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COURSE CODE: CMP 111
COURSE TITLE: INTRODUCTION TO COMPUTER
NUMBER OF UNITS: 3 Units COURSE DURATION: Three hours per week
COURSE LECTURER: JOHN TEMITOPE OGBITI
INTENDED LEARNING OUTCOMES
At the completion of this course, students are expected to:
- Define the concept of Computer
- History of Computer and generations of computer
- Understand the characteristics of a computer, classes of computer, types of computer and functions of personal computers
- Components of a Personal Computer and categories of an operating system
- Principles of Networking
- Program development: algorithms and methods of representing algorithms
COURSE DETAILS:
Week 1-2: Introduction to computer History and generations of computers Week 3-5 : the characteristics of a computer, classes of computer, types of computer and functions of personal computers Week 6-8 : Components of a Personal Computer and categories of an operating system Week 9-10 Principles of Networking: computer network, topology, Internet and Benefits of the Internet Week 11: Program development: algorithms and methods of representing algorithms concept of algorithms: flowcharts and pseudo code
Week 12 Revision
RESOURCES
- Lecturer’s Office Hours:
- Mr. John Temitope Ogbiti, Monday 1-2pm,
- Course lecture Notes: http://www.edouniversity.edu.ng/oer/compsc/cmp111.pdf
- Introduction to Computer science, A text book for beginners I Informatics by Gilbert Brands.
- Introduction to Computer science, by Thomas J. Cashman.
- Exams:
- Final, comprehensive (according to university schedule): ~ 70% of final grade Assignments & Grading
- Academic Honesty: All classwork should be done independently, unless explicitly stated otherwise on the assignment handout.
- You may discuss general solution strategies, but must write up the solutions yourself.
- If you discuss any problem with anyone else, you must write their name at the top of your assignment, labeling them “collaborators”.
- NO LATE HOMEWORKS ACCEPTED
- Turn in what you have at the time it‟s due.
- All home works are due at the start of class.
- If you will be away, turn in the homework early.
INTRODUCTION The computer is fast becoming the universal machine of the twenty-first century. Early computers were large in size and too expensive to be owned by individuals. Thus they were confined to the laboratories and few research institutes. They could only be programmed by computer engineers. The basic applications were confined to undertaking complex calculations in science and engineering. Today, the computer is no longer confined to the laboratory. Computers, and indeed, computing have become embedded in almost every item we use. Computing is fast becoming ubiquitous. Its application in engineering, communication, space science, aviation, financial institutions, social sciences, humanities, the military, transportation, manufacturing, the extractive industries to mention but a few. Definitions Computer is an advanced electronic device that takes raw data as input from the user and processes these data under the control of set of instructions (called program) and gives the result (output) and saves output for the future use. It can process both numerical and non-numerical (arithmetic and
supercomputer and are pervasive throughout society. Therefore, this brief sketch of the development of scientific co mp u t i n g i s limited to the area of digital, electronic computers.
The evolution of digital computing is often divided into generations. Each generation is characterized by dramatic improvements over the previous generation in the technology used to build computers, the internal organization of computer systems, and programming languages. Although not usually associated with computer generations, there has been a steady improvement in algorithms, including algorithms used in computational science. The following history has been organized using these widely recognized generations as mileposts.
The First Generation (1946^ –^ 1958)
- The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms.
- They were very expensive to operate and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions
- First generation computers relied on machine language, the lowest-level programming language understood by computers, to perform operations and they could only solve one problem at a time.
- Input was based on punched cards and paper tape, and output was displayed on printouts
Vacuum tube
The Second Generation (1959^ –^ 1964)
- Transistors replaced vacuum tubes and ushered in the second generation of computers.
- One transistor replaced the equivalent of 40 vacuum tubes
- Allowing computers to become smaller, faster, cheaper, more energy- efficient and more reliable
- Still generated a great deal of heat that can damage the computer.
- Second-generation computers moved from cryptic binary machine language to symbolic, or assembly, languages, which allowed programmers to specify instructions in words
- Second-generation computers still relied on punched cards for input and printouts for output.
