Discuss about Computers for Individual Users

Semester:-1

Unit:-1

Discuss about Computers for Individual Users. ?
Ans:-
          Most Computers are meant to be used by only one person at a time. Such computers are often shared by several people. But only one user can work with the machine at any given moment. The five primary type of computers in this category are
Computer for Individual Users

• Desktop computers
• Workstation
• Laptops
• Network computers
• Hand held devices

Desktop PCs:
                       A desktop PC is the most popular model of PCs. The system unit of the desktop PC can be placed flat on a desk or table. It is widely used in homes and offices.

Work stations:
                         A workstation is a specialized , single user computer that typically has more powerful than a standard desktop PC. These machines are popular among scientist , engineers, and animators who need a system with greater than average speed and the power to perform sophisticated tasks. Workstations often have large, high resolution monitors and accelerated graphics handling capabilities, making them suitable for advanced architectural or engineering design, modeling, animation and video editing.
Laptops:
               Laptops are very handy and can easily carried from one place to another. They may also be placed on the user's lap . Hance , laptops are very useful, especially when going on long journeys.

Laptops operate on a special battery and do not always have to be plugged in linke desktop computers. The memory and storage capacity of a laptop is almost equivalent to that of a desktop computer. As with desktop computers, laptops also have a screen, keyboard, and a trackpad or trackball , which servers as the mouse. However   a drawback is that laptops are generally more expensive than desktop computers. These computers are very popular among business travelers.

Network Computers:

                                      A Computer with minimal Memory, disk storage and processer power disigned to connect to a network, especially the Internet. The idea behind network Computers is that many user who are connected to a network don't need all the computer power they get from a typical personal computer. Instead , they can rely on the power of the network servers.

Hand Held Computer:

                 Handheld personal Computers are computing devices small enough to fit in your hand . Some examples of handheld computers are:

• Personal Digital Assistant (PDA)
• Cellular phones
• H/PC pro Device.

               A popular type of handheld computers is the personal Digital assistant(PDA). A PDA is no larger then a small appointment book and is normally used for special applications, such as taking notes, displaying telephone numbers and addresses, and keeping track of dates or agendas.

                Cellular phone are web enabled telephones that have features of both analogue and digital devices. Such phones are also known as smart phones. Because, in addition to basic phone capabilities, they also support access the internet and send e mails and faxes.

                H/PC pro Devices is the new developments in handheld technology. The size and features of the H/PC pro Devices is more than PDAs but less than that of typical notbook PCs. The H/PC pro Devices includes a full sized keyboard, RAM with very low storage capacity, and a slow speed processor. These Devices fo not have a secondary storage disk.

Explain different Computer Hardware parts

Semester:-1

Unit:-5

Explain different Computer Hardware parts. ?
Ans:-
          The physical parts of the computer that we can see and touch are known as computer hardware. Computer software is just like the human soul, which can not be touched and computer hardware is like body which we can see and touch.
Motherboard : 

• This is the part of the computer where everything is placed or connected to. It holds the slot and ports where the other parts will be attached.
• When upgrading or buying a motherboard make sure it contain the most recent slots and ports to ensure that you will not limited in the kind of parts you install into it.
• Example there are two kinds of ports for a CD/DVD drive and hard drive. It can be the earlier IDE or a SATA port. Some motherboards can carry both IDE and SATA during the period where SATA is still new.

Processor :

• This is the "brain" of the computer because it does necessary computations and logical operations to run a program.
• At the moment of writing the most known processors brands are Intel and AMD . Intel are best for office and desktop publishing work while AMD is best for gaming.

RAM :

•            This means Random Access Memory and is responsible for becoming temporary storage for use by actively running programs and processes of a computer.
• Generally the higher the RAM the more programs you can run at the same time but the processor would play a big part two in determining if these programs will run smoothly.
• RAM comes in size of 512 kb , 1GB, 2GB, 4GB and 8GB. Usually there are only two slots available so if you hear that they are selling a computer with 3GB of RAM then it is most likely composed on a 2GB and 1GB sticks of RAM.
• Typically a laptop RAM would come also in smaller size.

Hard Disk Drive :

• The programs, files and pictures are stored in a hard disk drive.
• It comes in either with a SATA port or IDE port, the latter being the older model.
• SATA allows much higher capacity of data that can be transferred with also a much slimmer cables to be used.
• Desktop hard disk drives are about 3.5 inches while laptop hard disk drives are 2.5 inches.
• It comes in storage sizes of 80GB, 120GB, 160GB, 240GB, 320GB, 640GB, 1TB, 2TB, 3TB etc .
• Please note that if you get a 649GB it doesn't equally mean to be 640GB exactly. It may fall off a few kilobytes because the conversion is not exact. 1024 bytes = 1 kilobytes(KB), 1024 KB = 1 Megabytes (MB), 1024 MB = 1 Terabytes (TB), 1024 TB = 1 Gigabytes(GB).

