Topic 3: Computer Laboratory Care and Maintenance Computer Literacy Computer literacy refers to the ability and skills to use the computer. Booting process Booting refers to the process of starting a computer for use. The computer is powered, then it undergoes power on self-test (POST) and finally the operating system is loaded. Types of booting There are two types of computer booting namely: warm booting and cold booting. Warm booting; refers to the process of restarting a computer that is currently on. Cold booting; refers to starting a computer which initially is off. The process of cold booting a computer The system unit is switched on from the power button then the monitor. The computer goes through power on self-test with the help of BIOS (Basic Input-Output system).The operating system is then loaded. The possible ways of warm booting a computer Using the restart / reset button. Press CTRL+ ALT + DEL on the keyboard Using the operating system command Concept of a computer program Computer program refers to a set of computer instructions created using a programming language. Programming is the process of writing computer instructions or statements to enable a computer accomplish a particular task. Programming language is a set of characters and symbols that are used to create a computer instruction. Program syntax refers to a valid sequence or order of writing characters or statements in a programming language. Types of language translator The three common types of language translator include; Assembler, Compiler and Interpreter. Assembler: It is language translator that is used to convert assembly language program to machine code. Compiler: it is a language translator that is used to convert a high level programming language to machine- readable format. It converts the entire code to object code before execution. Interpreter: a language translator that is used to convert high level programming language program to object code. It converts and executes one line of code at a time. Difference between an interpreter and a compiler Interpreter Compiler Does not store the object code in the computer Stores the object code in the computer memory memory Translates and executes a source code one line Translates the entire source code into machine at a time. code before execution. Translates program run at every runtime. Translation is done once at compilation and no additional translation is done at each time. Machine languages and Assembly languages is often referred to as a “low level language” since the code directly manipulates the hardware of the computer. By contrast, high level languages such as “C”, C++, Pascal, COBOL, FORTRAN, ADA and Java are called “compiled languages”. In a compiled language, the programmer writes more general instructions and a compiler (a special piece of software) automatically translates these high level instructions into machine language. Difference between Low level and high level programming languages Low level High level Machine-dependent Machine independent They are executed faster by the CPU since They are not executed faster since their their syntax is closer to Machine architecture. source code must be translated. They are not easy to use and learn. They are user Friendly and are easy to use and learn. Debugging is not easy Debugging is easy They are not portable They are portable A large portion of software in use today is programmed in high level programming language. A good programing language must have the characteristic of highly legible code, easy maintenance of the code, re-usability of code, faster program development, easy identification of errors and debugging. Debugging refers to identifying and removing errors from the computer hardware and software. Some popular interpreted languages include Basic, Visual Basic, Perl, Python, and shell scripting languages such as those found in the UNIX, Linux and MacOS X environment. Starting a program 1. Click start, 2. Point to All programs, then click on the program intended to use. Or Double click of the icon for the program Right Click the icon, select open and then click open Secure Laboratory Environment Computer laboratory Computer laboratory is a room equipped with computing facilities to enable efficient teaching and learning activities to take place. The areas of laboratory security include: Physical Security: This include the burglar proofing of the room with fitting grills on doors, windows and the roof, to deter forceful entry into a computer room. Installation of an intrusion detection alarm system and employing security guards also increases the level of security alertness against theft of computers and accessories. Electric power security: Computers are delicate devices that require providing a stable source of power. To protect the computers from being damaged due to power instabilities such as power surges or under voltage, connect the computer to Uninterruptible Powers Supply (UPS) than connecting it directly to the main electricity supply. Security Cameras: to secure the facility in the computer lab, the use of CCTV cameras for active detection of any removal of computer accessories such as mouse, keyboard, hard disk, RAM can be secured from the control system which monitor and store the video information hence increasing the security alertness. Fire prevention and control equipment: installing fire prevention equipment such as smoke detectors, gas fire extinguishers for putting out fire in case of fire breakout due to short circuit. The first aid boxes should be in place to reduce the risk. Air conditioning: To control dust, dampness and humidity, the computer laboratory should be fitted with good window curtains and air conditioning system that filters dust particles from the air entering the room. Also computers should be covered with dust covers when not in use. Safe use of the laboratory For the safe use of the laboratory, the measure that protects the user while in the computer lab. - All cables should be insulated: to avoid the danger of electric shock to users. - Cables should be laid away: from user paths to avoid tripping on them. - Providing standard furniture: to avoid poor posture, this may lead to strain injury and limb fatigue. - Providing antiglare screens: to avoid eye strain and fatigue caused by over bright cathode ray tube (CRT) monitors. However, modern flat panel displays such as liquid crystal display (LCD) should be used since they do not strain the eye. - The room should be properly ventilated: to avoid dizziness caused by lack of enough oxygen and to allow computers to cool. - Overcrowding: in the computer room is not allowed. This may cause suffocation. Laboratory rules and regulations For safety, security of computer and data, students using the computer laboratory should adhere to the following rules. 1. Do not use any other school administrator computer account (even with the manual bypass or permission). 2. Do not disclose their own network security code for Wi-Fi or attempt to discover any other computer user’s password and configure in your own password. 3. Do not copy, disclose or transfer any of the computer software without permission of the user or the system administrator. 4. Do not use any school computer facilities to violate the terms of any software license agreement, or copyright provisions. 5. Do not copy, rename, change, examine or delete files and information belonging to some other user. 6. Do not deliberately use-computing facilities to harass others, or to interfere with their work for example to send obscene, abusive, threatening or repetitive messages to a user(s). 7. Do not attempt to modify system facilities, illegally obtain extra resources, and degrade the performance of any system. 8. Do not tamper with terminals, microcomputers or any other associated equipment, all faults should be reported to the system administrator. 9. Do not eat or drink around terminals, microcomputers or other computer equipment. 10. Always cover your computers and its peripherals to protect them from damage caused especially by dust and moisture. 11. Always close all the tasks running before shutting down the computer and follow the systematic procedure of shutting down the computer. Servicing and maintenance of computer Systems It is very important to keep your Computers maintained to avoid downtime and the safety of your data/information. The following are some of the ways to maintain your computer. • Cleaning of the computers: physical removal of dirt, dust and debris from the interior or exterior parts of computer peripherals such as keyboard, mouse, monitor and system unit. This can be done by use of a clean soft clothing or compressed air to blow out the debris from the intake slot and fan. • Updating of software: Provides bug fixes for features not working properly and minor software enhancements, and sometimes include new drivers to support printers or DVD drives. A software update is sometimes called a patch because it is installed over current software already in use. This helps to improve performance and safeguard against malware by updating programs e.g. anti-virus and computer programs. • Upgrading software: Is a purchase of a newer version of software for current use. This helps in replacement of older version to the current version which supports various compatibility. • Software installation: • Installation of a computer program is the act of making the program ready for execution. Helps in creating more applications for use and improves the system performance of the computer with various computer programs for use. Fine-tuning the system: Fine tuning refers to the circumstance where the parameter of a model must be adjusted precisely to agree with the observation. Example adjusting the screen resolution and appearance. Importance of Servicing and maintenance of a computer • Detects earlier problems that may cause system start-up errors, hanging applications and warm booting. • Keeping the computer healthy and running smoothly by protecting it from viruses, malware, and spyware that can be difficult to remove and cause computer to run slowly. • Helps to keep the computer clean from dirt, dust and debris. • Helps to keep the computer in a good working condition that can work for a long time with new upgrades and updates which will make the computer work fast.