Keyboard - 101 keys, Alphanumeric key, Punctuation keys, Special keys, Arrow keys, etc. Mouse

1. 
   Track Balls, Joystick
   

1. 
   Track Ball - Pointer mover by your palm, or thumb press.
   
2. 
   Joystick - Pointer mover leaver with two buttons (Triggers).
   

3. 
   Scanner - It can read text and pictures to convert it into digitals form and store to print them. It can print 600 dots per inch quality text or Images. There is single color or multiple colored scanners. There are half or full page scanner.
   

4. 
   Digital Camera - It can manipulate, save, delete, and rotate the images. It sends as digitals input files to the computer.
   

1. 
   OMR, MICR, OCR, Bar Code Reader
   

1. 
   Optical Mark Reader (OMR): OMR is also called mark sensing, which is a technology. It can sense the presence or absence of the pencil mark. OMR is used in the aptitude texts.
   

2. 
   Optical character Reader (OCR): It reads the page of text and converts images into ASC II codes to store into the computer. In the future it can print ditto for the user. All OCR system includes an optical scanner. It enables to take a book and save into a computer file.
   
3. 
   Bar code Reader: Bar code reader is a photoelectric scanner that reads the bar code (Vertical Zebra Striped marks,) printed on the product. In the supermarket, you can find bar codes in ever items.
   

4. 
   Magnetic ink character Reader (MICR): MICR is direct entry method used in the banks. It is a special type of input device used in ATM.
   

6. 
   Speech Input Devices: It is a type of device that allow a person to input data to a computer system by speaking to it.
   

1. 
   Touch Screen, Touch Pad
   

1. 
   Touch Screen: - It is a type of display screen that has the touch sensitive transparent panel covering the screen. As a mouse pointer, you can use your finger on screen.
   
2. 
   Touch Pad: - On a portable PC you can find a small touch pad where you can use your finger along the pad.
   

1. 
   Light Pen, Digitizing tablet
   

1. 
   Light Pen: - It is special pen, which uses light sensitive defector too select object on the screen display. This pen is also similar to mouse.
   
2. 
   Digitizing tablet - It is an electronic tablet. A stylus pen is used here to draw pictures and to operate computer. They are called touch tablet
   

2. 
   Output Devices:
   

1. 
   Monitor and Its Types
   

(ii) Flat type monitors (LCD): Liquid Crystal Display

1. 
   Characteristics, Size, Bandwidth of a Monitor:-
   

1. 
   Size = 14", 15", 17", 24"
   
2. 
   Resolution= how densely pixels are packed?
   

2. 
   Printer and its Types:
   

1. 
   Impact printer: uses letter headed hammer, ink ribbon, paper : Dot matrix & Line printer, Drum, Chain /Band printer
   
2. 
   Non- impact printer- Ink-jet, Laser, LCD printer, Thermal printer
   

1. 
   Ink jet printer- Ionized ink spray, qualify print, diff. fonts.
   
2. 
   Laser printer - Utilizes a laser beam to produce image on the drum. 1200-2400 dpi quality.
   
3. 
   LCD & Led printer - Uses liquid crystal to produce image. Uses light emitting diodes produce image.
   
4. 
   Line printers - It is a high speed printer 3000 lines/min. It can print only font. No pictures.
   
5. 
   Thermal printer - Produces images by trashing electrically heated pins against special paper.
   
6. 
   Plotters - It draws only pictures using pen with continuous lines. Multi color plotters use different colored pens. They are used in the engineering applications.
   
7. 
   Sound cards & speakers - Sound card is compulsory in the modem computers where speakers are used. Sound card enables the computer to output sound, to record input from a microphone connected to the computer and manipulate sound stored on a disk. Sound card translate digital data into analog sounds.
   