CD / DVD Drive :

• This is where you put your CDs and DVDs do you can view their content inside the computer.
• If you get one with a write feature it can also be used to back-up or save data from your computer into a CD and DVD. The CD and DVD you must though must also be writable.
• Like the hard disk drive it can also be either for a SATA or IDE port , the latter being the older model.
• A desktop can carry as many as 3 CD-DVD drives at the same time depending on the number of bays which can be carried by the case used however for a laptop there is only one CD-DVD drive available, sometimes none at all like with netbooks.

Internal CD/DVD drive

External CD/DVD drive

Video Card :

• They are expansion cards which allows to creates the images to be displayed out to the monitor.
• Motherboards nowadays have their on-board video and this would share memory from the RAM but some more advanced boards would have their dedicated Memory even if it is on-board specially with laptops. 
• You may consider using a video Card instead of an on-board video if you wish to run more power hungry graphics like for computer games and multimedia editing.
• Be careful not just to buy any kind of video Card and always check what your motherboard can handle are there now several lost types for use on video cards. The latest now are PCIs.

Explain in detail Magnetic Disks

Semester:-1

Unit:-4

Explain in detail Magnetic Disks
Ans:-
          A round plate on which data can be encoded. There are two basic types of disks: magnetic disks and optical disks.
            On magnetic disks, data is encoded as microscopic magnetized needles on the disk's surface. You can record and erase data on a magnetic disks any number of times, just as you can with a cassette tape. Magnetic disks come in a number of different froms:
Floppy Disk :
                       A typical 5 1/4 - inch Floppy disk can hold 360K or 1.2MB (megabytes). 3 1/2 - inch floppies normally store 720K, 1.2MB or 1.44MB of data.

Hard disk : 
                    Hard disks can store anywhere from 20MB to more than 200 GB. Hard disks are also from 10 to 100 times faster than Floppy disks.
Removable Cartridge :
                                        Removable Cartridge are hard disks encased in a metal or plastic Cartridge, so you can remove them just like a Floppy disks. Removable Cartridge are very fast , though usually not as fast as fixed hard disks.

Discuss about Various Secondary Storages Devices.

Semester:-1

Unit:-4

Discuss about Various Secondary Storages Devices ?

Ans:-
          When the computer is switched off, anything stored in the RAM is lost. To avoid this situation, magnetic disks are used to store data permanently. The data , on these disks, won't be affected when we turn off our computer.
a) Floppy Disk : 
                            A Floppy Disk is a reusable data storage device that is composed of a disk of thin, flexible ("Floppy" ) magnetic storage medium encased in a square or rectangular plastic shell. Also called a " diskette", the Floppy is a flexible circle of magnetic material similar to magnetic tape , except that both sides are used. The read/write head contact the surface through an opening in the plastic shell or envelope. Floppies rotate at 300 RPM, which is from 10 to 30 times slower than a hard disk. Floppy disks basically come in three sizes, they are 8 inches, 5 1/4 inch , and 3 1/2 inch .

b) Hard Disk :
                        A hard disk, is also a permanent storage , where we can store lot of information. Capacity of a hard disk is measured in megabytes ( MB), Gigabytes (GB) or Terabytes (TB) and they come in various different sizes. Usually every computer now a day comes with hard disk.

The information in hard disk is stored in circular magnetic disks called plates , in the form of program files and data files.
c) CD-ROM ( Compact disk-Read only memory) :
                  CD-ROM is also one of the commonly used secondary storage device. The main advantage of CD-ROM is, they can store large volumes of data I.e., 700 MB to 1.4 GB and also they are cheaper and easy to handle. It is made up small plastic disk, coated with aluminum or silver for magnetization. A layer or transparent plastic is further deposited on the disk . The data is recorded in spiral tracks and the data once recorded cannot be deleted or rewritten , but can be read any number of times .
               In this technology, a high power laser beam is used to record data by burning tiny pits in the surface of the hard plastic disk . To read the data, a low power laser beam is used to scan the disk surface. The data are stored in binary digits . When the laser beam reflect from the smooth surface of the disk it is interpreted as a 1 bit and when the beam enters the tiny pits it is interpreted as a 0 bit .
Advantages : 

• High Storage Capacity
• Easy to use in multimedia applications.
• Handled easily
• Can read / Rewrite using CD-RW's

Disadvantage: 

• CD Writing can be done carefully
• Should be kept free from dust and heat.

d) Magnetic Tape :
                                 Magnetic Tape is the oldest form of secondary storage device. It is one of the popular storage medium for storing large amount of sequential data . It is also used as a backup storage for data stored on on-line storage devices.
The magnetic tape medium is a plastic ribbon usually 1/2 inch or 1/4 inch wide and 50 to 2400 feet long. It is coated with a magnetizable recording material such as iron-oxide or chromium dioxide . Data are recorded on the tape in the form of tiny invisible magnetized and non-magnetize spots on the coated surface of the tape.
Advantages :

• Non-volatile Memory
• Voluminous data can be stored.

Disadvantages :

• Only sequential data processing
• Complex mechanism required.
• After few days the data can be mounted to tape , we need to recall the data to store it into hard disk as and when required .

