Showing posts with label ICT & COMPUTING. Show all posts
Showing posts with label ICT & COMPUTING. Show all posts

Friday, 13 July 2018

NETWORK CABLES AND COMPUTER CABLE


Network Cables
The main reason why we set up a network is for easy transfer of digital information from one computing device to another. We can set up a network in two forms: either wireless or wired. For wired network, we make use of some cables that are linked together by connectors to facilitate communication. Also for wireless, infrared, or radio-frequency transmitter are used to enhance communication but they are usually low speed compared to wired networks.

A cable is the medium through which information transverses from one network device to another. There are several types of cable which are commonly used with Local Area Networks (LANs).
  1. Twisted Pair: It is a type of wiring in which two conductors are twisted together for the purposes of cancelling out electromagnetic interference (EMI) form external sources. Twisted pair is the ordinary copper wire that connects home and many business computers to the telephone company. To reduce crosstalk or electromagnetic induction between pairs of wire, two insulator copper wires are twisted around each other.
  2. Coaxial Cable: It is an electrical cable with an inner conductor surrounded by a flexible, tubular insulating layer and a tubular component parts. A plastic layer provides insulation between the centre conductor and a braided metal shield. The metal shield helps to block any outside interference.
Although, coaxial cabling is difficult to install, it is highly resistance to signal interference. In addition, it can support greater cable lengths between network devices than twisted pair cable. It exists in two types: thin and thick coaxial cables.

  1. Fibre Optic: It is long, thin strands of very pure glass about the diameter of a human hair. They are arranged in bundles called optical cables and used to transmit light signals over long distances. It has the ability to transmit signals over much longer distances than coaxial and twisted pair. It also has capability to carry information at vast greater speeds. Fibre optic cables are being employed in our modern day GSM, telephone system, cable TV system or internet.
  1. Telephone Cable: telephone wires were used in those days to connect computers together on a network. The modem is usually installed with the computers to the converter (modulate) signal at a source computer to analogue signal in other to transmit it on the telephone wires. At the receiving computer end, the analogue signal is converted back (demodulate) to digital signal. Telephone wires are usually paired copper wires and are normally packed together in a thick black cable.

Connectors
A registered jack (RJ) is a standardized physical network interface-both jack construction and wiring pattern-for connecting telecommunications or data equipment to a service provided by a local exchange carrier of or long distance carrier. The standard designs for these connectors and their wiring are named as RJ-11, RJ-45 etc.
  1. RJ-45: The standard connector for unshielded twisted pair cabling is a RJ-45 connector. RJ45 connectors are most commonly seen with Ethernet cables and networks.
RJ45 connectors feature eight pins to which the wire strands of a cable interface electrically. Standard RJ-45 pinouts define the arrangement of the individual wires needed when attaching connectors to a cable.
  1. RJ11: it standard dictates a 2 wire connection, whereas RJ14 uses a 4-wire configuration, and RJ-25 uses six wires. Plugs and jacks of these type are often called modular connectors, which originally distinguished them from older telephone connectors which were very bulky or wired directed to the wall and therefore not accommodating of modular systems.
  1. T-Connectors: it is mostly used with coaxial cables such as RG-58 A/U cable mainly used with the 10Base-2 Ethernet system. It is a type of electric connector that joins a conductor to anther conductor at right angles to it. It has a T-shape.
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Computer Cables
Computer cables form the connections between computer systems and their peripheral devices.  They are physical implementations of interface standards for transmitting data between computers and peripherals such as keyboards, display devices, mass storage units, and printers.  
  1. Power cables: it is an assembly of two or more electrical conductors, usually held together with an overall sheath. The assembly is used for the transmission of electronic power. Power cables may be installed as permanent wiring within buildings, buried on the ground, run overhead or exposed.
  1. Data cables – Data cables comprises all cables needed for the input of data into the computer and the output of data from the computer system. They connect the input and output devices of a computer.

Printer cable: it refers to the cable that carries data between a computer and a printer. There are different types of cables depending on your printer e.g. parallel, firewire, USb and so on.
Universal Serial Bus (USB): You can use USB cables to connect most new devices to your computer including flash memory sticks, portable media players, internet modems and digital cameras.
Computer accessories like mice, keyboards, webcams, portable hard-drives, microphones, printers, scanners and speakers can also be connected to the computer through USB ports. Additionally, USB cables are also used for charging a variety of gadgets including mobile phones or for transferring data from one computer to another.
Monitor cable: it is used to connect the monitor (VDU) to the CPU. Attached at both end of the cable is a connector which could be either pin (male plug) of holes (female plug).
Serial cable: it is used to transfer information between two devices using serial communication. A serial communication is the process of sending data line bit at a time sequentially, over a communication channel or computer bus. Serial communication is used for all long-haul communication and most computer networks where the cost of cables and synchronization difficulties made parallel communication impractical.

