COMPUTER HARDWARE AND SOFTWARE

COMPUTER HARDWARE :

 Hardware includes all the components of computer which has physical existence. 
Hardware is the physical aspect of computers, telecommunications, and other information technology devices. 

The term arose as a way to distinguish the "box" and the electronic circuitry and components of a computer from the program you put in it to make it do things. 

It includes all the components of computer which has physical existence - not only the computer proper but also the cables, connectors, power supply units, and peripheral devices such as the keyboard, mouse, audio speakers, and printers. 

HARDWARE REQUIREMENTS :

A hardware requirements list is often accompanied by a hardware compatibility list (HCL), especially in case of operating systems. 

An HCL lists tested, compatible, and sometimes incompatible hardware devices for a particular operating system or application. 

The various aspects of hardware requirements:

1. Architecture

  • All computer operating systems are designed for a particular computer architecture. 
  • Most software applications are limited to particular operating systems running on particular architectures. 
  • Although architecture-independent operating systems and applications exist, most need to be recompiled to run on a new architecture. See also a list of common operating systems and their supporting architectures.

2. Processing power

  • The power of the central processing unit (CPU) is a fundamental system requirement for any software. 
  • Most software running on x86 architecture define processing power as the model and the clock speed of the CPU. 
  • Many other features of a CPU that influence its speed and power, like bus speed, cache, and MIPS.
  • AMD Athlon and Intel Pentium CPUs at similar clock speed often have different throughput speeds. Intel Pentium CPUs have enjoyed a considerable degree of popularity, and are often mentioned in this category.

3. Memory

  • All software, when run, resides in the random access memory (RAM) of a computer.
  • Memory requirements are defined after considering demands of the application, operating system, supporting software and files, and other running processes.
  • Optimal performance of other unrelated software running on a multi-tasking computer system is also considered when defining this requirement.

4. Secondary storage

  • Hard-disk requirements vary, depending on the size of software installation, temporary files created and maintained while installing or running the software, and possible use of swap space(if RAM is insufficient).

5. Display adapter

  • Software requiring a better than average computer graphics display, like graphics editors and high-end games, often define high-end display adapters in the system requirements.

6. Peripherals

  • Some software applications need to make extensive and/or special use of some peripherals, demanding the higher performance or functionality of such peripherals. 
  • Such peripherals include CD-ROM drives, keyboards, pointing devices, network devices, etc.


 DIFFERENT HARDWARE PARTS-



  1. Processing Devices :The PC Case , Motherboard, Memory.
  2. Input Devices
  3. Output Devices
  4. The Storage Devices


1. THE PROCESSING DEVICES :

These are the components responsible for the processing of information within the computer system. 
1. THE PC CASE (CPU): 

It is a thin sheet metal enclosure that houses the motherboard, power supply and various drives (HDD, FDD, CD, DVD). 

 A computer case also known as a computer chassis, tower, system unit, cabinet, base unit or simply case and sometimes incorrectly referred to as the "CPU" or "hard drive" is the enclosure that contains most of the components of a computer (usually excluding the display, keyboard and mouse).



2. THE MOTHERBOARD:


It is the main circuit board in a PC. It contains all the circuits and components that run the PC. 


Major Components found on the motherboard are: 

  • CPU - the Central Processing Unit is often an Intel Pentium or Celeron processor. It is the heart of every PC. All scheduling, computation and control occurs here. 

  • BIOS - Basic Input Output System is a non-volatile memory that contains configuration information about the PC. It contains all the code required for the CPU to communicate with the keyboard, mouse video display, disk drives and communications devices. 

    When a PC is powered on it uses the BIOS 'boot code' to set up many required functions that bring the PC to a point where it is ready to work. 

  • RTC - the Real Time Clock chip keeps date, day and time in a 24 hour format just like your watch. The PC uses this clock to 'time stamp' files as they are created and modified. When you print a file it time stamps the pages as they are printed. 

  • Chip Set - these are large chip(s) that integrate many functions that used to be found in separate smaller chips on the motherboard. They save space and cost. 

