Mohammad Qasim Khan Lecturer Department of Computer Science, AIOU

1. Mohammad Qasim Khan Lecturer Department of Computer Science, AIOU

2. History of Computer • The abacus is often wrongly attributed to China. In fact, the oldest surviving abacus was used in 300 B.C. by the Babylonians. • The abacus is still in use today, principally in the far east. • A modern abacus consists of rings that slide over rods, but the older one pictured below dates from the time when pebbles were used for counting (the word "calculus" comes from the Latin word for pebble).

3. History of Computer …..cont • In 1617 an eccentric (some say mad) Scotsman named John Napier invented logarithms, which are a technology that allows multiplication to be performed via addition. • The magic ingredient is the logarithm of each operand, which was originally obtained from a printed table. • Napier also invented an alternative to tables, where the logarithm values were carved on ivory sticks which are now called Napier's Bones.

4. History of Computer …..cont • Napier's invention led directly to the slide rule, first built in England in 1632 . • Still in use in the 1960's by the NASA engineers of the Mercury, Gemini, and Apollo programs which landed men on the moon.

5. History of Computer …..cont • The first gear-driven calculating machine to actually be built was probably the calculating clock, so named by its inventor, the German professor Wilhelm Schickard in 1623.

6. History of Computer …..cont • In 1642 Blaise Pascal, at age 19, invented the Pascaline as an aid for his father who was a tax collector. • Pascal built 50 of this gear-driven one-function calculator (it could only add) but couldn't sell many because of their exorbitant cost and because they really weren't that accurate (at that time it was not possible to fabricate gears with the required precision).

7. History of Computer …..cont • 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 (remember the "hanging chad" from the Florida presidential ballots of the year 2000?).

8. History of Computer …..cont • By 1822 the English mathematician Charles Babbage was proposing a steam driven calculating machine the size of a room, which he called the Difference Engine. • This machine would be able to compute tables of numbers, such as logarithm tables. • He obtained government funding for this project due to the importance of numeric tables in ocean navigation.

9. History of Computer …..cont • Harvard Mark I computer which 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 50 ft rotating shaft running its length, turned by a 5 horsepower electric motor.

10. History of Computer …..cont • home computer of 1976 such as this Apple I which sold for only $600

11. History of Computer …..cont • One of the earliest attempts to build an all-electronic (that is, no gears, cams, belts, shafts, etc.) digital computer occurred in 1937 by J. V. Atanasoff, a professor of physics and mathematics at Iowa State University.

12. History of Computer …..cont • University students in the 1970's bought blank cards a linear foot at a time from the university bookstore. Each card could hold only 1 program statement. To submit your program to the mainframe, you placed your stack of cards in the hopper of a card reader. • By the 1990's a university student would typically own his own computer and have exclusive use of it in his dorm room. • the first microprocessor was developed at Intel in 1971.

13. History of Computer …..cont • In the 1980’s, very large scale integration (VLSI), in which hundreds of thousands of transistors were placed on a single chip, became more and more common. • Many companies, some new to the computer field, introduced in the 1970s programmable minicomputers supplied with software packages.

14. History of Computer …..cont • By the late 1980s, some personal computers were run by microprocessors that, handling 32 bits of data at a time, could process about 4,000,000 instructions per second. • Microprocessors equipped with read-only memory (ROM), which stores constantly used, unchanging programs, now performed an increased number of process-control, testing, monitoring, and diagnosing functions, like automobile ignition systems, automobile-engine diagnosis, and production-line inspection duties.

15. Types of Computers • Personal computers or microcomputers • Desktop computers • Laptop and notebook computers • Tablet PC • Palmtop computers • Personal digital assistants (more commonly known as PDA's) • Programmable calculator • Mini Computers • Mainframe Computers

16. Computer Organization • A closely related term, computer architecture, emphasizes the engineering decisions and tradeoffs that must be made in order to produce a "good" design. The computer architect answers questions like... • How many registers should there be? • What machine instructions should there be? • How should the cache be organized? • What hardware support should there be for virtual memory?

17. Computer Virus • Computer viruses are programs written by people. • These virus programs are placed into a commonly used program so that program will run the attached virus program as it boots, therefore, it is said that the virus "infects" the executable file or program.

18. Computer Bus • Buses in computers. Buses are the basic transportation lines for moving data, instructions, addresses, and other information inside a computer. • A bus, in computing, is a set of physical connections (cables, printed circuits, etc.) which can be shared by multiple hardware components in order to communicate with one another. • The purpose of buses is to reduce the number of "pathways" needed for communication between the components, by carrying out all communications over a single data channel. • This is why the metaphor of a "data highway" is sometimes used.

19. Computer Port • computer and telecommunication devices, a port (noun) is generally a specific place for being physically connected to some other device, usually with a socket and plug of some kind. • Typically, a personal computer is provided with one or more serial ports and usually one parallel port. • The serial port supports sequential, one bit-at-a-time transmission to peripheral devices such as scanners and the parallel port supports multiple-bit-at-a-time transmission to devices such as printers.

20. Processor’s Word Size • The number of bits that a CPU can process at one time. Processors with many different word sizes have existed though powers of two (8, 16, 32, 64) have predominated for many years. • A processor's word size is often equal to the width of its external data bus though sometimes the bus is made narrower than the CPU (often half as many bits) to economize on packaging and circuit board costs. • The size of a word is reflected in many aspects of a computer's structure and operation. The majority of the registers in the computer are usually word-sized. • The typical numeric value manipulated by the computer is probably word sized. • The amount of data transferred between the processing part of the computer and the memory system is most often a word. An address used to designate a location in memory often fits in a word. • Some of the earliest computers were decimal rather than binary, typically having a word size of 10 or 12 decimal digits, and some early computers had no fixed word length at all.

21. RAM Capacity • RAM is an abbreviation for Random Access Memory. • It usually refers to "temporary" memory, as when the system is shut down, the memory is lost. • This is why the memory is referred to as being "random," as any piece of information can be circulated through the memory regardless of its location and its relation to any other information within the RAM. • Its unit is Bit (a unit area for storing data like 0 or 1 on magnetic core of the media chip. • Bit, Byte, MB, GB, TB, Penta Byte, and Exa Byte.

22. Data processing Techniques • This is defined as the process of converting data to usable information. • Surveying for the creation of Pattern. • Classification of different patterns. • Structures of various information. • Data processing technique is term used for specific data processing in desire format. • Data acquisition • Data entry • Data cleaning • Data coding • Data transformation • Data translation • Data summarization • Data aggregation • Data validation • Data tabulation • Statistical analysis • Computer graphics • Data warehousing • Data mining