PRACTICAL NO: 1 OBJECTIVE: Identify key board, mouse, CPU, disk drives, disks, monitor and printer.
IDENTIFY KEY BOARD, MOUSE, CPU, DISK DRIVES, DISKS, MONITOR AND PRINTER: KEY BOARD: In computing, a keyboard is typewriter keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches. A keyboard typically has characters engraved or printed on the keys and each press of a key typically corresponds to a single written symbol. However, to produce some symbols requires pressing and holding several keys simultaneously or in sequence. While most keyboard keys produce letters, numbers or signs (characters), other keys or simultaneous key presses can produce actions or computer commands. In normal usage, the keyboard is used to type text and numbers into a word processor, text editor or other program. Keyboards are also used for computer gaming, either with regular keyboards or by using keyboards with special gaming features, which can expedite frequently used keystroke combinations. A keyboard is also used to give commands to the operating system of a computer, such as Windows' Control-AltDelete combination, which brings up a task window or shuts down the machine.
MOUSE: A device that controls the movement of the cursor or pointer on a display screen. A mouse is a small object you can roll along a hard, flat surface. Its name is derived from its shape, which looks a bit like a mouse, its connecting wire that one can imagine to be the mouse's tail, and the fact that one must make it scurry along a surface. As you move the mouse, the pointer on the display screen moves in the same direction. Mice contain at least one button and sometimes as many as three, which have different functions depending on what program is running. Some newer mice also include a scroll wheel for scrolling through long documents. In particular, the mouse is important for graphical user interfaces because you can simply point to options and objects and click a mouse button. Such applications are often called point-and-click programs. The mouse is also useful for graphics programs that allow you to draw pictures by using the mouse like a pen, pencil, or paintbrush. There are three basic types of mice: 1. Mechanical: Has a rubber or metal ball on its underside that can roll in all directions. Mechanical sensors within the mouse detect the direction the ball is rolling and move the screen pointer accordingly. 2. Optomechanical: Same as a mechanical mouse, but uses optical sensors to detect motion of the ball. 3. Optical: Uses a laser to detect the mouse's movement. You must move the mouse along a special mat with a grid so that the optical mechanism has a frame of reference. Optical mice have no mechanical moving parts. They respond more quickly and precisely than mechanical and optomechanical mice, but they are also more expensive.
CPU: Pronounced as separate letters it is the abbreviation for central processing unit (CPU). The CPU is the brains of the computer. Sometimes referred to simply as the central processor, but more commonly called processor, the CPU is where most calculations take place. In terms of computing power, the CPU is the most important element of a computer system. The CPU market is dominated by Intel, AMD, and IBM. These manufacturers supply the computer makers such as Dell, HP, and Apple. On large machines, CPUs require one or more printed circuit boards. On personal computers and small workstations, the CPU is housed in a single chip called a microprocessor. Modern CPUs are small and square and contain multiple metallic connectors or pins on the underside. The CPU is inserted directly into a CPU socket, pin side down, on the motherboard. Modern CPUs also have an attached heat sink and small fan that go directly on top of the CPU to help dissipate heat. Two typical components of a CPU are the following: The arithmetic logic unit (ALU), which performs arithmetic and logical operations. The control unit (CU), which extracts instructions from memory and decodes and executes them, calling on the ALU when necessary.
DISK DRIVE: A disk drive is a device that reads and/or writes data to a disk. The most common type of disk drive is a hard drive (or "hard disk drive"), but several other types of disk drives exist as well. Some examples include removable devices, floppy, and optical drives, which read optical media, such as CDs and DVDs. While there are multiple types of disk drives, they all work in a similar fashion. Each drive operates by spinning a disk and reading data from it using a small component called a drive head. Hard drives and removable disk drives use a magnetic head, while optical drives use a laser. CD and DVD burners include a high-powered laser that can imprint data onto discs. Since hard drives are now available in such large capacities, there is little need for removable disk drives. Instead of expanding a system's storage capacity with removable media, most people now use external hard drives instead. While CD and DVD drives are still common, they have become less used since software, movies, and music can now often be downloaded from the Internet. Therefore, internal hard drives (housed within the computer) and external hard drives (housed in a separate box that connects to the computer) are the most common types of disk drives used today.