- These were also the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology
Transistor
The Third Generation (965^ –^ 1970)
- The development of the integrated circuit was the hallmark of the third generation of computers.
- Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers.
- Much smaller and cheaper compare to the second generation computers.
- It could carry out instructions in billionths of a second.
- Users interact with third generation computers through keyboards and monitors and interfaced with an operating system, which allowed the
Computer Generations and Their Characteristics
CHARACTERISTICS OF A COMPUTER
- Speed: The computer can manipulate large data at incredible speed and response time can be very fast.
- Accuracy: Its accuracy is very high and its consistency can be relied upon. Errors in computing are mostly due to human rather than technological weakness. There is in-built error detecting schemes in the computer.
- Storage: It has both internal and external storage facilities for holding data and instructions. This capacity varies from one machine to the other. Memories are built up in K (Kilo) modules where K= memory locations.
- (^) Automatic: Once a program is in the computer‟s memory, it can run automatically each time it is opened. The individual has little or no instruction t o give again.
- Reliability: Being a machine, a computer does not suffer human traits of tiredness and lack of concentration. It will perform the last job with the same speed and accuracy as the first job every time even if ten million jobs are involved.
- Flexibility: It can perform any type of task once it can be reduced to logical steps. Modern computers can be used to perform a variety of functions like on-line processing, multi-programming, real time processing e.t.c.
CLASSES OF COMPUTER
- Analog Computers: This class of computer are special purpose machines that surfaced in the late forties (1948). They are used solving scientific and mathematical equations or problems. An example is the thermal analyzer. Data and figures are represented by physical quantities such as angular positions and voltage.
- Digital Computers: They are machines made up of combinations of chips, flip-flops, buttons and other electronic devices to make them function at a very fast speed. A digital computer has its numbers, data letters or other symbols represented in digital format. They are mostly special purpose machines unless minor specifications are included in the design.
- A computer that combines the features of a digital and analog computer is called a hybrid computer.
TYPES OF COMPUTER
Super Computers
- A super computer is the most powerful computer available at any given time. These machines are built to process huge amounts of information and do so very quickly.
- Supercomputers are built specifically for researchers or scientists working on projects that demand very huge amounts of data variables; an example is in nuclear research, where scientists want to know exactly what will happen during every millisecond of a nuclear chain reaction. (To demonstrate the capability of super computers, for an air pollution control project that involves more than 500,000 variables, it will take a mini
central processing unit (CPU) of workstations are designed differently to enable faster processing of instructions and most of the micro computers can run any of the four major operating systems.
- Workstations [(Reduced Instruction Set Computing (RISC)] use UNIX operating system or a variation of it. (A note of caution: Many people use the term workstation to refer to any computer or terminal that is connected to another computer. Although this usage was once a common meaning of the term, it has become out dated) (The biggest manufacturers of workstations are Sun Microsystems).
Micro Computers/Personal Computers
- The term microcomputers and personal computers are used interchangeably to mean the small free- standing computers that are commonly found in offices, homes and classrooms.
- Many micro computers are built specially to be used in watches, clocks, and cameras. Today, PCs are seriously challenging mainframes and mini computers in many areas. In fact today PCs are more powerful than mainframes of just a few years ago, and competition is producing smaller, faster models every year.
TYPES OF PERSONAL COMPUTERS
- THE DESKTOP: This is the first type of PCs and the most common. Most desktops are small enough to fit on a desk, but are a little too big to carry around.
- THE LAPTOP: They weigh about 10pounds (4.5kg). They are battery – operated computers with built–in screens. They are designed to be carried and used in locations without electricity. Laptops typically have an almost full – sized keyboard.
- THE NOTEBOOK: They are similar to laptops and PCs, but smaller. They weigh about 6 to7 pounds (2.7 – 3.2kg). As the name implies, they are approximately the size of a notebook and can easily fit inside a brief case.
- THE PALMTOP: They are also known as personal digital assistance (PDAs) and are the smallest of portable computers. Palmtops are much less powerful than notebooks or desktops models and feature built-in
applications such as word processing. They are mostly used to display important telephone numbers and addresses.
