Introduction to Computer Science PDF

Chapter 3 Computer hardware and software components The Computer ‫ﻣﺤﻤﺪ ﻋﺒﺪﺍﻟﻠﻪ ﻣﺤﻤﺪ ﺍﺣﻤﺪ ﺍﻟﺼﻔﻄﺎﻭﻯ‬ A computer is made up of many parts HARDWARE AND SOFTWARE:...

Chapter 3 Computer hardware and software components The Computer ‫ﻣﺤﻤﺪ ﻋﺒﺪﺍﻟﻠﻪ ﻣﺤﻤﺪ ﺍﺣﻤﺪ ﺍﻟﺼﻔﻄﺎﻭﻯ‬ A computer is made up of many parts HARDWARE AND SOFTWARE: 3.1 Hardware: Computer hardware is the collection of physical elements that constitutes a computer system. Computer hardware refers to the physical parts or components of a computer such as the monitor, mouse, keyboard, computer data storage, hard drive disk (HDD), system unit (graphic cards, sound cards, memory, motherboard and chips), etc. all of which are physical objects that can be touched. 3.1.1 Input/Output (I/O) devices – These allow you to send information to the computer or get information from the computer. Input Devices Input device is any peripheral (piece of computer 2024/2025 hardware equipment to provide 2024/2025 data and 2024/2025 control signals to an information processing system such as a computer or other information appliance. Input device Translate data from form that humans understand to one that the computer can work with. Most common are keyboard and mouse  Example of Input Devices:- 1. Keyboard 2. Mouse (pointing device) 3. Microphone 4. Touch screen 5. Scanner 6. Webcam 7. Touchpads 8. MIDI keyboard 9. Electronic Whiteboard 10.Graphics Tablets 11.Cameras 12.Pen Input 13.Video Capture Hardware 14.Microphone 15.Trackballs ‫ﻣﺤﻤﺪ ﻋﺒﺪﺍﻟﻠﻪ ﻣﺤﻤﺪ ﺍﺣﻤﺪ ﺍﻟﺼﻔﻄﺎﻭﻯ‬ 16.Barcode reader 17.Digital camera 18.Joystick 19.Gamepad Note: The most common use keyboard is the QWERTY keyboard. Generally standard Keyboard has 104 keys. Output devices An output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as a computer) which converts the electronically generated information into human- readable form. 2024/2025 2024/2025 2024/2025 Example on Output Devices: 1. Monitor 2. LCD Projection Panels 3. Printers (all types) 4. Computer Output Microfilm (COM) 5. Plotters 6. Speaker(s) 7. Projector Note Basic types of monitors are a. Cathode Ray Tube (CRT). b. Liquid Crystal Displays (LCD). c. light-emitting diode (LED). Printer types: 1- Laser Printer. 2- Ink Jet Printer. 3- Dot Matrix Printer  3.1.2 Central Processing Unit – CPU or Processor for short. The brain of a computer. Approximately 1.5 in X 1.5 in. Does all the computation/work for the computer. Central Processing Unit (CPU) A CPU is brain of a computer. It is responsible for all functions and processes. Regarding computing power, the CPU is the most important element of a computer system. ‫ﻣﺤﻤﺪ ﻋﺒﺪﺍﻟﻠﻪ ﻣﺤﻤﺪ ﺍﺣﻤﺪ ﺍﻟﺼﻔﻄﺎﻭﻯ‬ The CPU is comprised of three main parts: Arithmetic Logic Unit (ALU): Executes all arithmetic and logical operations. Arithmetic calculations like as addition, subtraction, multiplication and division. Logical operation like compare numbers, letters, or special characters Control Unit (CU): controls and co-ordinates computer components. 1. Read the code for the next instruction to be executed. 2. Increment the program counter so it points to the next instruction. 3. Read whatever data the instruction requires from cells in memory. 4. Provide the necessary data to an ALU or register. 5. If the instruction requires an ALU or specialized hardware to complete, instruct the hardware to perform the requested operation. 2024/2025 Registers: Stores the data that is 2024/2025 to be executed next, "very fast storage 2024/2025area". 