GHS/Computer Studies/History of computing

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The mechanical era:

This was the period before 1900, when counting was done using stones or sticks to count and keep records. Later counting devices were introduced like the abacus. Abacus was the most significant and earliest computing tool that marked the existance of modern computers. It would perform all the arithmetic operations like addition, subtraction, division and multiplication. The major disadvantages was losing truck while calculating resulting into wrong figures. Other personalities who contributed to the current technolgy included:

Napier John

Blaise Pascal

Gottfried Wilheim Von Leibniz

=Jacquard Joseph Marie

Jacquard invented the machine called a jacquard loom used in weaving. It was the first machine that used punched cards which stored information for example the different weaving patterns such that the same patterns would be utilised over and over again to get the same product. The ability of his machine to store information contributed alot to the computer evolution and the textile industry

Charles Babbage

He invented the difference engine which was used for only calculations hence came up with another device called the analytical engine. The analytical engine used punched cards to store information , it could do all the arithmetic operations and would be programmed by the user to do different tasks. It was because of this device that babbage is called the "father of the computer"

Herman Hollerith

He invented an electromechanical tabulator which was used to tabulate data. The machine was for accumulating and classifying information therefore founded the field of data processing. and also started the IBM( iternational business machines. however his device was only imited to tabulation.


Research: The teachers and students research on various topics in different subjects. Information is obtained from online libraries, universities, government agencies, news organizations like CNN, BBC etc Doctors can also research on drugs of different diseases and the cause of such diseases.

2. Communication:

For example students communicate with parents by sending email or sms. Business partners with others who are involved in joint activities. Also doctors communicate among them selves to share opinions, patients communicating with doctors and connecting to major medical centers through internet for treatment and advice.

3. Storage:

The schools can keep students data, classroom notes and assignments for easy editing and updating, keeping accounts records, government can store population data , social welfare records, tax records and other information. Business people can keep record of their customers and

In a hospital records about patients appointment, personal and medical history etc can be kept.

4. Make documents:

For example school news letters and magazines, circular and letters to parents, time tables and rotas and other notices on notice board, writing reports e.g. house report, class report etc The government can make voter’s cards, birth and marriage certificates, calendars etc. The organizations can also make payrolls for their employees.

5. Calculation:

E.g. using when making budgets spreadsheet application can be used making work easy. Students marks can be entered into the computer for quick computation, positioning and grading.

6. Employment: it is a source of employment for computer trainers, businesses that provide internet services, internet cafes, printing services etc.

7. E-learning (electronic learning):

This is learning offered over the internet where teachers and students exchange classroom instructions and assignments via internet and there is no face to face interaction.

8. E-commerce:

Its electronic buying and selling of goods using the internet. There a number of websites were goods are sold.

9. E-banking:

this is where customers easily and quickly exchange money using computers. Today there are ATM which help customers to withdraw cash, check balance, deposit money, transfer money to different accounts, get a brief statement etc.

10. Entertainment:

Through watching movies, paying games, listening to music, searching for jokes and magazines, chatting with friends etc.

11. Advertising for example goods sold.

12. Used in libraries:

To keep updated record of books and other reading materials, search for titles of books instead of manual cards, data retrieval is faster etc.


Information processing is the change or processing of information in a manner detectable by an observer Data refers to raw and unprocessed facts figures and symbols. E.g. a, b. 2,8 , < etc Information refers to processed data that is organized and meaningful to the user for example reports, a letters, an assay, song, mathematical formulas, words etc

Information technology (IT): Refers to the use of electronic computers and other technologies to convert, store, protect, process, transmit, and securely retrieve information

OR Is a branch of engineering that deals with the use of computers and telecommunications to retrieve, store and transmit information. OR It refers to both hardware and software that are used to store, retrieve and manipulate information.

The information processing cycle

Information technology is the combination of computer and communication technologies to process data into information. Information processing cycle: It refers to a series of input, process, output and storage activities.

Live space fr diagram:

The five basic stages of information processing

1.Collecting data refers to capturing of data and recording it on paper or other media. 2. Preparing data: copying, grouping, or arranging data in a more convenient way for input. 3. Input of data: entering the data into the processing system. Data entered at this level should be accurate and valid.

4. Processing of data: It involves calculating or manipulating the input data and storing the results for future use. 5. Output of information: its giving out of processed results in a readable form eg a report.

Common Information systems

These include the following:

1. Batch processing system:

Its where data is collected together in a batch before processing starts Batch processing is most suitable for tasks where a large amount of data has to be processed on a regular basis. Examples of batch processing systems include payroll systems and examination report card systems. NB: A piece of work for batch processing is called a job

Other examples of batch processing include; (i) Clearing cheques. When a cheque is deposited into the bank account it is cleared ie checking that the person who wrote the cheque has enough money on account to cover the cheque. This is done for different cheques which are later processed as a batch.

(ii) Generating bills Organizations create bill, or invoice, for goods or services that have been supplied to a customer. They usually generate a group of bills at a scheduled time.

For example payroll systems and examination card systems.

Advantages of batch processing

1. It can be carried out automatically when the computer is not used for example at night. Therefore the organization will be doing alot of work with its computer.

2. Hardware required is cheaper than real time systems.


1.There is delay before work is processed and output obtained.

2. Tis master file with all important data of the computer is upto date therefore not suitable for use where updated data is required eg booking seats on plane etc.

2. Real time systems: is one that processes data without significant delay. e.g. of real-time processing systems include anti-missile defense systems, airplane landing control system, flight simulation systems, electronic fund transfer systems, and tickets reservation systems.

