Introduction to Computing Lecture 1 PDF

Chapter 1 1 2 3 1. Speed 2. Accuracy 3. Diligence 4. Storage Capability 5. Versatility 4 Speed: The computer can process data very fast, at the rate of millions of instructions per second Accuracy: The computer provides a high degree of accuracy. For e...

Chapter 1 1 2 3 1. Speed 2. Accuracy 3. Diligence 4. Storage Capability 5. Versatility 4 Speed: The computer can process data very fast, at the rate of millions of instructions per second Accuracy: The computer provides a high degree of accuracy. For example, the computer can accurately give the result of a division of any two numbers up to 10 decimal places. Diligence: When used for a longer period of time, the computer does not get tired or fatigued. It can perform long and complex calculations with the same speed and accuracy from the start till the end. 5 Storage Capability: Large volumes of data and information can be stored in the computer and retrieved whenever required. A limited amount of data can be stored, temporarily, in the primary memory. Secondary storage devices like floppy disks and compact disks can store a large amount of data permanently. Versatility: The computer is versatile in nature. It can perform different types of tasks with the same ease. At one moment you can use the computer to prepare a letter document and in the next moment, you may play music or print a document. 6 7 8 9 10 11 12 13 14 Computers can perform four general operations, which comprise the information processing cycle. Ø Input Ø Process Ø Output Ø Storage 15 16 17 18 19 20 21 22 Ø It must be given a detailed list of instructions, called a compute program or software, that tells it exactly what to do. Ø Before processing a specific job, the computer program corresponding to that job must be stored in memory. Ø Once the program is stored in memory the computer can start the operation by executing the program instructions one after the other. 23 Computer Components 24 q Hardware q Software 25 Ø Computer hardware is the collection of physical elements” Tangible objects” that constitute a computer system. Ø The actual machinery, wires, transistors, and circuits … etc. 26 27 Computer Programs , instructions, and data 28 Hardware 29 1. Input Unit 2. Central Processing Unit 3. Primary Memory Unit 4. Secondary storage Units 5. Output Unit 30 31 Input Devices 32  Input device is any peripheral (a piece of computer hardware equipment to provide data and control signals to an information processing system such as a computer or other information appliance. Input devices translate data from a form that humans understand to one that the computer can work with. Most common are keyboard and mouse. 33 34  Keyboard Mouse (pointing device) Microphone Touch screen Scanner Webcam Touchpads MIDI keyboard Graphics Tablets Cameras Pen Input Video Capture Hardware Microphone Trackballs Barcode reader Digital camera Joystick Gamepad Electronic Whiteboard Note: The most common use keyboard is the QWERTY keyboard. Generally standard Keyboard has 104 keys 35 Central Processing Unit (CPU) 36 37 The CPU is comprised of three main parts 1. Arithmetic Logic Unit (ALU ) 2. Control Unit (CU) 3. Registers: Stores the data that is to be executed next. 38 Arithmetic Logic Unit ( § Executes all arithmetic and logical operations. § Arithmetic calculations like addition, subtraction, multiplication, and division. § Logical operations like comparing numbers, letters, or special characters 39 Control Unit (CU): controls and coordinates computer components. § Read the code for the next instruction to be executed. § Increment the program counter so it points to the next instruction. § Read whatever data the instruction requires from cells in memory. § Provide the necessary data to an ALU or register. § If the instruction requires an ALU or specialized hardware to complete, instruct the hardware to perform the requested operation. 40 Registers Stores the data that is to be executed next, "very fast storage area". 41 Memory 42 43 1. RAM 2. ROM 44 Random Access Memory )RAM(: is a memory scheme within the computer system responsible for storing data on a temporary basis, so that it can be promptly accessed by the processor as and when needed. It is volatile in nature, which means that data will be erased once the supply to the storage device is turned off. RAM stores data randomly and the processor accesses these data randomly from the RAM storage. RAM is considered "random access" because you can access any memory cell directly if you know the row and column that intersect at that cell. 45 Read Only Memory (ROM): ROM is a permanent form of storage. q ROM stays active regardless of whether the power supply to it is turned on or off. q ROM devices do not allow data stored on them to be modified. 