<h1><strong>MECHANICAL COUNTING AND CALCULATING DEVICES</strong></h1> CONTENT <ol> <li>Mechanical Counting and Calculating Devices</li> </ol>   <h2><strong>Mechanical Counting and Calculating Devices</strong></h2> As a result of the disadvantages of the early counting devices, more advanced mechanical counting and calculating devices were invented. Some of these devices are; <ol> <li>Abacus (Chinese)</li> <li>Napier’s Bone (John Napier)</li> <li>Slide Rule (William Oughtred)</li> </ol>   <h3><strong>THE ABACUS </strong></h3> The Abacus is made up of beads threaded on iron rods. The iron rods are fixed to a rectangular wooden frame. It is used for addition and subtraction only. It could not carry out complex mathematics. The Abacus was early used for arithmetic tasks, it was developed in China about 5000 years ago. It was successful that its use spread from china to many other countries. <img class="size-full wp-image-15138 aligncenter" src="https://classhall.com/wp-content/uploads/2017/07/computing-devices-the-abacus.jpg" alt="historical development of computers - Early counting and calculating devices - Abacus" width="452" height="166" />

<h1><strong>IMPORTANCE OF THE COMPUTER AS A TOOL FOR DATA PROCESSING</strong></h1> CONTENT <ol> <li>The Importance of the Computer as a Tool for Data Processing</li> </ol>   <h2><strong>The Importance of the Computer as a Tool for Data Processing</strong></h2> The computer is a very unique electronic device and has certain features and characteristics that distinguish it from other machines. These include: 1.<strong> Speed:</strong> Computers are very fast; they can perform tens of millions of operations per second. This is necessary for predicting weather forecasts, performing scientific research and even producing thousands of bills for utility companies. 2.<strong> Accuracy:</strong> Computers are very accurate. Errors only occur if there is an error in hardware, software or data. When errors occur it is usually because of some human error, since computers can only do what they are programmed to do. 3.<strong> Storing large amounts of information in a small space:</strong> There are many storage media that can be used to store large volumes of data and information. For example, a single CD-ROM disk can save the equivalent of a shelf of books in the library.

<h1><strong>HISTORICAL DEVELOPMENT OF COMPUTERS</strong></h1> CONTENT <ol> <li>Electro-mechanical Counting Devices</li> </ol>   <h2><strong>Electro-mechanical Counting Devices</strong></h2> These are counting devices that could be operated both electrically and mechanically. Electro-mechanical devices include the following: <ol> <li>Speeding Clock</li> <li>Blaise Pascal machine</li> <li>Gottfried Leibniz Machine</li> </ol>   <h2><strong>SPEEDING CLOCK OR CALCULATING CLOCK</strong></h2> In 1623 and 1624, reported his design and construction of what he referred to as an arithmetical instrument that he has invented but which would later be described as a (calculating clock). The machine was designed to assist in all the four basic functions of arithmetic (addition, subtraction, multiplication and division). Amongst its uses, Schickard suggested it would help in the laborious task of calculating astronomical tables. <strong>The machine could add and subtract six-digit numbers, and indicated an overflow of this capacity by ringing a bell. </strong>The adding machine in the base was primarily provided to assist in the difficult task of adding or multiplying two multi-digit numbers. To this end an ingenious arrangement of rotatable Napier's bones were mounted on it. It even had an additional "memory register" to record intermediate calculations. Schickard’s machine was not programmable. <img class="size-full wp-image-20075 aligncenter" src="https://classhall.com/wp-content/uploads/2018/06/historical-development-of-computer-early-counting-devices-speeding-clock-or-calculating-clock.jpg" alt="Historical development of the computer - Electro-mechanical counting devices - speeding clock or calculating clock" width="219" height="192" />