3.1.3 Memory – Although memory is technically any form of electronic storage, it is used most often to identify fast, temporary forms of storage. Accessing the hard drive for information takes time. When the information is kept in memory, the CPU can access it much more quickly. ‫ﻣﺤﻤﺪ ﻋﺒﺪﺍﻟﻠﻪ ﻣﺤﻤﺪ ﺍﺣﻤﺪ ﺍﻟﺼﻔﻄﺎﻭﻯ‬ Random Access Memory – RAM. Where information is stored temporarily when a program is run. Information is automatically pulled into memory, we cannot control 2024/2025 this. RAM is cleared automatically2024/2025 when the computer is shutdown or rebooted. RAM 2024/2025 is volatile (non-permanent). Read Only Memory – ROM. More permanent than RAM. Data stored in these chips is nonvolatile -- it is not lost when power is removed. Data stored in these chips is either unchangeable or requires a special operation to change. The BIOS is stored in the CMOS, read- only memory.  Hard Drive – Where you store information permanently most frequently. This is also nonvolatile. ‫ﻣﺤﻤﺪ ﻋﺒﺪﺍﻟﻠﻪ ﻣﺤﻤﺪ ﺍﺣﻤﺪ ﺍﻟﺼﻔﻄﺎﻭﻯ‬ Optical Disk – an optical disc drive (ODD) is a disk drive that uses laser light as part of the process of reading or writing data to or from optical discs. Some drives can only read from discs, but recent drives are commonly both readers and recorders, also called burners or writers. Compact discs, DVDs, and Blu-ray discs are common types of optical media which can be read and recorded by such drives. Optical drive is the generic name; drives are usually described as "CD" "DVD", or "Bluray", followed by "drive", "writer", etc. There are three main types of optical media: CD, DVD, and Blu- ray disc. CDs can store up to 700 megabytes (MB) of data and DVDs can store up to 8.4 GB of data. Blu-ray discs, which are the newest type of optical media, can store up to 2024/2025 50 GB of data. This storage capacity is a clear advantage over the floppy 2024/2025 disk storage 2024/2025 media (a magnetic media), which only has a capacity of 1.44 MB. Flash Disk – a storage module made of flash memory chips. A Flash disks have no mechanical platters or access arms, but the term "disk" is used because the data are accessed as if they were on a hard drive. The disk storage structure is emulated. ‫ﻣﺤﻤﺪ ﻋﺒﺪﺍﻟﻠﻪ ﻣﺤﻤﺪ ﺍﺣﻤﺪ ﺍﻟﺼﻔﻄﺎﻭﻯ‬ 3.1.4 Motherboard – A circuit board that allows the CPU to interact with other parts of the computer 3.1.5 Ports – Means of connecting peripheral devices to your computer. Serial Port – Often used to connect a older mice, older external modems, older digital cameras, etc to the computer. The serial port has been replaced by USB in most cases. 9-pin connector. Small and short, often gray in color. Transmits data at 19 Kb/s. 2024/2025 2024/2025 2024/2025 Monitor Ports – Used to connect a monitor to the computer. PCs usually use a VGA (Video Graphics Array) analog connector (also known as a D-Sub connector) that has 15 pins in three rows. Typically blue in color. Because a VGA (analog) connector does not support the use of digital monitors, the Digital Video Interface (DVI) standard was developed.  LCD monitors work in a digital mode and support the DVI format. At one time, a digital signal offered better image quality compared to analog technology. However, analog signal processing technology has improved over the years and the difference in quality is now minimal. Parallel Port – Most often used to connect a printer to the computer. 25-pin connector. Long and skinny, often pink in color. Transmits data at 50-100 Kb/s. ‫ﻣﺤﻤﺪ ﻋﺒﺪﺍﻟﻠﻪ ﻣﺤﻤﺪ ﺍﺣﻤﺪ ﺍﻟﺼﻔﻄﺎﻭﻯ‬ USB Port – Universal Serial Bus. Now used to connect almost all peripheral devices to the computer. USB 1.1 transmits data at 1.5 Mb/s at low speed, 12 Mb/s at full speed. USB 2.0 transmits data at 480 Mb/s. 2024/2025 2024/2025 2024/2025 Firewire/ IEEE 1394 Port – Often found on Apple Computers. Often used with digital camcorders. Firewire transmits data at 400 Mb/s. Firewire 1394B (the new firewire) transmits data at 3.2 Gb/s. PS/2 Port - sometimes called a mouse port, was developed by IBM. It is used to connect a computer mouse or keyboard. Most computers come with two PS/2 ports.  