Introduction to Computers and Information Systems

BIL101E

http://www.be.itu.edu.tr/lisans/tr/BIL101/index.html http://atlas.cc.itu.edu.tr/~toros/bil101e.htm

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A Brief History of Computers and Knowledge Processing with A Short Introduction of the Computer Hardware

A Brief History of the Development of Operatings

Systems and Some Fundamental Concepts

Introduction to Unix: Fundamental Commands

Boot--up Actions and X Window

Computer Networks, Internet and TCP/IP

World Wide Web (WWW) Utilites and Web Design

Computerized Word Processing and Office Suites

TeX

: The Stradivarius Language of Word Processing and Document Preparation

Spreadsheets, StarOffice Spreadsheet, MSExcel

Database Systems, SQL and PostGreSQL

Sample SQL ApplicationsChapter

A Portable Scientific Visualization Program: GnuPlot

Octave

MuPAD: A Maple-like Public Symbolic Interpreter

Personel Computer

Hard

ware

Soft

ware

Any information a computer uses to perform a task; also, any information saved on a disk.

The physical components of a computer, including cables, the keyboard, the CPU, monitors, etc.

KeyboardMouse

Scanner...

CPUMainboard

HDD....

ScreenPrinter

Speakers...

INPUT SYSTEM OUTPUT

Keyboard and mouse.

Joystick Monitor Printer

Scanner Loudspeakers External drives

External tape station External modem

The mainboard: CPU, RAM, cache, ROM chips with BIOS and start-up programs. Chip sets (controllers). Ports, buses and expansion slots.

Drives: Hard disk(s), floppy drive(s), CD-ROM, etc.

Expansion cards: Graphics card (video adapter), network controller, SCSI controller. Sound card, video and TV card. Internal modem and ISDN card.

Peripherals Components in the central unit - the computer

Input-- Any information you put into the computer, through typing, copying files, or whatever.

Output is what you'd expect: any results that emerge from the computer, whether on screen, printed, on disk, etc.

CPU--Central Processing Unit. This is the heart of the computer. All input goes into the CPU, where all processing tasks are actually performed. Any output--printed, on screen, or on disk--comes out of the CPU.

How does a CPU work? [top]

How does a CPU work?The CPU is centrally located on the motherboard. Since the CPU carries out a large share of the work in the computer, data pass continually through it. The data come from the RAM and the units (keyboard, drives etc.). After processing, the data is send back to RAM and the units.

MotherBoard the main circuit board of a personal computer. The mainboard holds the CPU, the RAM, ROM with BIOS, and the chipset besides lots of other electronics and the expansion sockets.

Storage media

Drive letter

Floppy disks

Hard disk

DROM/DVD

A: B:

C: D: E:

F:

Drives:A drive is the name for several types of storage media. There are also storage media, which are not drives (RAM, Tape Streamers

Hard disk/hard driveA fixed permanent

storage unit containing a rigid disk (or disks) made

from metal; many computers contain built-

in hard disks. Floppy disk/diskette--A portable disk of plastic coated with chromium oxide, on which information is magnetically written, and from which that information can be read, copied, or deleted. The disk is protected by a shell or cover of some kind.

. Initialize/format: Initializing erases all information on a disk (if there is any) and prepares the disk to receive whatever information you wish to save on it.

.

.

RAM--Random Access Memory, the computer's "short term" memory in which all actions are performed. Also called "active memory," RAM is the memory your computer uses to run applications. The amount of RAM in your computer is fixed, although it can often be increased, and it is one of the two kinds of memory that dealers will use to describe a computer's capabilities. (The other is "storage" memory, or memory devoted to permanently saving information you have created. Disks use storage memory.) . ROM—Read Only Memory. It holds the instructions for starting up the computer. The content is written by the producer company during the construction of the computer. ROM in which information is saved once and can never be altered. For example, CD-ROM machines read information saved on compact disks--users can read that information, but cannot make changes. Some ROM is built into your computer to help it get started when you turn it on.

All PCs have instructions in ROM chips on the mainboard. The ROM chips are supplied by specialty software manufacturers, who make BIOS chips. Bios- Basic Input Output System. It determines Basic Input Output System. It determines what a computer can do without accessing a disk. what a computer can do without accessing a disk. For PCs BIOS contains all the code required for For PCs BIOS contains all the code required for the controlling the keyboard, display screen, disk the controlling the keyboard, display screen, disk drives, serial communications and so on.drives, serial communications and so on.

Monitor--The screen on which you see your work, whether in color, grayscale, or black-and-white. Mouse--A small tool that duplicates the movements of your hand on the computer's screen, allowing you to rearrange items, perform actions, select things, etc . Keyboard-- A computer keyboard is a device containing type-writer like keys which enables us to enter data into a computer.Alphanumeric keys which are composed of letters and numbers.Punctuation keys which contains Comma ,semicolon;Special keys which involve function keys, control keys, arrow keys, Caps Lock key.

Modem (Dialup, Null)--A device that plugs into a standard telephone jack and allows a computer to transmit and receive information over commercial telephone lines. (MOdulator-DEModulator)Ethernet Cards—The hardware which is a special card to be used for this protocol is called ethernet card.

Knowledge is something obtained, Stored and a static concept for information systems.

•Something learned and kept in mind,

•Clear perception of truth,

•Understanding gained by actual experience.

Information is a dynamic entity. Its dictionary meaning;

The communication or reception of knowledge or intelligence,

•Knowledge obtained from invetigation, study or instruction.