Fig: Magnetic Tape

Elucidate Data processing in computer.

Semester:-1

Unit:-3

Elucidate Data processing in computer.?

Ans:-

          Before data is processed by a computer. It has to be fed into the computer using a keyboard. Mouse or another input device. The central processing unit ( CPU) analyzes the raw data and processes it into sensible information. The CPU receives instructions from the user and issues prompts accordingly. After the data is processed. It is translated to output formats that are easily understandable by the user.

       The processed data is displayed on the computer for editing, viewing or playing. The computers CPU then receives instructions from the user to save the data securely on the hard drive . Later, the user can choose to modify, copy, move , edit or delete the data. Some of the output values that data is converted into are documents , video files and audio files.

            A computer system is comprised of three main parts : hardware, software and users. All components connected to the computer via cable or wireless access point are hardware. These are primarily the tangible parts that include the CPU , monitor keyboard and mouse. In addition, machines such as printers and scanners are considered part of the computers hardware. Software consists of the computer applications installed in the computer and used to execute functions. Users are the people who provide instructions to the computer.

Explain in detail Data Representation in Computers.

Semester:-1

Unit:-3

Explain in detail Data Representation in Computers. ?

Ans:-
           All data is represented by the state of the computer's electric switches. A switch has only two possible states 'ON'and ' OFF' so it can represent only two numeric values ( IE 0 and 1). To a computer ,when a switch is 'OFF', it represents a 0; when a switch is 'ON', it represents a  1. Because computers worked based on the binary number system. This number system base is 2. It contains digits 0 and 1. The binary digit either 0 or 1 is called BIT. 
Tax codes:-
                      Early programmers realized that they needed a  standard text code that was agreeable to all of them . In such a system,  numbers would represent the  letter of the alphabet, punctuation marks,  and other symbols. This standard code system would enable any programmer to use the same combinations of numbers to represent the same individual pieces of data.  The four most popular text code systems invented are the following :
EBCDIC:- 
                   EBCDIC stands for Extended Binary coded Decimal Interchange code. EBCDIC is an eighth bit code that defineds 256 symbols. It is still used in IBM mainframe and mid-range systems , but it is rarely encountered in personal computers .
ASCII:-
              ASCII stands for the American standard code for information interchange. The ASCII character set is most commonly used in all types computers.  ASCII is an eighth-bit code that specifics characters from values from 0 to 127. 
Extended ASCII:-
                                 Extended ASCII  is an eighth bit code that specifics the characters for values from  128 to 255. The first 40 symbols represent special punctuation.  The remaining symbols are graphic symbols. 
Unicode :-
                    The Unicode Worldwide Character standard  provides up to  four bytes to represent each letter , number or symbol. With four  bytes , enough Unicode codes can be created to represent more than 4 billion different characters or symbols.  This total is enough for every unique character and symbol in the world . One major advantage that Unicode has over other text code systems is it's compatibility with ASCII  codes.  The first 256 codes in Unicode are identical to the 256 codes used by the ASCII and Extended ASCII systems. 

Discuss about the keyboard.

Semester :-1

Unit:-2

Discuss about the keyboard.?
Ans:-   

           An input device Is used to feed data and instructions into the computer. The keyboard is the main input device for computers.
               Using a keyboard, the user can type a document,use keystroke shortcut,access menus,play games and perform numerous other tasks.most keyboards have between 80 and 110 keys, which include the following: 
Typing keys :-
                          These include the letters of the alphabet.The layout of a keyboard is known as QWERTY for its first six letters. The QWERTY pattern has been a standard right from the time computer keyboards were introduced.
Numeric keys:-
                             These include a set of 17 keys, arranged in the same configuration found on calculators to speed up data entry of numbers.when the num lock key is set to on, the user can type number dot or input the symbols/,*,-, and+. When the num lock key is set to off , the numeric keys can be used to move the cursor on the screen.
Function keys :-
                               These are used by applications and operating systems to input specific commands.they are often placed on the top of the keyboard in a single row . function key can be programmed so that their functionality varies from one program to another.
Control keys:-
                           These are used to handle control of the cursor and the screen. Four arrow keys are arranged in an inverted T-type fashion between the typing and the numeric keys, and are used to move the cursor on the screen in small increments. In addition to the arrow keys, there are other cursor keys ( or navigational keys ), such as :

• Home and End to move the cursor to the beginning and end of the current line , respectively
• Page up and page down to move to the previous and the next pages , respectively
• Insert to enter a character between two existing characters
• Delete to deleted a character at the cursor position

Other common control keys on the keyboard include control ( Ctrl) , Alternate ( Alt), Escape( ESC) , print screen pause , the windows or start key ( Microsoft Windows logo) , and a shortcut key. The shortcut key has a mouse pointer printed on it and is used to access the options available by pressing the right mouse button.the ESC key cancel the selected option, and the pause key suspends a command / process in progress. Finally, the print screen key captures everything on the screen as an image . The image can be pasted into any document