CONNECTORS IN MOTHERBOARD :

1. Primary Connectors :
    • Power - A 20 pin connector accepts a plug from the power supply. This plug carry DC power to all the circuits on the motherboard.
    • Keyboard - A Mini-din 6-pin (round) connector found at the back of the motherboard is where the keyboard plugs in.
    • Mouse - A Mini-din 6-pin connector found next to the keyboard connector is where the where the mouse plugs in.
    • Display - This connector is not integrated into the motherboard but is included in this list since its function is absolutely necessary. It is a 15-pin, D-shell type connector found on a video card that plugs into the AGP connector of the motherboard (see below).
    • IDE - stands for Integrated Drive Electronics. These are 40 pin connectors that provide a place to connect the ribbon cables from the drives (hard and CD/DVD). All data between the motherboard and the drives is carried in these cables. They are not accessible unless the PC cover is removed.
    • FDD connector - it is similar in function to the IDE connector. It is a 34 pin ribbon connector that carries data between the motherboard and any floppy drive installed in the PC. Not accessible with PC cover on.
    • DRAM - Dynamic Random Access Memory connectors for SIMM and DIMM type memory modules. Not accessible with chassis cover on. 

 2. Serial Connectors 
  • Standard Serial Connector - This connector has been around in PCs since they first appeared. It was originally located on ISA expansion type cards (see below). Today it is an integral part of newer motherboards. It is a 9- pin, D-shell connector that allows you to connect external devices with serial ports to your PC. The maximum data rate is 115 KB/s. 

3. Parallel Connectors 


  • Centronix or Standard Parallel - This connector has been around in PCs since they first appeared. It has 37-pins and is now integrated on new motherboards. It is usually used to connect your printer to the PC and moves data at about 1MB/s. 

  • SCSI - Small Computer System Interface moves data at a maximum of up to 80Mb/s. It not integrated into most PC motherboards. It can be added to a PC as an Expansion card (see below). Some printers and hard disk drives use SCSI interfaces. 

 4. Expansion Card Connectors - 

  • The CPU connects to expansion card connectors through one of the chip set ICs mentioned above. They are located on the motherboard near the rear of the PC. These connectors allow special function cards to plug into and work with the PC. 
  • Before motherboards integrated the serial and centronix connectors they were found on expansion boards that plugged into ISA slots. 
Most PCs have the following expansion connector types: 

    • ISA - Industry Standard Architecture connectors have been around since 1980 and first appeared in the IBM XT PC. This type of slot still appears on some newer motherboards so that older expansion boards can still be used. However, many motherboards no longer have ISA connectors on them. 

    • PCI - Peripheral Component Interconnect is a newer and faster interface that accepts all expansion cards that have a PCI interface. 

    • AGP - Accelerated Graphics Port is a connector that is designed to work with video cards. Your video display plugs into and is controlled by one of these video cards. Many modern video cards offer enhanced 3D-graphics and fast, full motion video.

2. INPUT DEVICES :

 Input devices are hardware devices which take information from the user of the computer system, convert it into electrical signals and transmit it to the processor. 

 The primary function of input devices is to allow humans to interact with the computer system.

  1. Keyboard 
  2. Mouse 
  3. Joy Stick 
  4. Light pen 
  5. Track Ball 
  6. Scanner 
  7. Graphic Tablet 
  8. Microphone
  9. Magnetic Ink Card Reader(MICR) 
  10.  Optical Character Reader(OCR)
  11. Bar Code Reader 
  12. Optical Mark Reader(OMR)

1. Keyboard 
  • It is the most common and very popular input device which helps in inputting data to the computer. 
  • The layout of the keyboard is like that of traditional typewriter, although there are some additional keys provided for performing additional functions.
  • Keyboards are of two sizes 84 keys or 101/102 keys, but now keyboards with 104 keys or 108 keys are also available for Windows and Internet.


2. Mouse 
  • It is most popular pointing device. 
  • It is a cursor-control device having a small palm size box with a round ball at its base which senses the movement of mouse and sends corresponding signals to CPU when the mouse buttons are pressed.
  • Generally it has two buttons called left and right button and a wheel is present between the buttons.
  • Mouse is used to control the position of cursor on screen, but it cannot be used to enter text into the computer.

3. Joystick

  • It is also a pointing device which is used to move cursor position on a monitor screen.
  • It is a stick having a spherical ball at its both lower and upper ends. The lower spherical ball moves in a socket. 
  • The joystick can be moved in all four directions.
  • The function of joystick is similar to that of a mouse. It is mainly used in Computer Aided Designing(CAD) and playing computer games.


