References:

http://ee.hawaii.edu/~tep/EE160/Book/chap1/subsection2.1.1.1.html#SECTION0011100000000000000

http://en.wikipedia.org/wiki/Personal_computer_hardware

http://en.wikipedia.org/wiki/Operating_system

http://www.ehow.com/list_5954327_parts-floppy-drive-_amp_-functions.html

http://www.thinkwiki.org/wiki/Error_Codes_and_Beep_Codes

http://www.computerhope.com/beep.htm

http://fcit.usf.edu/network/chap5/chap5.htm

http://www.ianswer4u.com/2011/05/ring-topology-advantages-and.html#ixzz2LF3qhSLc 

http://www.functionx.com/networking/index.htm

COMPUTER FUNDAMENTALS

Computer

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 logical) calculations.

A computer has four functions:

            A. accepts data                           Input

            B. processes data                       Processing

            C. produces output                    Output

            D. stores results                         Storage

Input (Data):

Input is the raw information entered into a computer from the input devices. It is the collection of letters, numbers, images etc.

Process:

Process is the operation of data as per given instruction. It is totally internal process of the computer system.

Output:

Output   is   the   processed   data   given   by   computer   after   data   processing.   Output   is   also called as Result. We can save these results in the storage devices for the future use.

3 Computer Systems

1.     Software

It is a collection of computer programs and related data that provides the instructions for telling a computer what to do and how to do it.

2.     Hardware

The physical machine, consisting of electronic circuits, is called the hardware. It consists of several major units: the Central Processing Unit (CPU), Main Memory, Secondary Memory and Peripherals.

3.     Peopleware

Peopleware can refer to anything that has to do with the role of people in the development or use of computer software and hardware systems, including such issues as developer productivity, teamwork, group dynamics, the psychology of programming, project management, organizational factors, human interface design, and human-machine-interaction.

COMPUTER SOFTWARE

  1.1            System Software

System software is computer software or an operating system designed to operate and control the computer hardware and to provide a platform for running application software.

1.1.1 Operating System (OS)

An operating system (OS) is a collection of software that manages computer hardware resources and provides common services for computer programs. The operating system is a vital component of the system software in a computer system. Application programs require an operating system to function.

                  

1.1.1.1 Real-time

A real-time operating system is a multitasking operating system that aims at executing real-time applications. Real-time operating systems often use specialized scheduling algorithms so that they can achieve a deterministic nature of behavior. The main objective of real-time operating systems is their quick and predictable response to events. They have an event-driven or time-sharing design and often aspects of both. An event-driven system switches between tasks based on their priorities or external events while time-sharing operating systems switch tasks based on clock interrupts.

             

1.1.1.2 Multi-user

A multi-user operating system allows multiple users to access a computer system at the same time. Time-sharing systems and Internet servers can be classified as multi-user systems as they enable multiple-user access to a computer through the sharing of time. Single-user operating systems have only one user but may allow multiple programs to run at the same time.

 1.1.1.3 Distributed

A distributed operating system manages a group of independent computers and makes them appear to be a single computer. The development of networked computers that could be linked and communicate with each other gave rise to distributed computing. Distributed computations are carried out on more than one machine. When computers in a group work in cooperation, they make a distributed system.

1.1.1.4 Embedded

Embedded operating systems are designed to be used in embedded computer systems. They are designed to operate on small machines like PDAs with less autonomy. They are able to operate with a limited number of resources. They are very compact and extremely efficient by design. Windows CE and Minix 3 are some examples of embedded operating systems.

          1.1.2 Language Translator

                   It converts human language into binary language.

          1.1.3 Utility Software

                   Utility Software is a set of programs that manages and maintain computer peripherals and accessories.

1.2 Application Software

This is also known as an application or an app, is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, and graphics software and media players. Many application programs deal principally with documents. Applications may be bundled with the computer and its system software, or may be published separately. In recent years, the abbreviation "app" has specifically come to mean application software written for mobile devices, with the abbreviation in particular representing both the smaller size and smaller scope of the software (i.e. an app whose sole purpose is to display an image representation of the current weather). Apps for mobile devices are also an important way to deliver advertising to the user. Many websites encourage mobile users to download a free app version of the website so that they can receive cut down advertising typically as a row along the bottom of the app as stock mobile web browsers often do not display the adverts available on full size websites.

COMPUTER HARDWARE

2.1 Input Devices

          Input devices allow the user to enter information into the system, or control its operation. Very early computer systems had literal toggle switches that could be tested by running programs as a simple form of user input; modern personal computers have alphanumeric keyboards and pointing devices to allow the user to interact with running software.

Examples: keyboard, mouse, joystick, webcam, image scanner, microphone

2.1.1 Processing Devices

          Processing devices in a computer are responsible for controlling the storage and retrieval of information. The information is processed by the computer processor (CPU), which performs data calculations, data comparisons, and data copying with the information from the processing devices. The CPU then saves that information to the computer memory (RAM).

Today's computers contain multiple processing devices. Any device that deals with the input and output of information does some form of processing on that information, some with more complexity than others. The one processing device that most people think of is the CPU, but devices like the graphics card, computer memory, network card, and others are processing devices as well.

Example: CPU, MpU (Micro processing Unit), McU (Micro controller Unit)

2.1.2 Storage Devices

          Computer data storage, often called storage or memory, refers to computer components and recording media that retain digital data. Data storage is a core function and fundamental component of computers.

Examples: CD, DVD, Pen Drive, Memory Card

2.1.3  Output Devices

          Output devices display information in a human readable form. A program-controlled pilot lamp would be a very simple example of an output device. Modern personal computers have full-screen point-addressable graphic displays and often a printing device to produce paper copies of documents and images.