FUNCTIONS OF PERSONAL COMPUTERS
Personal computers can do a lot of things. The most common tasks computers perform include:
- Writing documents such as memos, letters, reports and briefs
- Budgeting and performing accounting tasks
- Analyzing numeric information
- Searching through lists or reports for specific information
- Scheduling and planning projects.
- Creating illustrations
- Communicating by using electronic mail
- Advertising products and services.
COMPONENTS OF A PERSONAL COMPUTER
A personal computer is not a single unit. A typical computer consists of several basic parts or components that work together. To perform any computer task you need two major components: the hardware and the software. [1] The hardware is the physical components of a computer system. Generally you can think of the hardware as any part of the computer that you can see or touch. Although the hardware of a computer is capable of performing marvelous tasks, it cannot accomplish any of them without the vital instructions that the software provides. [2] The software is a set of instructions that tells the hardware what to do. You can‟t see or touch the software, although you can see packages that contain the software. It is typically distributed on CD-ROM disc and is installed on the computer hard drive.
HARDWARE COMPOINENTS
The major hardware components of the personal computer consist of the following: [1] Input Devices : Input devices are the computer hardware that accepts data and instructions from a user. Input devices have been built in many forms to help in communicating with the computer. The most common input devices are the keyboard and the mouse.
viii. The Bar-Code Reader: This is one of the most commonly used input devices after the keyboard and mouse. It is commonly found in supermarkets and department stores. This device converts a pattern of printed bars on products into a product number by emitting a beam of light frequently from a laser that reflects off the bar code image. A light sensitive detector identifies the bar-code image by special bars at both ends of the image. Once it has identified the barcode, it converts the individual bar patterns into numeric digits.
Input Devices
[2] Processing Devices: Basically two components handle processing in a computer: the central processing unit (CPU) and the memory.
a. The Central Processing Unit (CPU) : The central processing unit (CPU) is a tiny electronic chip known as the micro processor located in the system unit. It is installed on the main circuit board of the computer, the motherboard. The CPU as the name implies is where information is processed within the computer. In this regard, you might think of the CPU (processor) as the brain of the computer. The CPU is otherwise known as microprocessor. Every CPU has at least two basic parts. The control unit and the Arithmetic Logic Unit (ALU). The control unit coordinates all the computer activities and contains the CPUs instruction to carry out commands. The ALU is responsible for carrying out arithmetic and logic functions. In other words, when the control unit encounters an instruction that involves arithmetic and logic it refers it to the ALU. b. Memory: What happens to all the information we put into the computer: before, while and after information is processed? It is held in the computer memory or Random Access Memory (RAM). The memory to which we are referring here is not the kind of long-term storage that allows you to save work on a floppy disk and months later to use it, but rather a short term holding area that is built into the computer hardware. While the CPU is fast and efficient, it cannot remember anything by itself. It often refers to the memory in the computer for software instruction and to remember what it is working on. The term RAM and memory are often interchangeable. RAM refers to the way the CPU searches through memory for the information it needs. For the workings of a memory, information is stored in memory chips. The CPU can get information faster from RAM than it can from a disk. A computer then reads information or instruction from disks and stores the information in the RAM where it can get the information quickly. The CPU processes the information and then returns to the RAM.
Central Processing Unit (CPU Memory
removable cartridges or disk. A zip drive holds about 100MB to 250 MB of Data.
