Basic Computing Concepts PDF

**MODULE 1** **Basic Computing Concepts** A **computer** can be described as an electronic device that accepts data as input, processes the data based on a set of predefined instructions called program to produce the result of these operations as output called information. From this description, a...

**MODULE 1** **Basic Computing Concepts** A **computer** can be described as an electronic device that accepts data as input, processes the data based on a set of predefined instructions called program to produce the result of these operations as output called information. From this description, a computer can be referred to as an Input-Process-Output (IPO) system, pictorially represented in the Figure 1: Figure 1.1: IPO Representation of a computer System **Data** are raw facts, such as a score in examination or the name of a student, for example 55 or Malik respectively. There are three types of data -- Numeric, alphabetic, and alphanumeric. Numeric data consists of digits 0 -- 9 (such as 31), while alphabetic data consist of any of the English language alphabets in upper and lower cases (e. g. Toyin). An alphanumeric data can consist of a number, an alphabet or a special character, such as a vehicle plate number (e. g. AE 731 LRN). **Information:** data as described above contain no meaning, however, when it is transformed into a more meaningful and useful form, it is called **information**. The transformation process involves a series of operations to be performed by the computer on the raw data that are fed into the system. The operation can be arithmetic (such as addition, subtraction, multiplication, and division), logical comparison or character manipulation (as in text processing). **Logical** comparison means testing whether one data item is greater than, equal to, or less than another item, and based on the outcome of the comparison, a specified action can be taken. The output of the processing can be in form of reports which can be displayed or printed. **The History of Computer** In the early days of man, fingers and toes were used for counting. Later on, sticks and pebbles were used. Permanent records of the result of counting were kept by putting marks on the ground, wall and so on using charcoal, chalk, and plant juice. The historical development of computing focuses on the digital computer from the **Abacus** to the modern **electronic computer**. Some of these people whose contributions have been widely acknowledged to the development of Computer will be discussed: **Abacus** The abacus was invented to replace the old methods of counting. It is an instrument known to have been used for counting as far back as 500 B.C. in Europe, China, Japan and India and it is still being used in some parts of China today. The abacus qualifies as a digital instrument because it uses beads as counter to calculate in discrete form. It is made of a board that consists of beads that slide on wires. The abacus is divided by a wooden bar or rod into two zones. Perpendiculars to this rod are wires arranged in parallel, each one representing a positional value. Each zone is divided into two levels - upper and lower. Two beads are arranged on each wire in the upper zone, while five beads are arranged on each wire in the lower zone. The abacus can be used to perform arithmetic operations such as addition and subtraction efficiently. **Note that the abacus is really just a representation of the human fingers: the 5 lower rings on each rod represent the 5 fingers and the 2 upper rings represent the 2 hands.** **Blaise Pascal** Pascal was born at Clermont, France in 1623 and died in Paris in 1662. Pascal was a Scientist as well as a Philosopher. He started to build his mechanical machine in 1640 to aid his father in calculating taxes. He completed the first model of his machine in 1642 and it was presented to the public in 1645. The machine, called Pascal machine or Pascaline, was a small box with eight dials that resembled the analog telephone dials. Each dial is linked to rotating wheel that displayed the digits in a register window. Pascal's main innovative idea was the linkage provided for the wheels such that an arrangement was made for a carry from one wheel to its left neigbour when the wheel passed from a display of 9 to 0. The machine could add and subtract directly.  Figure 1.3: Pascal\'s Pascaline \[photo © 2002 IEEE\] **A Pascaline opened up so you can observe the gears and cylinders which rotated to display the numerical result** **Joseph Marie Jacquard** In 1801 the Frenchman Joseph Marie Jacquard invented a power loom that could base its weave (and hence the design on the fabric) upon a pattern automatically read from punched wooden cards, held together in a long row by rope. Descendents of these ***punched cards*** have been in use ever since. Figure 1.4: Jacquard\'s Loom showing the threads and the punched cards  **Figure 1.5:By selecting particular cards for Jacquard\'s loom you defined the woven pattern \[photo © 2002 IEEE\]** **Charles Babbage** Charles Babbage was born in Totnes, Devonshire on December 26, 1792 and died in London on October 18, 1871. He was educated at Cambridge University where he studied Mathematics. In 1828, he was appointed Lucasian Professor at Cambridge. Charles Babbage started work on his analytic engine when he was a student. His objective was to build a program-controlled, mechanical, digital computer incorporating a complete arithmetic unit, store, punched card input and a printing mechanism. The program was to be provided by the set of Jacquard cards. However, Babbage was unable to complete the implementation of his machine because the technology available at his time was not adequate to see him through. Moreover, he did not plan to use electricity in his design. It is noteworthy that Babbage's design features are very close to the design of the modern computer. Babbage invented the modern postal system, cowcatchers on trains, and the ophthalmoscope, which is still used today to treat the eye. ***Augusta Ada Byron*** Ada Byron was the daughter of the famous poet Lord Byron and a friend of Charles Babbage, (Ada later become the Countess Lady Lovelace by marriage). Though she was only 19, she was fascinated by Babbage\'s ideas and through letters and meetings with Babbage she learned enough about the design of the Analytic Engine to begin fashioning programs for the still unbuilt machine. While Babbage refused to publish his knowledge for another 30 years, Ada wrote a series of \"Notes\" wherein she detailed sequences of instructions she had prepared for the Analytic Engine. The Analytic Engine remained unbuilt but Ada earned her spot in history as the first computer programmer. Ada invented the subroutine and was the first to recognize the importance of looping. **Herman Hollerith** Hollerith was born at Buffalo, New York in 1860 and died at Washington in 1929. Hollerith founded a company which merged with two other companies to form the Computing Tabulating Recording Company which in 1924 changed its name to International Business Machine (IBM) Corporation, a leading company in the manufacturing and sales of computer today. Hollerith, while working at the Census Department in the United States of America became convinced that a machine based on cards can assist in the purely mechanical work of tabulating population and similar statistics was feasible. He left the Census in 1882 to start work on the Punch Card Machine which is also called Hollerith desks. This machine system consisted of a punch, a tabulator with a large number of clock-like counters and a simple electrically activated sorting box for classifying data in accordance with values punched on the card. The principle he used was simply to represent logical and numerical data in the form of holes on cards. His system was installed in 1889 in the United States Army to handle Army Medical statistics. He was asked to install his machine to process the 1890 Census in USA. This he did and in two years, the processing of the census data was completed which used to take ten years. Hollerith's machine was used in other countries such as Austria, Canada, Italy, Norway and Russia.  **Figure 1.7: Hollerith desks \[photo courtesy The Computer Museum** **John Von Neumann** Von Neumann was born on December 28, 1903 in Budapest, Hungary and died in Washington D. C. on February 8, 1957. He was a great mathematician with significant contribution to the theory of games and strategy, set theory and the design of high speed computing machines. In 1933, he was appointed one of the first six professors of the school of mathematics in the institute for Advanced Study at the Princeton University, USA, a position he retained until his death. Neumann with some other people presented a paper titled "The Preliminary discussion of the Logical Design of an Electronic Computing Instrument" popularly known as Von Neumann machine. This paper contains revolutionary ideas on which the present-day computers are based. The machine has Storage, Control, Arithmetic and input/output units. The machine was to be a general-purpose computing machine. It was to be an electronic machine and introduced the concept of stored program. This concept implied that the operations in the computer were to be controlled by a program stored in the memory of the computer. This program was to consist of codes that intermixed data with instructions. As a result of this, it became possible for computations to proceed at electronic speed, perform the same set of operations or instructions repeatedly and the concept of program counter, which implied that whenever an instruction is fetched, the program counter which is a high-speed register automatically contains the address of the instruction to be executed next. ***J. V. Atanasoff*** One of the earliest attempts to build an all-electronic digital computer occurred in 1937 by ***J. V. Atanasoff***, a professor of physics and mathematics at Iowa State University. By 1941 he and his graduate student, Clifford Berry, had succeeded in building a machine that could solve 29 simultaneous equations with 29 unknowns. This machine was the first to store data as a charge on a capacitor, which is how today computers stored information is in their main memory. It was also the first to employ binary arithmetic. However, the machine was not programmable, it lacked a conditional branch, its design was appropriate for only one type of mathematical problem, and it was not further pursued after World War II. ***Howard Aiken*** ***Howard Aiken*** of Harvard was the principal designer of the Mark I. The Harvard ***Mark I*** computer was built as a partnership between Harvard and IBM in 1944. This was the first programmable digital computer made in the U.S. But it was not a purely electronic computer. Instead the Mark I was constructed out of switches, relays, rotating shafts, and clutches. The machine weighed 5 tons, incorporated 500 miles of wire, was 8 feet tall and 51 feet long, and had a 50ft rotating shaft running its length, turned by a 5 horsepower electric motor. The Mark I ran non-stop for 15 years.  ***Grace Hopper*** ***Grace Hopper*** was one of the primary programmers for the Mark I. Hopper found the first computer \"bug\": a dead moth that had gotten into the Mark I and whose wings were blocking the reading of the holes in the paper tape. The word \"bug\" had been used to describe a defect since at least 1889 but Hopper is credited with coining the word \"debugging\" to describe the work to eliminate program faults. 3. In 1953 Grace Hopper invented the first high-level language, \"Flow-matic\". This language eventually became COBOL which was the language most affected by the infamous Y2K problem. A high-level language is designed to be more understandable by humans than is the binary language understood by the computing machinery. A high-level language is worthless without a program \-- known as a ***compiler*** \-- to translate it into the binary language of the computer and hence Grace Hopper also constructed the world\'s first compiler. Grace remained active as a Rear Admiral in the Navy Reserves until she was 79. **Bill Gates** William (Bill) H. Gates was born on October 28, 1955 in Seattle, Washington, USA. ***Bill Gates*** decided to drop out of college so he could concentrate all his time writing programs for Intel 8080 categories of Personal Computers (PC). This early experience put Bill Gates in the right place at the right time once IBM decided to standardize on the Intel microprocessors for their line of PCs in 1981. Gates founded a company called Microsoft Corporation (together with Paul G. Allen) and released its first operating system called MS-DOS 1.0 in August, 1981 and the last of its group in (MS-DOS 6.22) April, 1994. Bill Gates announced Microsoft Windows on November 10, 1983. **Philip Emeagwali** Philip Emeagwali was born in 1954, in the Eastern part of Nigeria. He had to leave school because his parents couldn\'t pay the fees and he lived in a refugee camp during the civil war. He won a scholarship to university. He later migrated to the United States of America. In 1989, he invented the formula that used 65,000 separate computer processors to perform 3.1 billion calculations per second. Philip Emeagwali, a supercomputer and Internet pioneer is regarded as one of the fathers of the internet because he invented an international network which is similar to, but predates that of the Internet. He also discovered mathematical equations that enable the petroleum industry to recover more oil. Emeagwali won the 1989 Gordon Bell Prize, computation\'s Nobel Prize, for inventing a formula that lets computers perform the fastest computations, a work that led to the reinvention of supercomputers.