All numbering systems follow the same rules. Decimal System is Base 10. The base of a system refers to how many possible numbers can be in each digit position. In decimal, a single digit number is 0 through 9. In decimal, as you count up from 0, when you reach 9 and add 1 more, you have to add another digit position to the left and carry a 1 into it to get 10 (ten). Ten is a two digit decimal number. Binary System is Base 2. In binary a single digit number is 0 or 1. A binary number can be composed of 0s and 1s only. Computer can only use the electronic devices like chips, microchips which can be considered as a combination of zillions of the microscopic switches such that each switch can have only two position, closed or open. Hence, each switch can store two option knowledge which can be represented by either 0 or 1.

Counting

Octal System Base is 8 and the digital symbol are 0,1,2,3,4,5,6,7. It is used in the informatics science because of its conciseness.

Hexadecimal System To represent a binary number larger than 4 bits a different numbering system is normally used. It is called hexadecimal, or Base 16. In this system there are 16 possible numbers for each digit. For the first 10, 0 through 9, it looks like decimal. Unlike decimal, when you add 1 more to 9, you get A. So a hex A is a decimal 10. The numbers count up from A through F. Just to clarify this here is the sequence of counting in hex from 0 to where you have to add another digit position to the left... 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F.

Information Unit— To deal with the knowledge in quantitative scale we need to define units for it. The computer memories are designed to have switches which have only two options (open or closed) it is quite natural to use binary system for number representation. This means that the atom of the knowledge is a unit which can have only two options, 0 or 1. The smallest unit of the knowledge as BInary digiT. (BIT)

128 64 32 16 8 4 2 1

= Byte8 Bit

= 1 Kb1000 Byte

248

163264

128256512

1024

= 1 Mb1000 Kb

= 1 Gb1000 MB

O or1

Let's take a longer binary number 1 0 1 0 0 1 0 1. Starting at the right moving left, the first is worth 1, the next is worth 0, the next is worth 4, the next is 0, the next is 0, the next is worth 32, the next is 0, and the last is 128. Adding all these up you get decimal 165. Dividing this number up into two hex digits, you get A5. So binary 10100101, decimal 165, and hex A5 are all the same value. Using hex, the rightmost digit is worth 5, and the most significant digit is worth 160 (10 X 16), resulting in decimal 165. =(165)Decimal=(245)Octal=(A5)Hex

128-64-32-16-8-4-2-1

Please write binary number 01101001 decimal and hexadecimal system

1010 0101 5A

HomeworkFaturalaryazismalar Programs

Belgelerim Personel

Root Directory

File/document--any single item created with an application, whether it be a single chart, a five-page paper, or an entire thesis with graphics and

footnotes. Knowledge is stored in a file

Operating System: Operating System is the most important program which runs on a computer.

An operating system is a main program to be run on a general purpose machine that none of the other programs can be run without running this main program.

System--Specific pieces of software that your computer needs to run; for instance, it is the system that converts your keystrokes into letters and displays them on the monitor screen.

• An operating system performs fundamental tasks. For example, it recognizes the data entered through the keyboard, it sends output to the display screen. It also keeps track of files on the disk and recognizes the type of the file. The control of the peripheral devices like disk drives, printers, scanners is also provided by the operating system.

• The operating systems can have some of the following features:

• 1. Multiuser • 2. Multitasking • 3. Multithreading • 4. Multiprocessing • 5. Real-time

• An operating system provides a software platform for running other programs which are in fact called application programs.

• The softwares can be collected under two general groups : System Softwares and Application Softwares.

• The interaction between the user and operating system is provided by a software which is called command line interpreter.

The file system knows where files are saved. It finds and reads the relevant sectors and delivers the data to the operating system.

DOS Disk Operating System

• MSDOS is an acronym for Microsoft Disk Operating System. MSDOS was developed for the IBM compatible personal computers. It is still 16-bit operating system. It does not support multitasking and multiple users.

• After some time period, DOS was started to be considered insufficient for modern computer applications and new facilities were tried to be constructed. These efforts yielded new operating systems, that is, Windows X.Y.

Microsoft Windows

• According to some estimates the 80 % of the all personal computers is run by Windows. The remaining part is divided amongst MacOS, Linux,…. There is a decrease in its market percentage during the last ten years since the Linux concern of the people grew tremendously.

• Like the MacOS the Windows provides a GUI (Graphical User Interface). It supports virtual memory management, multitasking and support for many peripheral devices. Even for NT and 2000 the support for multiple users is not strong as much as UNIX.

• Windows 95

• This version of Microsoft Windows was released in 1995. It shows a significant advance over Windows 3.1. The most important advance is its 32-bit structure which makes the operating system faster.

• Windows 98• This version was released in 1998. Although

there are a lot of new capabilities the basic structure of this operating system is almost same with Windows 95.

• Windows NT • Windows NT stands for the statements

Windows New Technology. It is the most advanced operating system of Microsoft. It can support a lot of facilities presented by UNIX systems although NIS and NFS like supports and also networking power and reliability are less than UNIX.

• Windows 2000 • This has been developed instead of the

newest version of Windows NT.

UNIXUniplexed Information and Computing System

• Unix is generally a non-real-time operating

system. It is popular because it is available for many different hardware platforms. It is very well documented so one can learn a lot of points about it from the operating system itself. There are so many source code available for it. It is also popular because it is widely used at universities and institutions for scientific research.

• Linux • We are going to give more and detailed

information about this operating system later in the third chapter.

• Some of the important features:

• Multiple user

• Multithreading

• Multitasking

• It is Virus free