Examples: monitor, printer, speakers, projector

 

2.1.4 Input/output Devices

          Alternatively referred to as an IO device, an input/output device is a hardware device that accepts inputted information and also has the capability of outputting that information. 

Examples: digital camera, cell phone, all-in-one printer

PARTS OF THE COMPUTER

Motherboard Parts & Functions:

Motherboard is the main printed circuit board.  It contains the buses, or electrical pathways found in a computer. It also accommodates CPU, RAM, expansion slots, BIOS chip, chip set, sockets, internal and external connectors, various ports and the embedded wires that interconnect the motherboard components.

   1.     CPU (Central Processing Unit)/Processor

The CPU executes a program, which is a sequence of stored instructions. Each model of processor has an instruction set, which it executes. The CPU executes the program by processing each piece of data as directed by the program and the instruction set.

  

          2.     CPU Socket

 Sockets are home for your CPU. Several types of socket exist but only 2 of them are really used, and both of them are used by Intel and AMD. The Pin Gray Array (PGA) and the Land Grid Array (LGA).

      

     3.     Memory Slots

     Memory Slots are called memory banks for RAM modules. Each memory bank receives a RAM module designed for a specific pc motherboard.

      

      4.     Chipset

             This is a set of chips; Northbridge and Southbridge which controls the data flow. The Northbridge controls communication between the CPU and RAM memory while the Southbridge manages the communication between the CPU and I/O busses.

    5.     CPU fan and Heat sink

CPU requires a special heat sink and fan unit to operate properly. If this device is not properly secured and operating normally, a modern CPU can reduce itself to a pile of molten silicon in a matter of seconds. The fan that sits atop a heat sink also plays a role in circulating air inside the computer case.

   6.    Complementary Metal Oxide Semiconductor (CMOS)

      The CMOS chip retains settings such as the time, keyboard settings, and boot sequence. It also stores interrupt request lines (IRQ) and input/output (IO) resources that the BIOS uses when communicating with the computer’s device.

         

     7.     PCI (Peripheral Component Interconnect) Slot

It is an expansion bus architecture. The PCI bus transfers data in parallel over a data bus that is either 32 bit or 64 bits wide.

     

     8.     SATA (Serial Advance Technology Attachment)

This is a faster serial drive interface that has replaced PATA. SATA uses slender cables that can be up to 39.4 inches long. Because each SATA device has a direct connection to the SATA controller, it does not have to share a bus with other devices, and therefore it provides greater throughput.

        9.     Ports

          A.    PS/2 – for keyboard and mouse

          B.    USB Port – for devices with 2.0 or 3.0 USB connector

          C.    VGA Port – for monitor

          D.    Parallel Port – for printer

          E.     Ethernet LAN Port – for internet connection

Hard Disk Drive Parts & Function:

Hard drives store the operating system, application, and much of the user data. Hard drives are one of the computer components that suffer from mechanical failures due to wear on the parts. These failures affect the internal portions of the hard drive.

The Platters

o    The platters are the discs of the hard drive where the computer information gets stored. Both sides of the platters store data.

Slider (and Head)

o    The read/write heads write data to the hard disk platters and retrieve information from them. The read/write heads work in a manner similar to the needle on record players or the laser on CDs and DVDs.

Actuator Arm

o    The arms contain the read/write heads. The hard drive controller moves the arms to the correct position on the disk. The arm assembly is comprised of the head sliders, head arms, sliders and actuator.

The Spindle

o    The platters of a hard drive rest on the spindle. The spindle of the hard drive serves the same function as the spindle on a record player---it causes the disks to rotate.

The Spindle Motor

o    The spindle motor causes the spindle to spin and allows the arm actuators to move the arms to the correct position on the hard disk drive.

CMOS MANIPULATION

  

To access an option in the CMOS, use the cursor (arrow) keys to highlight your choice, as shown in Screenshot A. The Enter key will either invoke a sub-menu or open a selection window, as illustrated in Screenshot B. To alter the value associated with the setting you've selected, you'll have to use the plus [+] or minus [-] keys, or another combination such as [Page Up] and [Page down]. From the main menu screen, you'll use this technique to navigate into various sub-menus, some of which may have subordinate menus of their own as well, until you get where you need to go.

Let's take a brief overview look at the various menus in a typical BIOS setup program:

·         In the "Main" or "Standard CMOS Setup" menus, you can set the date and time, and also define the attributes of your hard disks.

·         In the "BIOS Features Setup" menu, you'll work with general settings of all kinds.

·         The "Integrated Peripherals" menu is where you can manage interfaces and auxiliary system functions.

·          

·         The "Power Management Setup" menu is where you go to configure energy saving or power management functions.

·         The "PnP/PCI Configurations" menu permits you to rearrange which interrupts (IRQs) relate to specific PCI expansion cards in your PC. If you don't find these functions identified as such (or something similar) in the Main menu, you'll probably find them under the "Advanced" menu instead.

·         The "Hardware Monitor" menu shows values from system sensors, such as the processor temperature or fan speeds (in RPM). These are normally for the CPU cooler and system fan, but may also be for the power supply or other fans for which the motherboard has sensing hardware.

·         The "Load Setup Defaults" item restores factory default settings, and wipes out any changes you may have already made. This can be especially useful when you've not configured something properly and the results cause problems on your system.

 

Ending A CMOS Session

To end your work in the CMOS Setup program, you must strike the [F10] key, or select the main menu entry that reads "Save & Exit Setup". Sometimes this involves first selecting an "Exit" option, then choosing the "Exit & Save Changes" sub-entry. You will then be presented with a choice between [Y] and [N], where the [Y] key saves your changes and the [N] key discards them. Select one or the other, and you'll exit the CMOS setup.