Ethernet Port – This port is used for networking and fast internet connections. Data moves through them at speeds of either 10 megabits or 100 megabits or 1 gigabit (1,000 megabits) depending on what speed the network card in the computer supports. Little monitor lights on these devices flicker when in use. ‫ﻣﺤﻤﺪ ﻋﺒﺪﺍﻟﻠﻪ ﻣﺤﻤﺪ ﺍﺣﻤﺪ ﺍﻟﺼﻔﻄﺎﻭﻯ‬ 3.1.6 Power Supply – Gives your computer power by converting alternating current (AC) supplied by the wall connection to direct current (DC). 3.1.7 Expansion Cards – Used to add/improve 2024/2025 functionality to the computer. 2024/2025 2024/2025 Sound Card – Used to input and output sound under program control. Sound cards provide better sound quality than the built in sound control provided with most computers. Graphics Card – Used to convert the logical representation of an image to a signal that can be used as input for a monitor.  Network Card – Used to provide a computer connection over a network. Transmit data at 10/100/1000 Mb/s. ‫ﻣﺤﻤﺪ ﻋﺒﺪﺍﻟﻠﻪ ﻣﺤﻤﺪ ﺍﺣﻤﺪ ﺍﻟﺼﻔﻄﺎﻭﻯ‬ 3.1.8 CD ROM – A device used to read CD-ROMs. If capable of writing to the CD-ROM, then they are usually referred to as a ‘burner’ or CD-RW. 3.1.9 DVD ROM – A device that is used to read DVDs/CDs. If capable of writing to the DVD, then it is often referred to as a DVD-burner 2024/2025 or a DVD-RW. 2024/2025 2024/2025 3.1.10 Floppy Drive – A device that is used to read/write to floppy diskettes. 3.1.11 Fan – Keeps your computer cool. If the inside of your computer becomes too hot, then the computer can overheat and damage parts.  3.1.12 Heatsink – Used to disperse the heat that is produced inside the computer by the CPU and other parts by increasing surface area. 3.1.13 The little parts – Capacitors – store energy, Resistors – allows a current through, Transistors – a valve which allows currents to be turned on or off. ‫ﻣﺤﻤﺪ ﻋﺒﺪﺍﻟﻠﻪ ﻣﺤﻤﺪ ﺍﺣﻤﺪ ﺍﻟﺼﻔﻄﺎﻭﻯ‬ 3.1.14 Case –(Tower if standing upright.) What your motherboard, CPU, etc is contained in. 2024/2025 2024/2025 2024/2025 The three main components of a computer: 1. CPU – Central Processing Unit, coordinates all actions that occur in the system, executes program instructions. 2. Memory – Used to store information. 3. I/O Devices – input/output devices, which allow you to obtain or display data. 3.2 Software Software is a generic term for organized collections of computer data and instructions, often broken into two major categories: system software that provides the basic non- task-specific functions of the computer, and application software which is used by users to accomplish specific tasks. Software Types A. System software is responsible for controlling, integrating, and managing the individual hardware components of a computer system so that other software and the users of the system see it as a functional unit without having to be concerned with the low-level details such as transferring data from memory to disk, or rendering text onto a display.  Generally, system software consists of an operating system and some fundamental utilities such as disk formatters, file managers, display managers, text editors, user authentication (login) and management tools, and networking and device control software. B. Application software is used to accomplish specific tasks other than just running the computer system. Application software may consist of a single program, such as an image viewer; a small collection of programs (often called a software package) that work closely together to accomplish a task, such as a spreadsheet or text processing system; a larger ‫ﻣﺤﻤﺪ ﻋﺒﺪﺍﻟﻠﻪ ﻣﺤﻤﺪ ﺍﺣﻤﺪ ﺍﻟﺼﻔﻄﺎﻭﻯ‬ collection (often called a software suite) of related but independent programs and packages that have a common user interface or shared data