Assignments
  1. Briefly explain the reason why we set up network connection.
  2. Itemize three types of network cables.
  3. Juxtapose the suitable network cable to use where there is a great tendency of interference.
  4. List the importance of using a fiber optic cable.
  5. Highlight any four data cable.
  6. Briefly explain a twisted pair cable.

Saturday, 21 April 2018

ICT AS A TRANSFORMATIONAL TOOL

MEANING OF ICT
ICT stands for information and communication technology. The plural form is information and communication technologies (ICTs). They are a diverse set of technological tools and resources used to create process, store, retrieve, communicate, and manage information. ICTs comprise a range of technology products and activities that enable the recording, storage, recording, storage, processing and retrieval, transition, and reception of information.

EXAMPLES OF ICT GADGETS
ICT gadgets include;
[1] Computers
[2] Telephone (GSM)
[3] Cellular network
[4] Satellite communications
[5] Television
[6] The Internet.

THE BENEFITS OF ICT
The benefits of ICT are numerous which include the following;
1.Timely, better and cheaper access to knowledge and information.
2.Speeds up transactions and processes.
3.Provides opportunities for human beings to interact with one another in new ways easily.
4.Makes distance to become irrelevant in business transactions and dealings.
5.ICT has brought about innovative ways of interaction.
6.It provides employment opportunities to people globally  
7.It is very useful as a medium of instruction in schools. It also makes people to acquire knowledge especially in ICT.
8.When used in governance, it leads to efficiency. This is called e-administration.
9.It is useful in medicine for medical diagnosis.

SUB-TOPIC 4: DISADVANTAGES OF ICT
Despite the benefits of ICT, it has some disadvantages some of which include the following:
1.It can lead to job loss as a result of computerization of transactions in an office.
2.Youth often abuse the internet by using it mostly for entertainment, watching pornography and using it to commit crime, notably cybercrime.
3.ICT use often leads to a breakdown in social bonds between people. 4.People prefer to send e-mails or call their loved ones on phone rather than visiting them.
5.Extensive use of ICT often leads to some health implications like eye strains, backaches, etc.
6.ICT use can lead to computer addiction, obsessive computing behavior and stress.
7.Advent of ICT has led to infringement of people’s privacy and confidentiality of information today can no longer be guaranteed.

GSM (GLOBAL SYSTEM FOR MOBILE COMMUNICATION)
The Global System for Mobile Communication(GSM;original from Group Special Mobile) is the most popular standard for mobile phones in the world. GSM service is used by over 2 billion people across more than 212 countries and territories.The ubiquity of the GSM standard makes international roaming very common between mobile phone operators, enabling subscribers to use their phones in many part of the world. GSM differs significantly from its predecessors in that it is considered a second generation (2G) mobile phone system.

From the point of view of GSM users, the key advantage of GSM systems has been higher digital voice quality and low cost alternatives to making calls such as text messaging.

Also, like other cellar standards, GSM allows network operators to offer roaming services which means subscribers can use their phones all over the world.

One of the key features of GSM is the subscriber identity module (SIM), commonly known as a SIM card. The SIM is detachable smart card containing the user’s subscription information and phonebook. This allows the user to retain his or her information after switching off the handsets.

Alternatively, the user can also change operators while retaining the handset simply by changing the SIM, some operators will block this by allowing the phone to use only a single SIM  or only a SIM issued by them; this practice is known as SIM locking, and is illegal in some countries.

SUB- TOPIC 6 : FAX MACHINE
Fax (short for facsimile, i.e. “make a copy”) is a telecommunications technology used to transfer copies (facsimiles) of documents, especially using affordable devices operating over the telephone network. The word telefax, short for telefacsimile, for “make a copy at a distance”, is also used as a synonym.

A fax machine is essentially an image scanner, a modem, and a computer printer combined into a highly specialised package. The scanner converts the content of a physical document into a digital image, the modem sends the image data over a phone line, and the printer at the other end, makes a duplicate of the original document.