4. Light Pen

  • Light pen is a pointing device which is similar to a pen. 
  • It is used to select a displayed menu item or draw pictures on the monitor screen. 
  • It consists of a photocell and an optical system placed in a small tube.
  • When the tip of a light pen is moved over the monitor screen and pen button is pressed, its photocell sensing element detects the screen location and sends the corresponding signal to the CPU.


5.Track Ball

  • Track ball is an input device that is mostly used in notebook or laptop computer, instead of a mouse.
  • This is a ball which is half inserted and by moving fingers on ball, pointer can be moved. 
  • Since the whole device is not moved, a track ball requires less space than a mouse.
  • A track ball comes in various shapes like a ball, a button and a square.


6. Scanner

  • Scanner is an input device which works more like a photocopy machine. 
  • It is used when some information is available on a paper and it is to be transferred to the hard disc of the computer for further manipulation. 
  • Scanner captures images from the source which are then converted into the digital form that can be stored on the disc. These images can be edited before they are printed.


7. Graphic Tablet

  • Graphic tablet also known as Digitizer is an input device which converts analog information into digital form. 
  • Digitizer can convert a signal from the television or camera into a series of numbers that could be stored in a computer. 
  • They can be used by the computer to create a picture of whatever the camera had been pointed at.
  • Digitizer is also known as Tablet or Graphics Tablet because it converts graphics and pictorial data into binary inputs. 
  • A graphic tablet as digitizer is used for doing fine works of drawing and image manipulation applications.

8.Microphone

  • Microphone is an input device to input sound that is then stored in digital form. 
  • It is used for various applications like adding sound to a multimedia presentation or for mixing music.


9. Magnetic Ink Card Reader(MICR)

  • MICR (magnetic ink character recognition) is a technology used to verify the legitimacy or originality of paper documents, especially checks. Special ink, which is sensitive to magnetic fields, is used in the printing of certain characters on the original documents.
  • Magnetic Ink Character Recognition Code (MICR Code) is a character-recognition technology used mainly by the banking industry to ease the processing and clearance of cheques and other documents.
  • MICR input device is generally used in banks because of a large number of cheques to be processed every day.The bank's code number and cheque number are printed on the cheques with a special type of ink that contains particles of magnetic material that are machine readable.
  • The main advantages of MICR is that it is fast and less error prone.


10. Optical Character Reader(OCR)

  • OCR is an input device used to read a printed text.
  • OCR scans text optically character by character, converts them into a machine readable code and stores the text on the system memory.


11. Bar Code Readers

  • Bar Code Reader is a device used for reading bar coded data (data in form of light and dark lines).
  • Bar coded data is generally used in labelling goods, numbering the books etc.
  • It may be a hand held scanner or may be embedded in a stationary scanner. 
  • Bar Code Reader scans a bar code image, converts it into an alphanumeric value which is then fed to the computer to which bar code reader is connected.



12. Optical Mark Reader(OMR)

  • OMR is a special type of optical scanner used to recognize the type of mark made by pen or pencil.
  • It is used where one out of a few alternatives is to be selected and marked. 
  • It is specially used for checking the answer sheets of examinations having multiple choice questions.

3. OUTPUT  DEVICES:

 These take data from the computer system and convert it to a form that can be interpreted by humans. 
  1. Monitor
  2. Printers (all types)
  3. Plotters
  4. Projector
  5. Speaker(s)
  6. Headphones

1. Monitor 
  • It is also known as a display is an electronic visual display for computers. 
  • The monitor comprises the display device, circuitry and an enclosure.
  • The display device in modern monitors is typically a thin film transistor liquid crystal display (TFT-LCD) thin panel, while older monitors used a cathode ray tube (CRT) about as deep as the screen size.

2. Printer 
  • It is a peripheral which makes a persistent human readable representation of graphics or text on paper or similar physical media.
  • The two most common printer mechanisms are black and white laser printers used for common documents, and color inkjet printers which can produce high quality photograph quality output.

3. The plotter 
  • It is a computer printer for printing vector graphics. 
  • In the past, plotters were used in applications such as computer-aided design, though they have generally been replaced with wide-format conventional printers. 
  • A plotter gives a hard copy of the output. It draws pictures on a paper using a pen. 
  • Plotters are used to print designs of ships and machines, plans for buildings and so on.