format, such as Microsoft Office, which consists of closely integrated word processor, spreadsheet, database, etc.; or a software system, such as a database management system, which is a collection of fundamental programs that may provide some service to a variety of other independent applications. Comparison Application Software and System Software System Software Application Software Computer software, or just software is a general term primarily used for digitally Application software, also known as an 2024/2025 stored data such as computer programs 2024/2025 2024/2025 application or an "app", is computer and other kinds of information read and software designed to help the user to written by perform specific tasks. computers. App comes under computer software though it has a wide scope now. Example: 1) Microsoft Windows 1) Opera (Web Browser) 2) Linux 2) Microsoft Word (Word Processing) 3) Unix 3) Microsoft Excel (Spreadsheet software) 4) Mac OSX 4) MySQL (Database Software) 5) DOS 5) Microsoft PowerPoint (Presentation Software) 6) Adobe Photoshop (Graphics Software) Interaction: Generally, users do not interact with Users always interact with application system software as it works in the software while doing different activities. background. Dependency: System software can run independently of Application software cannot run without the the presence of the system software. application software.  Unit of Measurements Storage measurements: The basic unit used in computer data storage is called a bit (binary digit). Computers use these little bits, which are composed of ones and zeros, to do things and talk to other computers. All your files, for instance, are kept in the computer as binary files and translated into words and pictures by the software (which is also ones and zeros). This two number system, is called a “binary number system” since it has only two numbers in it. The decimal number system in contrast has ten unique digits, zero through ‫ﻣﺤﻤﺪ ﻋﺒﺪﺍﻟﻠﻪ ﻣﺤﻤﺪ ﺍﺣﻤﺪ ﺍﻟﺼﻔﻄﺎﻭﻯ‬ nine. Computer Storage units Bit BIT 0 or 1 Kilobyte KB 1024 bytes Megabyte MB 1024 kilobytes Gigabyte GB 1024 megabytes Terabyte TB 1024 gigabytes Size example 1 bit - answer to an yes/no question 1 byte - a number from 0 to 255. 2024/2025 2024/2025 2024/2025 90 bytes: enough to store a typical line of text from a book. 4 KB: about one page of text. 120 KB: the text of a typical pocket book. 3 MB - a three minute song (128k bitrate) 650-900 MB - an CD-ROM 1 GB -114 minutes of uncompressed CD-quality audio at 1.4 Mbit/s 8-16 GB - size of a normal flash drive Speed measurement: The speed of Central Processing Unit (CPU) is measured by Hertz (Hz), which represent a CPU cycle. The speed of CPU is known as Computer Speed. CPU SPEED MEASURES 1 hertz or Hz 1 cycle per second 1 MHz 1 million cycles per second or 1000 Hz 1 GHz 1 billion cycles per second or 1000 MHz  Chapter 4 Data Representation and Number systems ‫ﻣﺤﻤﺪ ﻋﺒﺪﺍﻟﻠﻪ ﻣﺤﻤﺪ ﺍﺣﻤﺪ ﺍﻟﺼﻔﻄﺎﻭﻯ‬ 4.1 Number systems are the technique to represent numbers in the computersystem architecture, every value that you are saving or getting into/from computer memory has a defined number system. Computer architecture supports following number systems. Binary number system Octal number system Decimal number system Hexadecimal (hex) number system 2024/2025 2024/2025 2024/2025 1) Binary Number System A Binary number system has only two digits that are 0 and 1. Every number(value) represents with 0 and 1 in this number system. The base of binary number system is 2, because it has only two digits. 2) Octal number system Octal number system has only eight (8) digits from 0 to 7. Every number (value) represents with 0,1,2,3,4,5,6 and 7 in this number system. The base ofoctal number system is 8, because it has only 8 digits.