<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.