KESHI_2024_052931.docx

LECTURE NOTE INFORMATION AND COMMUNICATION TECHNOLOGY PREPARED BY MURTALA M. CHAFE INTRODUCTION In the past Computer Technology and Communication Technology developed independently, like rails in a rail road track that never Marge. However, it is an umbrella that supports the creating, processi...

LECTURE NOTE INFORMATION AND COMMUNICATION TECHNOLOGY PREPARED BY MURTALA M. CHAFE INTRODUCTION In the past Computer Technology and Communication Technology developed independently, like rails in a rail road track that never Marge. However, it is an umbrella that supports the creating, processing (manipulating), communication and distribution of information together with the related technology in order to achieve a new environment. DIFINATION OF A COMPUTER A computer can be define as an electronic device which under the control of stored programs accept data as an input and process it into a useful and meaningful information as an output for decision making. And this information can be display as a soft copy via visual display unit (VDU) or print it as a hard copy via printer or store it in the computer memory for future use in order to speed up problem solving and increase productivity. BASIC COMPONENTS OF A COMPUTER SYSTEM A computer system consist of two (2) main components, namely 1. Hardware 2. Software 1. HARDWARE: Is the general term used to describe all the physical parts of the computer which we see and operate on. The hardware includes among other devices, Keyboard, Monitor, Mouse Central Processing Device (CPU) etc. The hardware is categorized into two (2) parts namely \(i) The Central Processing Unit (ii) The peripherals. THE CENTRAL PROCESSING UNIT (CPU) DIAGRAM -- -- -- -- THE CENTRAL PROCESSING UNIT (CPU): The CPU otherwise called PROCESSOR is made of the following: a\. The Control Unit (CU) b\. The Arithmetic and Logic Unit (ALU) c\. The Main Memory A. THE CONTROL UNIT (CU): B. THE ARITHMETIC AND LOGIC UNIT (ALU): C. THE MAIN MEMORY: The Main Memory is divided into: i. ROM (Read Only Memory) \(ii) RAM (Random Access Memory) ROM (Read Only Memory): Features of ROM (Read Only Memory): a\. It is non-volatile i.e. the content is retained even after failure b\. It is read only c\. It occupies a very small space of the main memory d\. The memory is permanent RAM (Random Access Memory): Features of RAM (Random Access Memory): a\. It is volatile i.e. the content is erased at any time power failure. b\. It can be erased at random i.e. Reading and Writing takes place in. c\. It occupies a large portion of the memory. d\. It is a temporary storage. \(II) THE PERIPHERALS. COMPUTER SOFTWARE *Categories of software* ### ### ### ### System Software Broadly speaking, systems software consists of three elements: 1. Those programs concerned with the internal control and co-ordination of all aspects of the computer system, namely the *operating system;* 2. A number of other programs providing various services to users. These services include *translators* for any languages supported by the system and *utility programs* such as programs editors and other aids to programming; 3. *Graphical user interfaces* (GUls) providing intuitive, easily learned methods for using microcomputer systems. **Operating systems** ===================== The main functions of operating systems ======================================= 1. interpretation of the command language by which operators can communicate with the operating system; 2. error handling. For example, detecting and reporting inoperative or malfunctioning peripherals; 3. protection of data files and programs from corruption by other users; 4. Security: protection of data files and programs from unauthorized use; 5. Accounting: accounting and logging of the use of the computer resources. 6. Program Loading to the main memory for processing 7. Multiprogramming 8. Interrupt handling 9. Job Sequencing 10. File Management 11. Job Scheduling 12. Peripheral Control 13. Recovery from System Failure Types of Operating System i. *Single Program OS:* allow one user's program at a time ii. *Simple Batch Systems:* Provides multiprogramming of batch programs but have few facilities for multi-access iii. *Multi-access and Time-sharing:* Allows multiple access to system resources and therefore share processors time to cope with numerous users iv. *Real-time system:* Used in any real time data processing technique **System Services** =================== **Language Translators (Processors)** ===================================== **Utility Programs** ***1. Editors:*** These permit the creation and modification of source programs and data files. =============================================================================================== ***3. File managers:*** These simplify and facilitate a number of operations connected with program development and maintenance such as keeping backup copies of important files; deleting, creating, merging, sorting files etc. ================================================================================================================================================================================================================================= **Graphical User Interfaces (GUls)** **USER APPLICATIONS SOFTWARE** ============================== **COMMERCIAL PACKAGES:** ======================== I. Airline Seat Reservation, II. Theatre Seat Reservation III. Hotel Room Reservation. IV. Point of Sales Software V. A Payroll Program **GUIDELINE FOR ACQUISITION OF APPLICATION SOFTWARE** 2\. It must be of high performance 3\. The software to be acquired must be one with enough ease in learning. 4\. The software to be acquired must be available when needed 5\. If a software package is complex then training is required **CHARACTERISTICS OF COMPUTERS** 1. **Electronic in nature:** The basic components of computer are electronics, such as integrated circuits, data input into the computer are represented in form of electronic pluses, operations performs by computer are electronic. 