2. 
   Computer Software:
   

5. 
   Introduction,
   

1. 
   System software: The software required executing users program is known as system software. It helps to improve the interface between the user and the computer. It includes operating system and utilities software that enables computer to functions. Computer cannot be operated without system software. The system software includes;
   

- Language processors (assemblers, compilers, debugged) and

- Utility programs

2. 
   Application software: The software, which is used to perform specific job, is called application software. This software is available for applications, which are common to many users and organizations. It includes programs, which do real job for the user. An application program is a computer program which installed on computers to give users ability to do specific task. For examples word processing, spreadsheet, DBMS and other end user made programs. There various types of application software/program.
   

1. 
   Operating System (OS):- It is a must to run a computer. OS performs basic tasks like recognizing impact from keyboard, sending output to display screen, keeping tracks o files and directories on the disk. Most commonly used OS are MS-Windows, DOS, XENIX, Mac OS, OS/2, UNIX, MVS etc. There are single user and multi-user operating systems.
   

2. 
   Language processors: the program translated by the language processor is understood by the hardware of the computer. It translates the program written in a programming language into an executable program. These are
   

Some time compiler and interpreters are called language translator programs.

3. 
   Utilities: - the software that provides additional facilities to the user is called utility program. It performs very specific tasks, usually related to managing disk drives, printers and other devices, sorting or margin is done. A call up programs by OS. Transferring data from one I/O devices to another. Disk repair, data copy, data move, virus scan etc are utility program
   

1. 
   Word processing: - Creating, editing, formatting, previewing coloring line text, designing, tabulating saving, deleting and coping line text. Users do disk top publishing using it.
   
2. 
   Spreadsheet: - Creating, editing, formatting line mathematical tables in rows and columns. Using arithmetical, algebraically, statistical, logical and graphical text documents. Users are the facilities here.
   
3. 
   Database Management System (DBMS):- It is a collection of record programs. Inserting, deleting, copying, updating and saving the records are the facilities here.
   
4. 
   Image processing: - It is a set of programs, which performs graphical pictures and animations. It has different facilities like enlarging rotating, coloring, zooming and many more.
   
5. 
   Engineering Designing Software: - CAL, CAI, CAD, etc. Computer Aided Designing (CAD) is a set o programs, which performs engineering calculations, picture designs, simulations and others.
   
6. 
   Accounting software: - It helps to solve the problems of the accountant. It is use to account keeping properly having many facilities. Accounting package, Repackage and Tally are the examples of the accounting software.
   
7. 
   Statistical software: - It is a collection of programs which performs the statistical activities. It is a kind of powerful statistical tool. SPSS and microstate are the good examples.
   
8. 
   Any other tailor made software: - Locally made any type of software for any type of local institutes.
   

3. 
   Human ware:-
   

1. 
   Data Entry Operator - Non officer
   
2. 
   Data Coder - Non officer
   
3. 
   Data Supervisor - Non officer
   
4. 
   Data Administrator - Officer
   
5. 
   Programmer - Officer
   
6. 
   System Analyst - Officer
   
7. 
   System Designer - Officer
   
8. 
   Computer System Engineer - Officer
   
9. 
   Hardware Engineer - Officer
   
10. 
    Maintenance Engineer - Officer
    
11. 
    Networking Engineer - Officer
    
12. 
    Computer Operator - Non officer
    
13. 
    Computer Instructor - Officer
    
14. 
    Computer Consultants - Officer
    

2. 
   Operating System(OS):
   

1. 
   Introduction OS
   

2. 
   What does a driver do?
   

3. 
   Functions Of The OS
   

1. 
   Job Management– To keep processing jobs in sequence, determining main memory, secondary storage capability and their timing.
   
2. 
   Batch Processing -Any big jobs are classified and grouped in some order, Batch wise they can be processed. For example number wise or alphabetical wise or VDC wise or district wise, etc.
   
3. 
   Data Management – Data can be edited, updated and saved in any storage device. It can be retrieved and stored at any time any data.
   
4. 
   Virtual Storage – Some OS have a feature called virtual storage. Such OS can increase the capacity of the main memory without increasing its size, during processing time, when it is necessary.
   
5. 
   I/O Management – For the smooth input data flow to the CPU and output data flow from the CPU, it can manage. In the big computer system also OS can handle very carefully and accurately. It can stop to handle the data to the unauthorized persons, so it can save data from the less.
   