<h1><strong>ELECTRO-MECHANICAL COUNTING DEVICES </strong></h1> CONTENT <ol> <li>Electro-mechanical Counting Devices</li> </ol>   <h2><strong>Electro-mechanical Counting Devices</strong></h2> <h3><strong>JOSEPH JACQUARD’S LOOM </strong></h3> The Jacquard machine is a device fitted to a power loom that simplifies the process of manufacturing textiles with such complex patterns as brocade, damask and matelassé. It was invented by Joseph Marie Jacquard in 1804. The loom was controlled by a chain of cards, a number of punched cards, laced together into a continuous sequence. Multiple rows of holes were punched on each card, with one complete card corresponding to one row of the design. The Jacquard loom was the first machine to use punch cards to control a sequence of operations. <img class="size-full wp-image-15143 aligncenter" src="https://classhall.com/wp-content/uploads/2017/07/computing-devices-jacquard-loom.jpg" alt="Historical development of the computer - electro-mechanical counting devices - The jacquard loom" width="184" height="277" /> <h3><strong>CHARLES BABBAGE’S MACHINES</strong></h3>

<h1><strong>ELECTRONIC COUNTING DEVICES AND MODERN COMPUTER</strong></h1> CONTENT <ol> <li>John Von Neumann Machine</li> <li>Modern Machines</li> </ol>   <h2><strong>JOHN VON NEUMANN’S MACHINE</strong></h2> In 1945, mathematician John von Neumann undertook a study of computation that demonstrated that a computer could have a simple, fixed structure, yet be able to execute any kind of computation given properly programmed control without the need for hardware modification. Von Neumann contributed a new understanding of how practical fast computers should be organized and built; these ideas, often referred to as <strong>the stored-program technique, became fundamental for future generations of high-speed digital computers and were universally adopted.</strong> The primary advance was the provision of a special type of machine instruction called conditional control transfer which permitted the program sequence to be interrupted and reinitiated at any point, similar to the system suggested by Babbage for his analytical engine and by storing all instruction programs together with data in the same memory unit, so that, when desired, instructions could be arithmetically modified in the same way as data. Thus, data was the same as program.

<h1><strong>FIRST, SECOND, THIRD, FOURTH AND FIFTH GENERATIONS OF COMPUTERS</strong></h1> CONTENT <ol> <li>Generations of Computers</li> <li>First Generation – Vacuum Tubes (1940 – 1956)</li> <li>Second Generation – Transistors (1956 – 1963)</li> <li>Third Generation - Integrated Circuits (IC) (1964 – 1971)</li> <li>Fourth Generation - Very Large Integrated Circuits (1972 - 1984)</li> <li>Fifth Generation - Artificial Intelligence (AI) (1980s to Date)</li> </ol>   <h2><strong>Generations of Computers</strong></h2> Generation of computers is the developmental stages that the computer has gone through. There are 5 generations of computers and their accompanying innovations. <br> <h2><strong>First Generation – Vacuum Tubes (</strong><strong>1940 – 1956)</strong></h2> First generation computers were those manufactured between 1940s and 1950s. The computers used the stored program concept. First generation computers were associated with the vacuum tubes or valves technology as circuitry and magnetic drums for memory. <h3><strong>Characteristics of the First Generation of Computers</strong></h3> <ol> <li>They were very bulky and heavy.</li> <li>They measured between 50 – 100ft long and about 80ft high.</li> <li>The computers weighed up to 200 tons and occupied 3000 cubic ft.</li> <li>They used vacuum tubes to store and process data.</li> <li>Examples of first generation computers are ENIAC, EDSAC, and UNIVAC.</li> <li>It generates a lot of heat</li> <li>It relies on machine language</li> <li>These computers were limited to solving one problem at a time</li> </ol> <h3><strong>Problems of First Generation of Computers</strong></h3>

<h1><strong>DATA PROCESSING</strong></h1> CONTENT <ol> <li>Definition of Data Processing</li> <li>Data Processing Cycle</li> </ol>   <h2><strong>Definition of Data Processing</strong></h2> Data processing is the process of producing meaningful information by collecting all items of data together and performing operations on them to extract information. Data processing can also be described as a series of actions or operations that convert or manipulate data into useful information. Data processing involves the systematic recording, calculation, selection and combination of data to obtain facts and disseminate facts in relation to events in our everyday life. The processing of data can either be done manually or with the use of electronic machines. Data processing can involve calculating, sorting, editing etc.   <h2><strong>Data Processing Cycle</strong></h2> Data processing cycle includes the following: