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IT2221 THE EVERCHANGING COMPUTERS Analog Computers The Evolution of Computers...

IT2221 THE EVERCHANGING COMPUTERS Analog Computers The Evolution of Computers James Thomson A computer is a programmable computing device that can process, He did the early foundational work on analog computation in the 19th store, and retrieve data. The computer data is processed according to century. He invented a wheel and a disc integrator used in mechanical the software's instructions or commands. Computers play an integral analog devices. He then worked with his brother Lord Kelvin to create part in modern society by transforming the modern world into a global a device that integrates a product of two functions. village. Kelvin then detailed a general-purpose analog machine for integrating History of Computer linear differential equations of any sequence. He also built a tide- predicting analog computer used at the Port of Liverpool until the The term “computer” originates as a word referring to someone who 1960s. Tide-predicting machines are used to forecast tide patterns manually carried out calculations instead of an actual machine. and their unsteady height variations. The 1940s and 1950s Vannevar Bush Large machines consisting of thousands of vacuum tubes were part He developed the first large-scale, general-purpose analog computer of the early digital computers built in this period. These typically filled called the “Differential Analyzer.” This machine took up a large table an entire room, but the computational power was only a fraction of the and weighed 100 tons, allowing integration and differential equation functions of personal computers today. problems to be quickly resolved. The two distinct families of computing devices are digital computers The Differential Analyzer also contained wheels, discs, shafts, and and historical analog computers. gears to execute calculations and required a considerable set-up time by technicians to solve equations. It contained up to 150 motors and Digital Computers – a sequential device that operates data lengthy wires connecting relays and vacuum tubes. one at a time. The data are represented in the binary format of “0” and “1”; a single transistor is used to symbolize a binary Although the data representation in an analog computer is compact, it digit. is constantly subjected to noise corruption. A single capacitor can symbolize one continuous variable in an analog computer, whereas Analog Computers: The representation of data reflects the various transistors are needed in a digital computer. properties of the data being modeled in an analog computer. For example, data and numbers may be represented by Analog computers were phased out shortly after World War II. physical quantities such as electric voltage, whereas digital computers use a stream of binary digits to represent them. 03 Handout 1 *Property of STI  [email protected] Page 1 of 5  IT2221 Digital Computers Integrated Circuits (Third Generation) Vacuum Tubes (First Generation) Jack Kilby of Texas Instruments invented the integrated circuit in 1958. These consists of a set of electronic circuits on a small chip of These devices depended on the flow of electric current through a semiconductor material smaller than a circuit made of independent vacuum. Vacuum tubes were widely used in electronic devices such components. as televisions, radios, and computers until the invention of transistors. His idea to properly engineer a piece of germanium to act as several The first generation of computers used thousands of bulky vacuum components simultaneously led to the birth of the first integrated tubes, with several racks taking up an entire room. The vacuum tube circuit. Its progress involved resizing transistors and arranging them used in the early computers was a three-terminal device consisting of on semiconductors. The use of semiconductors led to third-generation a cathode, grid, and plate. computers, with significant advances in speed and efficiency. The first generation of digital computers used vacuum tubes. Users interacted with third-generation computers using keyboards and Examples include the Atanasoff-Berry Computer (ABC) developed in monitors and interfaced with an operating system. It allowed the 1942, Colossus in 1944, Electronic Numerical Integrator and device to process several different applications simultaneously with a Computer (ENIAC) in the mid-1940s, Universal Automatic Computer I central program that monitored the memory. Computers became (UNIVAC I) in 1951; Whirlwind in 1951; and the IBM 701 in 1953. accessible to a broader audience as they became smaller and cheaper. Transistors (Second Generation) Microprocessors (Fourth Generation) The transistor is the fundamental building block in modern electronic systems for revolutionizing the field of electronics. Compared to The Intel P4004 1969 microprocessor was the world’s first vacuum tubes, transistors were much smaller, cheaper, and more microprocessor. It was the first semiconductor device that provided reliable based on functionality. the functions of a computer at a chip level. It provided the basic building blocks for today’s microcomputers, including the arithmetic- A transistor is a three-terminal, solid-state electronic device that can logic unit (ALU) and the control unit. control electric current or voltage between two terminals. It is achieved by applying an electric current or voltage to the third terminal. A three- The rise of microprocessors led to the fourth generation of computers terminal transistor allows an electric switch to be created, which can with thousands of integrated circuits placed onto a single silicon chip. be controlled by another electrical switch. A single chip could contain components of a computer from the control processing unit (CPU) and memory to input and output controls. The second generation of computers used transistors instead of Microprocessors could fit in the palm, whereas first-generation vacuum tubes, most evidently by the experiments by the University of computers filled an entire room. Manchester. The result of their experiment on the transistor computer was one of the earliest transistor computers whose prototype machine All computers consist of two basic parts: hardware and software. The appeared in 1953, with the full-size version commissioned in 1955. hardware is the physical part of the machine, while the software is a set of instructions that commands the computer what to do. 03 Handout 1 *Property of STI  [email protected] Page 2 of 5  IT2221 Key Components of Computers b. Control Unit: This manages the computer device functions and is the central component of the CPU. A computer system is not just a single device operating independently. It consists of various components with specific functions and features Once the data is in the memory, it processes it for execution. to support the entire system. These components are divided into three It is where the data conversion from human language to key components: Input Unit, Output Unit, and Central Processing machine language occurs as it interprets the signal and sends Unit (CPU) – which is further divided into the memory unit, control it over to the output unit. unit, and arithmetic-logic unit (ALU). This unit maintains a data flow inside the system and transfers Input Unit the commands to the arithmetic-logic unit. A computer system responds to the instructions it receives from the c. Arithmetic-Logical Unit (ALU): This processor is users and uses an input unit to acquire those instructions. Input units responsible for mathematical calculations and issues the take user commands in the form of data and convert them into a digital computer system deals with while functioning. It is also used language format sent to the processing unit for the next step. for data comparison and decision-making. Examples of input units include a keyboard, mouse, scanner, joystick, It has features to accomplish different mathematical solutions and trackball. like addition, subtraction, and multiplication, but it only performs the calculation when necessary and then sends it to Central Processing Unit (CPU) the output unit. The data from the input unit proceeds to the processing unit before it Output Unit is executed. CPU understands the command and how it can be achieved. It converts the data accepted in human language into When the input and central processing unit processes are machine language for computers to interpret. accomplished, the data is fed to the output unit, where the result is shown. These devices always connect to the system, thus making The CPU has three (3) main components: coordination easier. a. Memory Unit: When data reaches the processor from input A computer monitor is one of the primary output devices that displays devices, the memory unit saves it immediately. It has pre- the results to the user. Other examples include printers, projectors, existing programs that transmit the data to the other parts of speakers, headphones, and plotters. the CPU. It is where all the information becomes available, and bits and bytes (8 bits) are used to measure data size. This unit is also responsible for storing data from input devices and storing the result data from output devices. 03 Handout 1 *Property of STI  [email protected] Page 3 of 5  IT2221 The Operating System Examples of Operating Systems Operating System (OS) – a collection of software programs and Microsoft Windows commands that control computer hardware to make it usable. It allows the computing power of the hardware available to the computer users It is a family of graphical operating systems created by Microsoft. The and manages the hardware to attain good system performance. original Windows 1.0 OS was introduced in 1985 as a graphical operating system shell to compete with Apple’s GUI OS in 1984. An operating system handles hardware such as the processors, input/output devices, communication devices, and data, and it Currently, Microsoft Windows wins the personal computer and laptop provides functionality, including hardware sharing, error recovery, and market with over 90% market share. However, Windows has not been network communication management. as successful in dominating the smartphone and tablet market. Advantages of Operating System Mac OS Abstraction – allow users to hide details of hardware by It is the desktop operating system created by Apple Inc., designed to creating an abstraction. work for Macintosh computers. Mac OS provides several different Executable Programs offer an environment where users features, such as a graphical user interface, multitasking, and memory may execute programs or applications. security. User-friendly – provides the computer system with easy-to- use format resources. Mobile Operating Systems Disadvantages of Operating System Android Volatility: Users may lose all the contents stored in the It is a mobile operating system developed by Google and the Open computer system whenever an issue occurs. Handset Alliance designed for touchscreen smartphones and tablets. Expensive: OS software is costly for small organizations, The first Android smartphone was released in late 2008, and Android which can cause an additional financial burden. remains the most widely used mobile operating system. Unpredictable: It is never secure, as threats can happen anytime. iOS It is a mobile operating system for Apple’s smartphones and tablets. It was developed from the MAC OS/X operating system in 2007. Multitasking for iOS was introduced in 2010 with the release of iOS version 4.0. 03 Handout 1 *Property of STI  [email protected] Page 4 of 5  IT2221 References: Data Flair (n.d.a.). Components of a computer and their functions. [Web Article]. Retrieved on July 5, 2022, from https://data- flair.training/blogs/computer-components-with-functions/ O’Regan, G. (2021). A brief history of computing. Springer. The Avinash Pandey (2022). 10 examples of operating systems. Web Article]. Retrieved on July 5, 2022, from https://quicklearncomputer.com/examples-of-operating-system- types-of-operating-system 03 Handout 1 *Property of STI  [email protected] Page 5 of 5