2. **High Speed:** The computers have the ability to execute or carry out instructions at very great speed. 3. **Accuracy:** 4. **Storage:** 5. **Consistency:** Computers have the ability to consistently follow instructions without getting tired. 6. **Repetitiveness:** Computers have the ability to continue processing over an extended period. 7. **Complexity:** **8. Volume:** Computers are very suitable for handling large amount of data. **9. Automatic:** 10\. Versatility: THE CONCEPT OF DATA AND INFORMATION DATA: INFORMATION Name: Nura Reg no.: 2023/2024 Level: 300 Age: 25 G.P.: 3.5 The meaning of which is now clear. TYPES OF DATA Data about any business may be categorized as follows 1\. External/Environment Data: This includes matters relating to social, political and economic factors 2\. Competitive Data: This type of data embraces details with regard to the past performance of main competitors, their present activities and future plans 3\. Qualitative and Quantitative Data: This type of data relates to quality control, levels of performance, costs, overheads profits and losses, financial strengths and weaknesses relating to cash flows and lines of credits. 4\. Organizational/Internal Data: This type of data relate to manpower levels, structure of the department, duties of personnel etc. DATA PROCESSING METHODS 1\. Manual method 2\. Mechanical method 3\. Electronic method 1\. MANUAL METHOD: 2\. MECHANICAL METHOD: 3\. ELECTRONIC METHOD: DATA PROCESSING OPERATIONS 1. *Data capturing:* This is the collection of data at the source point. It is the process of gathering raw data or recording raw data from event. 2. *Verification:* This involve checking of captured data to be sure that the source is genuine and that the data is recorded correctly. 3. *Arranging:* This involves placing of data in a logical sequence or order. It can either be in ascending or descending order. 4. *Grouping:* This is the classification of data elements in certain category such as unit, type. Size. Etc 5. *Calculation:* This involve s all the mathematical and logical manipulations performed on data. It may be summing up of sales to get total or any form of decision making based on data element. 6. *Storage/retrieval:* Storage is the process of keeping data onto a storage media for future use while retrieval is the recovery of specific data from a stored medium. 7. *Reproducing:* This is the replication of data on more than one storage area e.g copying a processed data in a diskette while the master copy remains in the Hard disk. 8. *Communication:* This involves transfer of processed data to the end-user. It can be a more output displayed on the screen or in a form of report printed for the user or to be distributed for external users of such information. DATA PROCESSING TECHNIQUE *3. Distributed processing*: 4\. Centralized system USERS OF AN ORGANIZATIONAL INFORMATION 1 Internal Source. 2. External Source. INTERNAL USERS OF ORGANIZATIONAL INFORMATION a\) The board of the company or Public sector equivalent b\) Directors with functional responsibilities c.) Divisional general managers, reporting to these directors. d.) Division Heads e\) Department Heads f\) Section Heads. EXTERNAL USERS OF ORGANISATIONAL INFORMATION CATEGORIES OF INFORMATION \(1) Strategic (2) Tactical (3) Operational PROPERTIES OF *STRATEGIC INFORMATION (HIGHER):* i\) Derived from both internal and external sources ii\) Summarized. iii\) Relevant to the long term, iv\) Deals with the whole organization PROPERTIES OF *TACTICAL INFORMATION (MIDDLE):* i\) It is relevant to short and medium term. ii\) It is prepared regularly iii\) It Describes or Analyses activities of departments iv\) It is based on quantitative measures (cash flow forecasts, budgetary control or variance analysis reports and short--term purchasing requirement) *PROPERTIES OPERATIONAL INFORMATION (LOWER):* I\) Derived almost entirely from internal sources ii\) Is highly detailed iii\) Relates to the immediate term iv\) Is task specific v\) Is prepared constantly or very frequently vi\) Is largely quantitative. CLASSIFICATION OF INFORMATION: Organizational information can be classify into three parts: \(1) Present information (2) past information (3) future information QUANTITATIVE AND QUALITATIVE INFORMATION: A piece of organizational information may be quantitative or qualitative i. Quantitative-information: This type of information is measured in numerical terms, such as money or physical quantities e.g. Labour-hours, weight of material. ii. Qualitative information: This type of information is difficult to measure in quantitative terms. Examples of qualitative information can be employee moral, motivation, customer patronage, and attitude of general public. CHARACTERISTICS OF INFORMATION 1. *Accessibility:* The access time must be very minimal. That it must be already available for consumption or use, 2. *Comprehensiveness:* A good information must be complete 3. *Accuracy:* A good information must be devoid of any error. 4. *Appropriateness:* This deals with how well information relates to user's request. 5. *Timeliness:* the processing time of any good information must be very short 6. *Flexibility:* It must be able to serve more than one user. 7. *Cost-effectiveness:* The benefit of such information should be higher than it cost of acquisition. COST OF INFORMATION a. Cost of equipment \(b) Cost of stationeries \(c) Cost of consumable materials \(d) Cost of training \(e) Cost of accommodation \(f) Cost of maintenance \(g) Cost of staff \(h) Cost of security REASONS FOR THE USE OF INFORMATION Some of the reasons for the use of information are as follows: 2\. To satisfy legal documents 3\. To standardize data collection procedures Communication Media: Data Transmission and Communication Device *Computers* produce the digital data where as *telephone* produces analog data. Data transmission may be either *asynchronous* or *synchronous.