Storage Devices
[4] Output Devices: Output devices return processed data, that is, information back to the user. In other words, output devices allow the computer „talk‟ to us. The most common output devices are the monitor and the printer. Others include modems and speakers. a. The Monitor: The monitor is an output device that enables the computer to display to the user what is going on. It has a screen like that of a television. It is commonly referred to as the screen or display. It is the main source for output of information from the computer. As data is entered through an input device, the monitor changes to show the effects of the command. Messages displayed on the screen allow the user to know if the command is correct. b. The Printer : The printer is an output device that produces on hard copy or a print out on a paper i.e. it takes data from its electronic form and prints it out on paper. There are three principal types of printers; Laser, Inkjet and Dot – Matrix.
c. The Sound Card: Sound Cards, otherwise known as sound boards, is a hard ware board. It is a device that produces audio sounds and usually provides ports in the back of a computer for external speakers. It is installed in one of the expansion slot inside the system unit‟s motherboard. d. The Modem: The modem is a device that allows a computer to communicate with another computer through a telephone line. Both computers need compatible modem. With a modem, a computer and required software, you can connect with other computers all over the world. Output Devices
SOFTWARE COMPOINENTS
Software is a set of instructions that operate a computer, manipulate the data and execute particular functions or tasks. In other words, it is a programs, routines, and symbolic languages that control the function of the hardware. For software (the instructions) to perform various functions, it must be programmed. That is, the instructions need to be written in a programming language that the computer can understand. Without a program, a computer is useless.
must have an operating system in order to run other programs. This includes controlling functions such as the coordination of the hardware and applications software, allocating storage facilities, controlling the input and output devices and managing time sharing for linked or networked computers.
FUNCTIONS OF AN OPERATING SYSTEM
- Booting of Computer: This is the first process which takes place the moment the computer's electrical switch is put on. During this process all the peripherals connected to the computer are checked and validated; at the end of the validation process, the OS signals the user to begin working on the computer.
- Providing User Interface: The OS provides an interface for the user, either as a command line interface or as a graphical user interface. This enables the user to communicate with the computer.
- Managing the Hardware: OS controls and manages hardware resources. For example, OS manages the selection and operation of devices used for input, output and storage. In other words the OS serves as the intermediary between programs and hardware.
- Managing the File System: The operating system groups‟ data together into -logical compartments for storage on disk. These groups of data are called files. The computer stores information in files. Files may contain program instructions or data created or used by a program. The OS maintains the list of files on a disk.
- Supporting Programs: Another major function of an OS is to provide services to other programs. Often these services are similar to those that the OS provides directly to users. For example when you want your word- processing program to retrieve a document, the word processor will list the files in the directory that you specify.
- Some of the other services that an OS provides to programs are: saving files to disk reading them from disk into memory checking available disk or memory space allocating memory to hold data for a program
CATEGORIES OF AN OPERATING SYSTEM
- Multitasking the Operating System/Multi Programming: This is an OS that is able to run more than one program task per operation time.
There are two types of multitasking operating systems cooperative and preemptive.
- Cooperative Multitasking: This requires cooperation between the OS and application programs. In this case the programs are written in such a way that they periodically check with the OS to see whether any other program needs the CPU. If a program needs the CPU, they relinquish control of the CPU to the next program. Cooperative multitasking is common with Macintosh OS and DOS computers running Microsoft Windows.
- Preemptive Multitasking: Under this scheme, the OS maintain a list of processes (programs) that are running. Each process on the list is assigned a priority by the OS when it is started. At any time, the OS can intervene and modify the priority list. The OS also retains control of the amount of time that it spends with any process before going to the next process. UNIX, OS/2 and Windows NT employ preemptive multitasking.
- Multi-user Operating Systems: A multi-user OS allows more than a single user access to a computer at the same time. Of course, to accomplish this, a multi-user OS must also be capable of multitasking. Only UNIX OS and Windows NT are capable of supporting multiple users. UNIX provides three ways to let people use the same PC at the same time.
- The first way to connect to a PC running UNIX is from another computer with a modem. The remote user can log in and run programs, list files, send e-mails read the news and otherwise do everything they could do if they were physically in front of the UNIX computer.
- The second way to connect to a UNIX computer is by attaching terminals to the PC. Terminals are inexpensive devices that consist of a keyboard, and a monitor.
- The third way to tap into a UNIX computer multi-user capabilities is with a network.
- Multiprocessing Operating Systems: A special type of OS is required to use a computer equipped with more than one CPU. In other words, multiprocessing requires an OS capable of using and managing a series of CPUs. There are two types:
