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• A computer is an electronic device that accepts data as input, processes it based on a set of predefined instructions (program), and produces output called information; can be referred to as an Input-Process-Output (IPO) system.
• Raw facts, like a student's exam score or name, are considered data (e.g., 55 or Malik).
• Data can be numeric (digits 0-9, e.g., 31), alphabetic (English letters, e.g., Toyin), or alphanumeric (numbers, letters, special characters, e.g., AE731LRN).
• Information is data transformed into a meaningful and useful form through operations like arithmetic, logical comparison, or character manipulation.
• Logical comparison involves testing if one data item is greater than, equal to, or less than another, resulting in a specified action, and the output can be displayed or printed as reports.

History of Computers

• In early times, people counted using fingers and toes, then sticks and pebbles; permanent records were made by marking on the ground, walls, or with charcoal/chalk/plant juice.
• The historical development of computing is focused on the evolution of the digital computer.

Abacus

• This instrument was invented to replace older counting methods.
• It was has been used since 500 B.C. in Europe, China, Japan, and India, and is still used in China today.
• It qualifies as a digital instrument because it accounts incrementally using beads on wires divided into two zones by a bar. The wires are arranged in parallel, each wire is assigned a positional value.
• Each zone is further divided into upper and lower levels.
• The upper zone is arranged with two beads on each wire, and the lower zone has five beads arranged on each wire.
• Arithmetic operations such as addition and subtraction can be performed efficiently using this.
• The abacus represents human fingers: the 5 lower rings representing the 5 fingers, and the 2 upper rings representing the 2 hands.

Blaise Pascal

• Pascal was born in Clermont, France in 1623 and died in Paris in 1662.
• He started building his machine in 1640 to calculate taxes for his father.
• He completed and presented the first model of his machine in 1642 and 1645 respectively.
• His machine, called Pascaline, was a small box with eight telephone-like dials linked to rotating wheels displaying digits in register windows.
• His innovation was the linkage between the wheels, which enabled carry-over from one wheel to its neighbor when passing from 9 to 0, allowing direct addition and subtraction.

Joseph Marie Jacquard

• In 1801, he invented a power loom that automated fabric design using punched wooden cards linked by rope. Descendants of these cards are still in use.

Charles Babbage

• Babbage was born in Totnes, Devonshire, on December 26, 1792, and died in London on October 18, 1871
• In 1828, he was appointed Lucasian Professor at Cambridge where he also studied mathematics.
• He started working on his program-controlled, mechanical, digital "Analytic Engine" computer as a student, incorporating an arithmetic unit, store, punched card input, and printing mechanism.
• The program was to be provided by Jacquard cards.
• The machine could not be completed at the time.
• The machine design was similar to modern computers.
• He is credited with inventing the modern postal system, cow catchers on trains, and the ophthalmoscope.

Augusta Ada Byron

• Ada was the daughter of Lord Byron and friend of Charles Babbage, later becoming Countess Lady Lovelace through marriage.
• She was fascinated with Babbage's Analytic Engine at 19 years old.
• She developed sequences of instructions ("Notes") for the unbuilt Analytic Engine, earning her the title of first computer programmer.
• Ada is credited with inventing the subroutine and recognizing the importance of looping in programming.

Herman Hollerith

• Hollerith was born in Buffalo, New York, in 1860, and died in Washington in 1929.
• Hollerith founded a company that merged into Computing Tabulating Recording Company, renamed International Business Machines (IBM) in 1924.
• He created a machine based on cards to assist with tabulating population and similar statistics.
• This Machine System was comprised of a punch, a tabulator with clock-like counters, and an electrically activated sorting box for data classification.
• Hollerith's system was installed in 1889 to handle Army medical statistics and in 1890 to processed census data in two years instead of ten.
• His machine was used in other countries like Austria, Canada, Italy, Norway, and Russia.

John Von Neumann

• Von Neumann was born in Budapest, Hungary on December 28, 1903; died in Washington D.C. on February 8, 1957.
• He made significant contributions to the theory of games, set theory, and the design of high-speed computing machines.
• In 1933, appointed as one of the first professors at the Institute for Advanced Study at Princeton University.
• He presented revolutionary ideas in his paper "The Preliminary Discussion of the Logical Design of an Electronic Computing Instrument," known as the Von Neumann machine.
• The paper outlined the present-day computer design principles for storage, control, arithmetic, and input/output units.
• The machine used stored program and operations controlled by a program stored in the memory of the computer.
• Computation could proceed at electronic speed, perform operations repeatedly, and use a program counter to automatically contain the address of the next instruction.

J.V. Atanasoff

• In 1937, Atanasoff attempted to build an all-electronic digital computer
• He created a machine with Clifford Berry in 1941 that could solve 29 simultaneous equations with 29 unknowns.
• It was the was the first machine to store data as a charge on a capacitor, employing binary arithmetic.
• That machine was not programmable, lacked conditional branching, and was not pursued further after WWII.

Howard Aiken

• Aiken was the designer of the Harvard Mark I.
• The Harvard Mark I computer was made as a partnership between Harvard and IBM in 1944.
• It was the first programmable digital computer made in the U.S., constructed from switches, relays, rotating shafts, and clutches, not purely electronic.
• The machine weighed 5 tons, used 500 miles of wire, was 8 feet tall and 51 feet long, and had a 50 ft rotating shaft powered by a 5-horsepower electric motor; the Mark I ran non-stop for 15 years.

Grace Hopper

• Hopper was one of the primary programmers for the Mark I.
• Hopper found the first computer "bug": a moth blocking the reading of the holes in the paper tape.
• While the term "bug" had been used for defects since 1889, Hopper is credited with coining "debugging" to describe the work to eliminate program faults.
• In 1953, Hopper invented the high-level language "Flow-matic", later evolving into COBOL and was affected by the Y2K problem.
• She also created the first compiler.

Bill Gates

• Gates was born in Seattle, Washington, USA, on October 28, 1955.
• Gates dropped out of college to focus on programming for Intel 8080 personal computers (PC).
• He co-founded Microsoft Corporation with Paul G. Allen, releasing its first operating system, MS-DOS 1.0, in August 1981.
• He announced Microsoft Windows on November 10, 1983.

Philip Emeagwali

• Emeagwali was born in 1954 in Nigeria.
• He left school due to his parents' inability to pay fees during the civil war.
• In 1989, he invented a formula using 65,000 processors to perform 3.1 billion calculations in 1 second.
• Emeagwali is regarded as one of the fathers of the Internet and also discovered mathematical equations for enhanced oil recovery.
• Emeagwali won the 1989 Gordon Bell Prize for the fastest computer computations.