46 § Stores data and programs permanently § It’s retained after the power is turned off Main Examples 1. Hard Disk 2. Optical Disk 3. Flash memory 47  Called Disk drive or HDD Stores and provides relatively quick access to large amounts of data. Stores data on an electromagnetically charged surface or set of surfaces. 48 An optical disc drive (ODD) is a disk drive that uses laser light to store data. There are three main types of optical media: CD, DVD, and Blu-ray disc Ø CD “Compact Disk” can store up to 700MB Ø DVD “ Digital Video Disk “ can store up to 8.4 GB Ø Blu-ray disc. can store up to 50 GB 49 § A storage module made of flash memory chips. § 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. 50 What are the differences between RAM as a main memory and HDD as a Secondary Memory? 51 52 Output Unit 53 Ø 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) Ø Converts the electronically generated information into human-readable form. 54  Monitor LCD Projection Panels Printers (all types) Computer Output Microfilm (COM) Plotters Speaker(s) Projector 55 1. A monitor CRT: Cathode Ray Tube LCD: Liquid crystal display most familiar these days 56 2. Printer: Transfers data from a computer onto paper Printer types: 1- Laser Printer. 2- Ink Jet Printer. 3- Dot Matrix Printer 57 Software 58 Software is a generic term for organized collections of computer data and instructions, often broken into two major categories: 1. system software 2. application software 59  System software Ø Known as Operating System Ø It is responsible for controlling, integrating, and managing the individual hardware components of a computer system Ø Windows is an example of an OS. Examples of System Software: 1) Microsoft Windows 2) Linux 3) Unix 4) Mac OSX 5) DOS 60 It is used to accomplish specific tasks other than just running the computer system. It may consist of: ◦ A single program, such as an image viewer; ◦ A collection of programs (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. 61 It is used to accomplish specific tasks other than just running the computer system. It 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 collection of programs (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. 62 Unit of Measurements 63  Storage Units Bit BIT 0 or 1 Byte B 8 bits Kilobyte KB 1024 bytes Megabyte MB 1024 kilobytes Gigabyte GB 1024 megabytes Terabyte TB 1024 gigabytes 64  1 bit - answer to a yes/no question 1 byte - a number from 0 to 255. 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 pocketbook 3 MB - a three-minute song (128k bitrate) 650-900 MB – a CD-ROM 1 GB -114 minutes of uncompressed CD-quality audio at 1.4 Mbit/s 8 -16 GB – the size of a normal flash drive 65 A. 10 B is equivalent to 10 * 8 = 80 bits B. 3MB is equivalent to how many Bits? Answer: 3 *1024 = 3072 KB 3072*1024 = 3145728 B 3145728 * 8 = 25165824 bits 66 Ø The speed of the CPU is measured by a unit called Hertz (Hz). Ø 1 Hz represents 1 cycle per second. Ø The speed of the CPU is known as Computer Speed. 67  CPU SPEED MEASURES 1 hertz or Hz 1 cycle per second 1 MHz 1 million cycles per second or 1000000 Hz 1 GHz 1 billion cycles per second or 1000000 MHz 68 Computer Classification 69 Computers can be classified by size and power to: 1. Personal computer )PCs( 2. Minicomputer 3. Mainframe: 4. SuperComputer 70 71 Personal computer (PCs): a small, single-user computer based on a microprocessor. In addition to the microprocessor, a personal computer has a keyboard for entering data, a monitor for displaying information, and a storage device for saving data. 72 Minicomputer: a multi-user computer capable of supporting from 10 to hundreds of users simultaneously. Mainframe: a powerful multi-user computer capable of supporting many hundreds or thousands of users simultaneously. Supercomputer: an extremely fast computer that can perform hundreds of millions of instructions per second. 73 Compare between the previous type of computers based on ◦ Price ◦ Processing Speed ◦ Storage Capacity ◦ Powerful ◦ Single-user or Multi-user ◦ Computer Size ◦ Companies size 74 Laptop and Smartphone Computers 75 Ø Is a portable computer. Ø personal computer that can be easily carried and used in a variety of locations. Ø run the same software and applications as in PCs 76 Netbook Computer Ø A netbook is a type of laptop that is designed to be even more portable. Ø Cheaper and less powerful than laptops or desktops. Ø They are generally less powerful than other types of computers, but they provide enough power for email and internet access, which is where the name "netbook" comes from. 77 § A mobile device is basically any handheld computer. § It is designed to be extremely portable. § Some mobile devices are more powerful Types: 1.Tablet Computers 2.Smartphones 78 § designed to be portable. § The most obvious difference is that tablet computers don't have keyboards or touchpads. Instead, the entire screen is touch-sensitive, allowing you to type on a virtual keyboard and use your finger as a mouse pointer. § Best used for tasks like web browsing, watching videos, reading e-books, and playing games. 