4. A projector 
  • Image projector is an optical device that projects an image (or moving images) onto a surface, commonly a projection screen.
  • Most projectors create an image by shining a light through a small transparent lens, but some newer types of projectors can project the image directly, by using lasers. 
  • A virtual retinal display, or retinal projector, is a projector that projects an image directly on the retina instead of using an external projection screen.
  • Example- Video projectors are digital replacements for earlier types of projectors such as slide projectors and overhead projectors. These earlier types of projectors were mostly replaced with digital video projectors throughout the 1990s and early 2000s (decade), but old analog projectors are still used at some places. 
  • The newest types of projectors are handheld projectors that use lasersor LEDs to project images. Their projections are hard to see if there is too much ambient light.
  • Movie theaters use a type of projector called a movie projector. Another type of projector is the enlarger, a device used to produce photographic prints from negatives.
5. Computer speakers

  • Multimedia speakers, are speakers external to a computer, that disable the lower fidelity built-in speaker. 
  • They often have a low-power internal amplifier.
  • Features vary by manufacturer, but may include the following:

  1.            An LED power indicator.
  2.            A 3.5 mm headphone jack.
  3.            Controls for volume, and sometimes bass and treble.
  4.          A remote volume control or a device that uses the similar             function of mouse scrolling for adjusting the volume.
6. Headphones 
  • These are a pair of small loudspeakers that are designed to be held in place close to a user's ears.
  • They are electroacoustic transducers, which convert an electrical signal to a corresponding sound in the user's ear. 
  • Headphones are designed to allow a single user to listen to an audio source privately, in contrast to a loudspeaker, which emits sound into the open air, allowing anyone nearby to listen. 
  • Headphones are also known as earspeakers, earphones or, colloquially, cans. 
  • TYPES -Circumaural and supra-aural headphones use a band over the top of the head to hold the speakers in place. The other type, known as earbuds or earphones consist of individual units that plug into the user's ear canal. 
  • In the context of telecommunication, a headset is a combination of headphone and microphone.
  • Headphones either connect directly to a signal source such as an audio amplifier, radio, CD player, portable media player, mobile phone, video game consoles, electronic musical instrument, or use wireless technology such as bluetooth or FM radio.


COMPUTER SOFTWARE :


Software is a set of instructions for a computer to perform specific operations.


SOFTWARE REQUIREMENTS :

Software requirements deal with defining software resource requirements and prerequisites that need to be installed on a computer to provide optimal functioning of an application.

 These requirements or prerequisites are generally not included in the software installation package and need to be installed separately before the software is installed.


1. Platform

  • A computing platform describes some sort of framework, either in hardware or software, which allows software to run.
  • Typical platforms include a computer's architecture, operating system, or programming languages and their runtime libraries.
  • Operating system is one of the requirements mentioned when defining system requirements (software). 
  • Software may not be compatible with different versions of same line of operating systems, although some measure of backward compatibility is often maintained. 
  • For example, most software designed for Microsoft Windows XP does not run on Microsoft Windows 98, although the converse is not always true. 
  • Similarly, software designed using newer features of Linux Kernel v2.6 generally does not run or compile properly (or at all) on Linux distributions using Kernel v2.2 or v2.4.


2. APIs and drivers

  • Software making extensive use of special hardware devices, like high-end display adapters, needs special API or newer device drivers. 
  • Example - DirectX, which is a collection of APIs for handling tasks related to multimedia, especially game programming, on Microsoft platforms.


3. Web browser

  • Most web applications and software depending heavily on Internet technologies make use of the default browser installed on system.
  • Microsoft Internet Explorer is a frequent choice of software running on Microsoft Windows, which makes use of ActiveX controls, despite their vulnerabilities.

4. Other requirements

Some software also has other requirements for proper performance. Internet connection (type and speed) and resolution of the display screen are notable examples.

Example

For instance, while StarCraft (1998) requires:

System Requirements

Windows
Operating systemWindows 95 or NT or superior
CPUPentium processor at 90 MHz or higher
Memory16 MB RAM
Hard drive80 MB available in the hard disk
MediaCD-ROM, 2x or higher
Graphics hardwareDirectX 3.0 or higher


TYPES OF SOFTWARE :


1. System software

It is the software used to manage and control the hardware components and which allow interaction between the hardware and the other types of software. 

