Recovering stored data and/ or information when needed is the retrieving step. Retrieval methods range from searches made by file clerks to the use of quick responding inquiry terminals that are connected directly to a computer .

K. Feedback. Feedback is the comparison of the outputs. and the goal set in advance ; any discrepancy is analyzed, corrected, and feedback to the proper stage in the processing operation.

















EXPANDED DATA PROCESSING CYCLE

Frequently, three more steps are added to the basic data processing cycle to obtain the expanded data processing cycle.

1. Origination. Origination is a step which refers to the process of collecting the original data, An original recording of the data is called a source document.

2. DISTRIBUTION. This step which refers to the distribution of the output data. Recordings of the output data are often called report documents.

3. STORAGE. Storage is crucial in many data processing procedures. Data processing results are frequently placed in storage to be used as input data for further processing at a later date. The two flow lines between the processing box and the storage box indicate the interaction of these two steps. A unified set of data in storage is called a file. Usually a file consist of a collection of records, where each record contains similar data items, and a collection of related files called a data base.

Sunday, January 13, 2008

DATA PROCESSING CYCLE

Regardless of the kind of data processed or the kind of device or equipment used, all data processing systems involve at least three basic steps : Input, Processing, and Output. These three steps constitute the data processing cycle.

1. INPUT=In this steps the initial data, or input data, are prepared in some convenient form of processing. The form will defend on the processing machine.

For example, when electromechanical devises are used.


2. PROCESSING= In this step the input data are changed, and usually combined with other information, to produce data is more useful form. Thus, paychecks may be calculated from the time cards, or a summary of sales for the month maybe calculated from the sales orders. The processing step usually involves a sequence of certain basic processing operations.

3. OUTPUT= Here the results of the preceding processing steps are collected. The particular form of the output data depends on the use of data.

DEFINITION OF TERMS

Data is defined as any collection of facts. Thus, sales reports, inventory figures, test scores, customers, names and address, and weather reports are all examples of data. Data processing is the manipulation of data into more useful form. It is the modern name for paperwork and involves the collecting processing, an distributing of facts and figures to achieve a desired reports.

Data Processing includes not only numerical calculations but also operations such as the classification of data and the transmission of data from one place to another.

Data processing system refers to the equipment or devices and procedures by which the result is achieved.

Saturday, January 12, 2008

CATEGORIES OF DATA PROCESSING

Modern data processing employing machines and other devices falls into two basics categories, mechanical data processing and electronic data processing. In some data processing operations, all work is still done using manual procedures.

A major difference between the two categories is that the mechanical system usually require constant manual intervention between the different data processing operations, whereas in an electronic system the different operations are performed automatically with a minimum manual intervention.

The types of machine employed in either system usually vary from one user to another. However most of the general concepts in data processing still remain applicable.

DATA PROCESSING

All through the different stages of civilization, man has always tried to look for ways to simplify work and to solve problems more efficiently. Many problems involve numbers and quantities, so man started looking for easier ways to count, and to add, subtract, multiply, and divide. AS society has grown both size and complexity, so has the data that is generated within it.

Data is off little value if it remains in the form of quantities and numbers.Data is processed to produce accurate records.

INTRODUCTION TO COMPUTER CONCEPTS

The deferent lessons focus on major topics, such us data processing, history and classification of computers, capabilities and limitations of computers, computer systems hardware, data recording, media, computer system software, algorithms, number system and an introduction to basic language programming and you can also learn from here all basic information to all programming languages.

I believe that you will learn a lot of things to this site and it can help your self to know what is computer is all about.