* ON-LINE DATA TRANSMISSION OFF-LINE DATA COMMUNICATION ELEMENTS OF DATA COMMUNICATION a. Information source b. Message c. Transmitter d. Signal e. Receiver f. Information destination *(f) Destination:* Receipt of message by addressee. \(a) MODEM (b) front-End-Processor (c) Multiplexor TYPES OF TRANSMISSION NETWORKS Basic advantages of using Networks There are many possible advantages in using networks. The basic ones are: a. The sharing of resources (e.g computers and staff) and information. b. The provision of local facilities without the loss of central control c. The even distribution of work d. Improved communication facilities CATEGORIES OF NETWORKS COMPONENTS OF NETWORK There are three basic hardware components for a data communication network; NETWORK TOPOLOGIES INTERNET It is an international network of networks of computers linking different types of users: academic, Industries, Government, Health Institutions, military, individuals, etc for the purpose of sharing information. As a communication network among computer, the internet allows you to locate and retrieve information on other computers linked to the internet as well as send message electrically to and from another people elsewhere on the internet. Whenever internet software application is used , the client software will either be on your personal computer , the computer you log onto for access to the internet (your host), or yet another computer to which you connect in other to use client software you may not have on your computer. As you navigate through the internet, you will find yourself logged onto different host computers, sometimes gaining access to different client programs and also accessing different services; it can be complicated. Fortunately, the purpose of advanced internet software is to hide these complexities from users so as to achieve success. The internet has six application protocols; 1\. Electronic mail (E-mail) 2\. World wide web 3\. Hypertext transfer Protocol or (HTTP) 4\. Gopher 5\. Telnet 6\. File Transfer protocol (FTP) USES OF THE INTERNETS The various uses of the internet are: *1. Electronic mail (E-mail):* E-mail is a method of sending messages back and forth among people with internet addresses as well as on other network with mail addresses or connections to the internet. The main common feature are that the massage are converted to electrical signals for the purpose of transmission. It is primarily an alternative to the conventional postal service. Electronic mail is one of the most useful features of the internet and it is often the application with which people begin. As a means of sending messages back and forth among people with internet address as well as people on other network with mail connections to the internet, the E-mail support both person to person communications (that is delivered to the electronic address of the intended recipient ) and one to many transmission in which information automatically sent to a list of people. 2\. World wide web (WWW): world wide Web is the most, exciting new tool for the Internet. It is based on the technology called hypermedia. With hypermedia information in one document can be linked to another related information can consist of not only text but graphics, audio and video information as well. WWW. Is an ambitious, exciting and powerful attempt to link connected information wherever it may be located on the internet, allowing the user to easily access and retriever related files 3\. Telnet: telnet allows you to log on to another computer on the net. The computer onto which you are logging is known as remote computer. Once you are logged onto a remote computer, it becomes as if your keyboard was attached to that computer, which then serve as your host. You can do whatever the people are regularly attached to the computer can do. It is also possible that the computer you currently using to access the internet that does not have the client software with which you want to work you can use Telnet to log onto another computer on the internet that does not have the right tools. *4. FILE TRANSFER PROTOCOL (FTP):* File transfer protocol has the facilities that can be used for moving files from one computer to another. It is the common language for sharing data. Unlike Talent in which you must often know a specific password to successful log onto the remote computer anonymous FTP has become a common place. With anonymous FTP, anyone on the internet may transfer files from and sometimes to a remote system using the word anonymous as the user identification. 5\. USENET: Usenet is a network of several thousand online bulletin organized in to topic-oriented "new group". Within these news groups, people read and posted related massages. These are already more than 10,000 news groups with participant ranging from computer enthusiasts to music composers. Usenet is one of the many networks connect to and accessible through the internet. 1. *GOPHER* Gopher was the first program to investigate the information search and retrieval process on the internet. Like other internet applications, Gopher consist of servers and client software. More than 2.000 gopher servers have been linked. When you find something that you want, the client software retrieves it for you through menu-based commands. With Gopher, it does not matter where exactly the information you want is located. It does not matter, what kind of information you want to retrieve. Not does it matter what tool you need to use to retrieve that information. You use tool from the menu to perform each operation. BENEFITS OF INTERNET APPLICATION a. Downloading of information b. Advertisement c. Accessing newspapers, magazines and academic journals d. On-line banking e. Accessing international media (CNN, BBC, VOA) Comparison between E-mail and postal mail E-MAIL POSTAL MAIL a. Faster slow b. Efficient Inefficient c. Uses telephone line message travels through air or sea d. Medium of message is electronic medium of message is paper