What is Information??? • Opinion • Science • Knowledge
Going to the cinema; • Hours • Tranportation • Costs • Films • Possible Seats????
How can we learn them? • Newspapers • Magazines • Asking to someone else • Internet • Phone …..etc.
Information technology is... • IT refers to the role of technology in gathering and using information • Information is an increasingly important resource for businesses and individuals • Computer and communications technologies are more powerful, flexible and cheaper than ever before
How can we learn them? • Newspapers • Magazines • Think that we don’t know how to read-write? • Internet • Think that we don’t know how to use computers? • Asking to someone else • Phone …..etc. • Think that we don’t know the speaken language?
IT is; • All the technologies that we talked about and all the knowledge to use them. • The main purpose is to know much to make better decisions.
Information systems - examples • The spreadsheet I use to record BİL158 marks • An expert system used to diagnose car faults • An executive information system that summarises the state of the business and compares with competitors • A supermarket’s stock control system
Information systems • System (usually computerised) that helps an organisation carry out its tasks and achieve its goals • An Information System is a set of interrated parts that work together to produce, distribute, and use information products. • Components: • hardware • software • data / information • people • procedures
What computers do • A computer has just four basic operations: • receive data as input from the outside world • process this data • output useful information to the outside world • store data and information for further use • It processes raw data to make useful information. But it can perform these operations very fast, accurately and reliably, and can store huge amounts of information
Hardware • Hardware consists of: • input devices • output devices • processing (the CPU and main memory) • storage • communications hardware
Software • Software (programs) is what makes the computer a general purpose tool - changing the software changes the function • Applications software - useful to the user eg. Word XP, games, a payroll system • Systems software - needed to ‘run’ the computer eg. Windows XP, Macintosh OS, anti-virus programs
People - the most important part of an information system • Customers - ultimate users of the information system • Workers and managers - use the information system to carry out their tasks • Systems personnel - ensure the system runs effectively on a day-to-day basis • Systems analysts/programmers - design and develop the information system • End user developers
Evolution of computers and communication technology • Institutional computing era (1950- ) • large expensive systems for basic organisational tasks • Personal computing era (1975- ) • small, cheap desktop computers for personal use • Today - interpersonal computing (1995- ) • networks of interconnected computers, the Internet and World Wide Web
Categories of computers • Mainframes and supercomputers • large organisations: banks, airlines etc • powerful ‘number crunching’ for research • many users, connected via terminals enabling ‘timesharing’ • servers provide software and other resources to networked computers • Hence ‘enterprise’ server
Categories of computers • Personal computers and workstations • single user, for personal productivity • often networked • Workstations may be used as mid-range servers
Categories of computers • Portable computers • laptops, notebooks, personal digital assistants (PDAs) in the form of palmtop and handheld computers • Embedded computers • cars, microwave ovens, etc; sensors and control systems • are single-purpose, not general purpose
Trends - hardware • Faster, smaller, more powerful processors • More direct, easier to use input and output devices • Larger storage capacity • Faster, wider bandwidth communications media to transmit more information • Linking computers together in networks - local area networks, wide area networks, the Internet
Trends - software • Easy to use software, integration of different tools • Multimedia is widespread • System development is moving from the hands of the professionals to the end user • Use of artificial intelligence
Trends - social • the threat to personal privacy • the hazards of high-tech crime and the difficulty of keeping data secure • the difficulty of defining and protecting intellectual property • the risks of failure of computer systems • the dangers of dependence on complex technology
COMPUTER FACTS • A computer is an electronic device which works within a binary digital system and has 4 functions: • Accept input (data – isolated facts) • Process input (data) • Produce output (information – processed data) • Storage
printer Hard Drive BUS Tower CPU RAM Floppy CD Drive Drive Ports Peripheral devices keyboard mouse Monitor
We call this box by several names: Computer Tower Desktop This box contains: CPU Drives System board Slots Interface cards Power Supply Ribbons, connections, etc. System unit (box)
Computer (System Unit) Switch Reset Button
The Back of a Computer • This is where devices are “plugged” into the computer: • mouse • keyboard • printer • internet connection • monitor • etc.
Front Panel • The front has been removed to show: • switches • floppy • CD drive
Power Supply • The power supply reduces house current to smaller voltages (5 and 12 V.) • Notice the many wires protruding from the back of the power supply • These wires provide current for the various parts of the computer
System Board • Also called the mainboard • Has slots for cards, rams and cpu. • Devices are connected to mainboard • With the ways on it transfer data from one place to another.
CPU (Central Processing Unit) • Controls the system • Performs mathematical operations • Logic is performed here • Has a cooling fan attached cause temperature is important
Memory... • ROM (Read Only Memory) • PROM • EPROM • EEPROM • RAM(Random Access Memory) • DRAM • SRAM
ROM(Read Only Memory) • Programs written once and can be read many(Power source is NOT important) • Holds BIOS programme • PROM (Programmable chip with a programming device) • EPROM(Can be programmed with light) • EEPROM(Programmed by power source)
RAM Storage Units Random Access Memory
KILOBYTE MEGABYTE GIGABYTE TERABYTE BYTE = smallest unit of storage binary digit; 1 or a 0 BIT = 8 bits = 1,000 bytes = 1,000,000 bytes = 1,000,000,000 bytes = 1,000,000,000,000 bytes
RAM FACTS • Holds data and instructions waiting for processing by the CPU • Temporary storage • Contents are deleted when power source removed.
DRAM • Is used memory in the computers • EDODRAM • SDRAM • DDRRAM are the kinds...
SRAM • Main difference from DRAM is no need to update the data • Included in CPU nowadays • Costs more than DRAM • So it is used for cache
CACHE • Cache is fast accessing intermediate memory that holds the most needed data and instructions. • It is smaller than RAM. • Because it is smaller than RAM a search of cache is faster memory access. • Therefore it is always searched first when available.
How does the data flow? CPU CACHE RAM HDD
All secondary storage has 2 parts: A disk – a platter which stores the data/inforamtion A drive – mechanism which reads the disk NOTE: a read/write head is part of the drive which sits over the disk and read the data
All Disks have two parts: SECTORS TRACKS
All Disks have two parts: This makes an Addressable Space. Therefore, Disks are Randomly Accessible.
Hard Drives • Composed of several disks. • Very large, permanent storage. • Not portable storage. • Disks are magnetic.
Floppy Drives • Composed of one disk. • Small storage.(Max. 1,44 MB) • Portable storage. • Disks are magnetic.