 Types of system software:
1. Operating System Software (O.S) : It is a program designed to run other programs on a computer. A computer's operating system is its most important program. It is considered as the backbone of a computer managing both software and hardware device. Operating systems are responsible for each and everything from the control and allocation of memory to input from external devices and output to computer display.

An operating system also plays a vital role in security. Its job includes preventing unauthorized user from accessing the computer system

There various types of operating system are -
  • General Purpose O.S
  • Special Purpose O.S
  • Batch Processing O.S
  • Single Use O.S
  • Multi-User O.S
  • Multi-Programming O.S
  • Multi-Processing O.S
  • Multi-Threading O.S
  • Real Time O.S
  • Embedded O.S



2. Language Translator :

It is another system software which convert the high level language to machine level language for the purpose of machine understanding.

The Machine can only understand the machine level language or binary language 0's & 1's. The language translator rectify the errors within the program through different ways.

There are 3 types of language translator, they are as follows :-
  • Compiler.
  • Interpreter.
  • Assembler.
2.Applications software 

 It also known as 'apps' are designed to allow the user of the system complete a specific task or set of tasks. 

 Application software (an application) is a set of computer programs designed to permit the user to perform a group of coordinated functions, tasks, or activities.

 Application software cannot run on itself but is dependent on system software to execute. 

 Examples - 

  • A word processor, 
  • A spreadsheet design  
  • Management system, 
  • An aeronautical flight simulator, 
  • A console game, 
  • A drawing, painting, and illustrating system, or a library management system.


 They include programs such as web browsers, office software, games and so on. 

TYPES OF APPLICATION SOFTWARE ;
  • An application suite consists of multiple applications bundled together. They usually have related functions, features and user interfaces, and may be able to interact with each other, e.g. open each other's files. Business applications often come in suites, e.g. Microsoft Office, LibreOffice and iWork, which bundle together a word processor, a spreadsheet, etc.; but suites exist for other purposes, e.g. graphics or music.
  • Enterprise software addresses the needs of an entire organization's processes and data flows, across several departments, often in a large distributed environment. Examples include enterprise resource planning systems, customer relationship management (CRM) systems and supply chain management software. Departmental Software is a sub-type of enterprise software with a focus on smaller organizations and/or groups within a large organization. (Examples include travel expense management and IT Helpdesk.)
  • Enterprise infrastructure software provides common capabilities needed to support enterprise software systems. (Examples include databases, email servers, and systems for managing networks and security.)
  • Information worker software lets users create and manage information, often for individual projects within a department, in contrast to enterprise management. Examples include time management, resource management, analytical, collaborative and documentation tools. Word processors, spreadsheets, email and blog clients, personal information system, and individual media editors may aid in multiple information worker tasks.
  • Content access software is used primarily to access content without editing, but may include software that allows for content editing. Such software addresses the needs of individuals and groups to consume digital entertainment and published digital content. (Examples include media players, web browsers, and help browsers.)
  • Educational software is related to content access software, but has the content and/or features adapted for use in by educators or students. For example, it may deliver evaluations (tests), track progress through material, or include collaborative capabilities.
  • Simulation software simulates physical or abstract systems for either research, training or entertainment purposes.
  • Media development software generates print and electronic media for others to consume, most often in a commercial or educational setting. This includes graphic-art software, desktop publishing software, multimedia development software, HTML editors, digital-animation editors, digital audio and video composition, and many others.
  • Product engineering software is used in developing hardware and software products. This includes computer-aided design (CAD), computer-aided engineering (CAE), computer language editing and compiling tools, integrated development environments, and application programmer interfaces.
  • Entertainment Software can refer to video games, screen savers, programs to display motion pictures or play recorded music, and other forms of entertainment which can be experienced through use of a computing device.

3.Utility software 

 It is software such as anti-virus software, firewalls, disk defragmenters and so on which helps to maintain and protect the computer system but does not directly interface with the hardware.
Example -

 Antivirus:- Utility scan for computer virus.
                  - Memory tester check's for memory failure etc.

The following are the activities those are coming under the utility software are -
  • Formatting.
  • Back-Up Recovery.
  • Disk Defragmenter.
  • Registry Cleaners.
  • Disk Partitions. Etc