Introduction to Information Technology

CHAPTER 1 INTRODUCTION TO INFORMATION TECHNOLOGY

At the end of this topic, students must be able to: - Define the computer and information technology - Differentiate the revolution of computers - Identify first computer produced - Diffrentiate types of computers and give examples - Understand computer softwares and functions of operating systems - Identify computer hardwares - Identify and provide examples on computer storage and communication devices

Electronic device that accept data, process the data according to specified rules, produce results and store the results for future use.

• Data - Collection of unprocessed items. • Information - Processed data. • Information Technology - Methods & techniques used in information handling and retrieval by automatic means.

HISTORY OF COMPUTERS LEIBNIZ From Abascus to IPhone PASCAL ABASCUS IPHONE - Abascus is first being used for mathematical instructions “+,-,x, /” - In 1642, Blaise Pascal: first practical mechanical calculator, the Pascaline - In 1671, Gottfried Wilhelm Leibniz: advanced calculating machine and invented binary code. - In 1854, George Boole: Boolean algebra.

Generations Revolutions The First Generation (1943-1958) Vacuum tubes Second Generation (1959-1964) Transistors Third Generation (1965-1970) - smaller, faster, more reliable and consumed less electricity. Fourth Generation (1971-present) - Assembler languages or symbolic languages. Fifth Generation (the future) - Higher level languages (Fortran and Cobol). Integrated circuit (IC) - Size, powerful, smaller and cheaper - Multi-tasking Large-scale integration Very Large Scale Integration (VLSI) Microcomputer Artificial Intelligence, Expert Systems, Natural Language.

First programmable computer? • Konrad Zuse, a German Scientist, during 1936 and 1938 built the Z1. First Digital Computer? • J. Presper Eckert and John Mauchly were the first to invent “the ENIAC” at the University of Pennsylvania in 1946. It weighed almost 50 tons with 18,000 Vacuum Tubes. First commercial Computer? • The first commercial computer is Z4, by Kondrad Zuse in 1942.

4 basic types of computers: • Supercomputer • Mainframe Computer • Minicomputer • Microcomputer

• MOST powerful computers in terms of performance and data processing. • For research and exploration purposes, eg: NASA to launch space shuttles & controls. • Very expensive and very large in size. • Eg: Space Exploration, Space Exploration, Weather Forecasting, Nuclear weapons testing



• Used by large firms & government. • Process & store large amount of data. • Eg: Banks, Institutions, Insurance companies

• Also known as “Midrange Computers” for small bussiness. • Not for single use. 4 to about 200 users simultaneously. • For example, a production department use it for monitoring certain production process.

• For general usage like entertainment, education and work purposes. • Desktop computers, laptops, personal digital assistant (PDA), tablets & smartphones, Gaming consoles, Sound & Navigation systemCalculators

• set of instructions written in a computer language that solves a computational task • To carry out instructions, computer must execute a program • Program can be executed many times

• Acts as an interface between the user and the computer hardware and controls the execution of all kinds of programs. • Allow users to communicate with the computer & other software • Eg: Windows Vista or XP – Microsoft’s OS & Mac OS X – Apple’s OS

1. Starting a computer 2. Providing a user interface 3. Managing programs 4. Managing memory 5. Coordinating tasks 6. Configuring devices 7. Establishing an Internet connection 8. Monitoring performance 9. Providing file management & other utilities 10.Controlling network

• Allow user to perform maintenance-type tasks (related to managing a computer, its devices @ programs) – Some utility program: File manager, Search utility, Image viewer, Personal firewall, Uninstaller, Disk scanner, Disk defragmenter, Diagnostic utility, Backup Utility, Screen saver



Input devices – any hardware that allows users to enter data & instruction into a computer. Output device – hardware components that conveys information to one or more people.



Holds data, instructions & information for future use • Capacity – no of bytes a storage medium can hold • Writing – process of transferring data, instructions and information from memory to a storage medium • Reading – process of transferring items from a storage medium into a memory • Speed of storage devices and memory – access time measures: – Amount of time it takes a storage device to locate an item on a storage medium – Time required to deliver an item from memory to the processor

• Smaller size to hold data for a temporary period. • Found inside the computer, and they have the fastest access to data. • Examples: Cache memory and RAM.

• 2 types of memory – Volatile -> RAM (Random Access Memory), also called main memory (temporary) – Non-volatile -> ROM (Read Only Memory), flash memory & CMOS (Complementary metal–oxide–semiconductor - CMOS chips require less power )

3 basic types: i) Dynamic RAM (DRAM) Must be re-energized constantly or they lose their contents. - SDRAM (Synchronous DRAM) faster than DRAM chips - DDRSDRAM (Double Data Rate SDRAM) faster than SDRAM ii) Static RAM (SRAM) Static means : DO NOT HAVE to be re-energized as often as DRAM chips. More expensive. iii) Magnetoresistive (MRAM) Stores data using magnetic charges. Better in terms storage, consume less power, faster access time, retain contents after power remove.

• High-speed access area that can be either a reserved section of main memory or storage device. • As the microprocessor processes data, it looks first in the cache memory and if it finds the data there.

• Memory chip storing permanent data and instructions. • Data on most ROM chips cannot be modified • Other types of nonvolatile memory: -Flash Memory -CMOS

• Larger storage capacity & store data permanently. • The device can be both external and internal to a computer and includes; compact disk, USB drive, hard disk, etc

Common types of storage used with computers and is the technology that many computer hard drives use. – Floppy Disk – Hard Drive – Magnetic Strip – Tape Cassette

Another common storage is optical storage, which uses lasers and lights as its method of reading and writing data. - Blu Ray Disc - CD ROM Disc - CD-R / CD-RW Disc - DVD-R, DVD-RW Disc

Flash memory has started to replace magnetic media as it becomes cheaper as it is the more efficient and reliable solution. – USB Flash Drive/Thumb Drive – Memory Card

Storing data online and in cloud storage is becoming popular as people need to access their data from more than one device. -Cloud Storage - Network Media

Any hardware capable of transmitting data, instructions & information between sending device & receiving device • Dial-up modems • ISDN Modem – ISDN line • DSL Modem – DSL line • ISDN & DSL – external device

• Cable Modems – Broadband modem; sends & receives digital data over the cable television (CATV) • Wireless Modems • Network cards – Also known as NIC (network interface card) • Wireless Access Point – Central communications – allows computers to transfer data wirelessly • Routers – Connects multiple computers & transmit data to its correct destination – To prevent unauthorized users – built-in firewall

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