MONITOR: The term "monitor" is often used synonymously with "computer screen" or "display." The monitor displays the computer's user interface and open programs, allowing the user to interact with the computer, typically using the keyboard and mouse. Older computer monitors were built using cathode ray tubes (CRTs), which made them rather heavy and caused them to take up a lot of desk space. Most modern monitors are built using LCD technology and are commonly referred to as flat screen displays. These thin monitors take up much less space than the older CRT displays. This means people with LCD monitors have more desk space to clutter up with stacks of papers, pens, and other objects.
PRINTER: In computers, a printer is a device that accepts text and graphic output from a computer and transfers the information to paper, usually to standard size sheets of paper. Printers vary in size, speed, sophistication, and cost. In general, more expensive printers are used for higher-resolution color printing. Personal computer printers can be distinguished as impact or non-impact printers. Early impact printers worked something like an automatic typewriter, with a key striking an inked impression on paper for each printed character . The dot-matrix printer was a popular low-cost personal computer printer. It's an impact printer that strikes the paper a line at a time. The best-known non-impact printers are the inkjet printer, of which several makes of low-cost color printers are an example, and the laser printer . The inkjet sprays ink from an ink cartridge at very close range to the paper as it rolls by. The laser printer uses a laser beam reflected from a mirror to attract ink (called toner) to selected paper areas as a sheet rolls over a drum. The four printer qualities of most interest to most users are:
Color: Color quality of the printer. Resolution: Printer resolution (the sharpness of text and images on paper) is usually measured in dots per inch (dpi ). Speed: Speed of the printer with which it takes out the prints. Memory: Most printers come with a small amount of memory (for example, one megabyte ) that can be expanded by the user.
PRACTICAL NO: 2 OBJECTIVE: Practice for booting up of a computer system with DOS system disk and power off system at DOS prompt.
BOOTING UP COMPUTER WITH DOS DISK: Booting up computer system with DOS system disk means that you are booting up the computer system through DOS mode. For this purpose you should first insert the bootable disk which has the capability of booting up the computer and for this the DOS system should already be installed in the computer system. When you insert the bootable disk the system starts booting and a message in DOS mode appears as shown below:
POWER OFF SYSTEM AT DOS PROMPT: In order to power off the system at DOS prompt you should just simply write exit while being in the environment of DOS mode and after that the DOS system turns off just as when you turn off your system by plugging off the main switch of the computer system. Image of exiting from DOS mode is shown in figure below:
PRACTICAL NO: 3 OBJECTIVE: Practice for CLS, VER, VOL, DATE and TIME commands.
PRACTICE FOR CLS, VER, VOL, DATE AND TIME COMMANDS: CLS: Syntax: cls Purpose: This is the clear the screen command. All existing text on the screen will be cleared and the prompt placed at the top left hand corner of the screen ready for the next command. Example: C:\> cls
Syntax: VER Purpose: VER displays the DOS version number for the version of DOS currently active. Example To display the currently operating version of DOS, enter C:\> ver
The program will display MS-DOS Version (version number) VOL (VOLUME) Syntax: vol [Drive:] Purpose: Displays the disk volume label and serial number, if they exist. A serial number is displayed for a disk formatted with MS-DOS version 4.0 or later. Example: To display the currently operating version of DOS, enter C:\> vol The program will display Volume in C drive has no label. Volume Serial Number is 3R62-BD15
DATE Syntax: Displays or sets the date. DATE [/T | date] Parameters: Type DATE without parameters to display the current date setting and a prompt for a new one. Press ENTER to keep the same date. If Command Extensions are enabled the DATE command supports the /T switch which tells the command to just output the current date, without prompting for a new date.
C:\Date TIME Syntax: TIME TIME hh:m