Fax machines with additional electronic features can connect to computers; can be used to scan documents into a computer, and to print documents from the computer. Such high-end devices are called multifunction printers and cost more than fax machines.

THE TELEPHONE
The telephone is a telecommunication device which is used to transmit and receive sound (most commonly voice and speech) across distance. Most telephones operate through transmission of electric signals over a complex telephone network which allows almost any phone user to communicate with almost any other.

Thus, a telephone is an electric tool. Using a telephone, two people who are in different places can talk. Computer can use a machine called a modem to talk to other computer over a telephone line. This allows a computer to connect to other computer networks including the internet.

MOBILE PHONES
Early telephones needed to be connected with wires. Now telephone calls can be sent with radio. This is also called wireless. While the term “wireless” in this context means radio and can refer to any telephone that uses radio waves, it is primarily used for cellular mobile phones.

Sunday, 15 April 2018

COMPUTER SOFTWARE


Let begin this way, what is a computer? "A computer is an artificial device or machine which is capable of processing data based on what it has been designed for unless been modified." - [Adewale Osunsakin, 2018] Meanwhile, software is the term used to describe computer programs; it is the blood that flows through the computer system. Compared with the hardware, the software used on a given computer is relatively easy to change and it is the attributes, which give computer their flexibility. Just as there are two types of blood cells in human beings performing different functions in the computer system. The first is referred to as System software and the other is the Application software. All other forms of software come under these two board divisions.



Software component of the computer system
Computer hardware without software can be linked to a vehicle without fuel. A system can only perform based on a set of given instructions that are to be followed in sequence, called program. Software refers to the collection of all the programs available on a computer system or in a computer installation. Software can be divided into two main classes namely;
[1] System Software
[2] Application Software

System Software: These are programs written by the manufacturer to ensure the smooth running of the computer. They are programs that enhance the performance operations of computer. It is divided into four classes of the system namely;
1.    Operating system   
2.    Translators
3.    Utilities and service programmers

Examples of Software
Examples of system software includes;
(i) Operating system e.g Disk Operating System(DOS), windows OS, Linux, Unix, Xenix, Ubuntu, Novell Netware, etc
(ii) Translator e.g Compiler, Interpreter, Assemblers
(iii) Utility e.g. Norton utilities, antivirus, scandisk, windows explorer, etc

Application Software:  Application software allows users to accomplish one or more specific tasks. This can be classified into two namely;
1.    User application program
2.  Application Packages
There are various types of application software, this includes;
Word processing software
Spreadsheet software
Database management software
Presentation software
Graphic software
Communication software
Multimedia software

DEFINITION OF AN OPERATING SYSTEM
A set of instruction or programs designed to efficiently manage the resources of the computer system is referred to as operating system. It is the operating system that makes the computer understands the user’s instructions and command. It is the life-wire of a computer system. It does the loading and schedule of all activities going on in a computer system.Also, Operating System can be defined as the collection of programs which are resident in the computer memory. It controls the general operations of the computer system.

Examples of Operating System(OS)
(i) Disk operating system (DOS)
(ii) Windows Operating System
(iii) Linux Operating System
(iv) UNIX
(v) Xenix
(vi) Ubuntu

TYPES OF OPERATING SYSTEM
There are different types of operating system as specified by their operational performance. The most commonly used operating system are:
[1] Single user operating system
[2] Multi user operating system
[3] Networking operating system

Single user operating system allows only a single task performed at a time. It allows a single user to operate the machine time in an interactive mode and allows one user program to be in the main store and processed at a time. It does not allow users program. Examples of a single user operating system includes MSDOS, PCDOS etc.

Multi-User Operating System permits the execution of more than one task at a time. It shares the system resources to more than one user by connecting the individual user on the system. Examples are window 98, windows me, Xenix OS/2, etc.

Networking operating system is used in network environment where users form different locations are interconnected. Computers connected to a large network, such as WAN & INTERNET. Examples of a networking operating system includes window NT, window 2000, window XP, Novel Netware. Etc.

FUNCTIONS OF AN OPERATING SYSTEM
The general functions of the operation system include the following among others.
-1.It helps in loading and scheduling of programs to provide continuous processing and give appropriate response to events
-2.It protects software, hardware and data from improper use.
-3.It manages hardware resources.
-4.It performs the loading of programs from external memory to the main memory.
-5.It provide error correction routine
-6.It makes communication possible between the users and computer system
-7.It passes control from one job to another in a multi programming environment.
-8.It handles interrupts and computer language malfunctioning.

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