4. 
   Classification of the OS:
   

1. 
   Multi user: - Any OS, at the same time if more than user can use the OS that is called multi user OS. Some OS permits hundreds or thousands o your to use concurrently. The OS called MVS for the main frame and UNIX for the minicomputer are the multi user OS.
   
2. 
   Multi processing: - Multi processing OS permits many users to use different programs at the same time. MVS and UNIX are two examples used as multi processing OS. Multi processing OS is more complicated than single process systems. Multi processing also refers to the utilizing of multiple CPU in a single computer system called parallel processing.
   
3. 
   Multi tasking:- Multi tasking permits more than one program to run currently. In multi tasking, only one CPU is involved, but it switches from one program to another so that it gives the appearance. Executing all the programs concurrently. There are two types of multi tasking
   
   1. 
      Preemptive - CPU time slices to each program.
      
   2. 
      Co-operative - Each program controls CPU as needed.
      

4. 
   Multi threading:- Multi threading allows different parts of a single program to run currently. If is a ability of an operating system to execute different parts of a program called threads simultaneously, without interfering with each other.
   
5. 
   Real time:- Real time system is an interactive processing system with severe time limitation. Several stations (PC's) can operate a database at the same time. The central input file are updated each time and inquires are answered correctly. Hotel reservation, Air lines ticket reservation and Car rental are the examples of real time system. But DOS and UNIX is not the examples real time system.
   

3. 
   Programming Languages:
   
   1. 
      Introduction
      

2. 
   Machine Language: The language which is written as strings of binary 1s and 0s.It understood by the computer without using a translator. This is basically based at binary system like (On/OF), (Yes/No), (True/False), (Right/ wrong) and (1,0) etc. About 50/60 years back, the computers like ENIAC had used the language only by many switches ON/OFF. There were about 6000 switches for a single program. For the next program the switches had to reset. A process that might take weeks. Thus the programming were like 11110101, 11010011 00011010 etc. This was very tedious such language is called machine language.
   

3. 
   Assembly Language: The language that using alphanumeric mnemonic codes instead of numeric codes for the instructions in the instruction set e.g using ADD instead of 1110(binary) or 14(decimal) for instruction to add. To reduce programming complexity and provide some standardization, assembly languages were developed in 1950. It is known as assembly or symbolic language use abbreviation or mnemonic code like. PACK 210(8, 13), O2B (4, 7) When we provide such assembly language command to the compute, it converts into machine language then it performs the job.
   

4. 
   High-Level Language:
   

1. 
   Types of High-Level Language:
   

a) Procedural – oriented - 3^rd generation computer language

b) Problem- oriented - 4^th generation computer language

c) Nature - 5^th generation computer language

1. 
   Program statements are very similarly to English language
   
2. 
   Very easy to write program.
   
3. 
   Less time consuming to write program.
   
4. 
   Easier to understand and edit.
   
5. 
   The programming languages are machine independents.
   

1. 
   Program takes long time to execute.
   
2. 
   The programming language does not look active.
   

1. 
   Problem oriented language:- The fourth generation languages are called problem oriented language. They are high level language, which are used designed to solve specific problems like word processing, spreadsheet, database management system package program, etc.
   

1. 
   Personal computer application software
   
2. 
   Query language and report generator
   
3. 
   Design support systems and financial planning language
   
4. 
   Application generators.
   

It means word processor, spreadsheet, DBMS, graphics, integrated packages, PowerPoint and other tailor-made

2. 
   Query language and report generator:
   

Decision support system (DSS) is made for managers or chief Execution officers to take decisions. Financial planning languages are also a kind of decision support system, that are employed or mathematical statistical and forecasting procedures.

Example: - Macro Stat, SPSS, Accounting packages, Metaphor, STRATAGEM, etc.

3. 
   application generators:
   

There are other examples of application generators as: FOCUS, FUSION, SAS, SYSTEM, LINE II, RADID/3000 etc.