79 § A powerful mobile phone. § Designed to run a variety of applications in addition to phone service. § Internet access is an important feature of smartphones. (3G or 4G)(Wi-Fi Service) Compare it with the tablet? smartphones are more compact, focused on communication, and highly portable, while tablets offer a larger screen for diverse tasks, including productivity and entertainment. The choice between the two often depends on individual preferences and specific use cases. 80 Data, Information, and Knowledge 81 Data: ◦ Facts and figures that relay something specific ◦ But which are not organized in any way and which provide no further information regarding patterns ◦unstructured facts and figures 82 Information: § For data to become information, it must be contextualized, categorized, calculated, and condensed. (Processing) § It is data with relevance and purpose. 83 84 Data: symbols Information: data that are processed to be useful; provides answers to "who", "what", "where", and "when" questions Knowledge: application of data and information; answers "how" questions 85 § Data: Raw numbers: 2, 4, 6, 8, 10. § Information: Organized data with context - Test scores of students (Alice, Bob, Carol, David, and Emma). Alice: 2 Bob: 4 Carol: 6 David: 8 Emma: 10 § Knowledge: Derived from information - The average test score is 6, indicating the average performance of the students. 86 Processing data produces information, and processing information produces knowledge. 87 Data Representation 88 89 90 91 The decimal value 150 can be represented as 10010110 92 93 q Suppose we limit our text to characters in the standard English alphabet. If we include lower-case letters (26), upper-case letters (26), and punctuation (space, comma, period, newline, semi-colon), we have 57 different symbols to represent. q We can assign a unique number to each symbol, and encode the corresponding number with six bits (this leaves seven values unused since six bits can distinguish 64 values). 94 For example, we could encode using the mapping shown in the following table 95 q We can also use bit sequences to represent complex data like pictures, movies, and audio recordings. q First, consider a simple black-and-white picture: Since the picture is divided into discrete squares known as pixels, we could en-pixel code this as a sequence of bits by using one bit to encode the color of each pixel 96 q This image is 16x16, so has 256 pixels in total. q We could represent the image using a sequence of 256 bits (starting from the top left corner): q for example, using 1 to represent black, and 0 to represent white. 97  Accuracy: Accuracy means that data is free from errors and reflects the true values or facts. In a medical laboratory, accurate data is crucial for patient diagnoses. Inaccurate test results could lead to incorrect medical decisions. Validity: means data is correct and fits the established rules. Think of a quiz where correct answers get a "+" and wrong answers get a "−". If a teacher mistakenly marks a correct answer as "−", the data lacks validity. 98 Reliability: refers to data consistency and stability over time and across sources. Think of a weather forecast on your phone. If it consistently provides the same weather information for your location every time you check, you're likely to trust it. In contrast, if it frequently gives different forecasts for the same day, it's unreliable, and you might not rely on it for your plans. Timeliness: refers to the data being available when needed and up to date. In a , timely data is critical. Delayed data could lead to inaccurate forecasts and impact public safety. 99 Relevance: Data captured should be relevant to the purposes for which it is to be used. often target specific customer segments so recommending products unrelated to a customer's interests would reduce the effectiveness of the campaign Completeness: indicates that the without omissions. In an academic database, student records should include all necessary information, such as names, contact details, course enrollment, and grades. Incomplete records, missing grades, or contact information gaps can hinder effective communication and academic tracking. 100 101