Advantages of real time systems

1. There is no significant delay for response.

2. Information is always up-to-date.

3. Output from the computer may be used to adjust and improve the input.


1. A computer must be dedicated solely to the task.

2. The computer must be continually online.

Examples of real time systems include a

(a) library loan system where each transaction is handled there and then when information about the book and borrower are recorded on the library database.

(b) POS (point of sale terminal): used to record purchases at the point where the consumer purchases the product or services. Mainly found in retail outlets. (c) Reservation systems e.g. booking a seat on a train or plane.

3. An interactive processing system:

Is one that involves communications between the user and the computer during processing. E.g. ticket reservation, EFTS (electronic fund transfer systems), and point of sale systems.

4. Multi-tasking system: Is one that can handle a number of different jobs at the same time. e.g. printing a document and listening to music at once.

Note: Both batch and interactive jobs can be run in a multi tasking environment.

5. Time-sharing system : it allows multiple users to share time on a single computer.

It can also be referred to as a system that allows different users to independently run different programs at the same time. Example is bankcard system, which allows hundreds of people to access the same program on the mainframe computer of the bank at the same time. The computer works so fast that each user seems to be the sole user of the computer.

6. Multi-user system is a time sharing system that allows different users to independently run different programs at the same time. Each user is given a time slice of the CPU time however the computer is very fast in processing data that it will seem as if only one user is using the computer.

Examples include bank card system where many people share the same program on the bank's mainframe computer.

Advantages of using computers for information processing include

1. Tasks can be completed faster because computers work at amazing speed.

2. Computers can process large amounts of data and generate error-free results, provided that the data is entered correctly.

3. Computers can store enormous amounts of data for future use.

4. The high reliability of components inside modern computers

5. enables computers to produce consistent results.

6. Efficiency and productivity can be raised.

7.Running cost becomes lower in the long term.

8. Tasks can be completed with little human intervention (i.e., automatic).

9. Overall security can be raised due to less human intervention.

10. The management can observe new information and new trends more quickly.

11. Customer services can be improved due to more efficiently management and operations.

12. Computers with communicating capability can share data and information with other computers.

Disadvantages of using computers for information processing include

(i) Initial investment cost can be high.

(ii) Extra cost is required to employ specialized staff to operate and design the data processing system.

(iii) Some jobs may be lost due to computerization and thus lower the morale of staff members.

(iv) Some staff has to be trained or retrained which is costly and time consuming.

(v) Face-to-face interactions among staff may be reduced being replaced by online communication.

(vi) Health hazards arising from misuse of computers or when precautions are not put in place.


A computer is an electronic device that accepts user input, processes it according to the given instructions, outputs the information and stores the results for future processing.

A computer is comprised of hardware and software.

the computers have been classified or categorized in the following ways:-

  • According to physical size and processing power.
  • Purpose
  • Function

Classification according to physical size and processing power.

The size of computers varies widely from very tiny to huge computers. Their processing power is also different and examples in this category include;

  • Super computer
  • Mainframe computer
  • Mini computer
  • Micro computer or personal computer
  • Server computer

Super computer

It is the fastest, largest, most expensive and powerful computer. super computers process trillions of instructions in a second. These computers can be used for weather forecasting, weapon research, space exploration , used by government to do heavy jobs and also by industries to design their products etc. They have the following characteristics.

1. can perform many complex calculations in a fraction of a second.

2. Generate alot of heat due to their huge processing power.

3. Require special cooling systems for the CPU i.e using flourocarbon liquid.

4. They are giant computers due to extreme weight and are kept in special room.

5. They produce massive amounts of data in a very short period of time.

super computers are used in scientific research for example nuclear physics and petroleum research, designing weapons for defence, weather forecasting , space exploration etc. they can also be used for specific purpose satellite launching , in robots, firing misilles.

Mainframe computer

These are mostly found in government agencies, big organizations and companies like hospitals , banks , air line reservations because of its capability to retrieve huge amounts of data on regular basis. Mainframe computers have the following characteristics;

1. They are less powerful and less expensive than super computers. They can process millions of instructions per second.

2. They are big in size though not like giant computers.

3. Store large amounts of data and perform many tasks at the same time.

4. Can handle hundreds of users connected ate the same time.

5. Process data and perform complex calculations.

6. Support variety of peripherals.

It should be noted that mainframe computers can handle both scientific and commercial problems.

Mini computer

This offers less than mainframe in terms of work and perfomance and mostly used by small business people. they have the following characteristics;

1. Slightly smaller than mainframes.

2. Not powerful and fast as mainframes.

3. Cheaper compared to mainframes for small organizations.

4. Support fewer peripheral devices.

5. Have smaller storage capacity than mainframes.

6. More powerful than personal computers and perform a number of different tasks.

Minicomputers are used in scientific laboratories, research institutions etc where automation is required. They are also used in accounting , word processing, database management etc

Micro computers OR personal computer

It is the smallest, cheapest and relatively least powerful computer. they are slower than previous computers and cannot store as much information as super, mainframe and minicomputer. personal computers are used by on person at a time hence their name. they also have very small micro processors compared to the first computers. These computers are mostly used in homes schools, business and other communication centres and are in various types forexample:-

1. desktop computer It is desined to be placed on top of desk for example in office or at home therefore it is not portable.

2. Laptop it is a portable computer like brief case and can be used while placed on laps.

3. palmtop. It is held in the palm when used and can also fit in a pocket eg PDA(persol digital assistant). These computers have a non standard keyboard and donot have disk storage devices.

4. pen computer They are portable and use a pen like device

5. Handheld

6. Notebook computer

7. Tower computer

8 Network computer

9. Server computer

10. Workstation