Configuring A Computer - 1.14 - 1.17

1.14  SMPS

          i)switched mode power supply.

         ii)to supply power to computer and its parts.

         iii)Converts Alternate current(AC) into Direct Current(DC)

 1.15 POWER  CONSUMPTION OF PC

            The power consumption  of  pc  is around 180 watts excluding monitor.

Components	Power Consumption
Monitor	80-100 watts
Hard Disk Drive	80-100 watts
CPU	30 watts
CD-ROM	30 watts
Motherboard	20 watts
Video Graphics card	20 watts
RAM	10 watts
PCI card	5-10 watts
Floppy Drive	5 watts

 1.16 ADVANCED FEATURES

1.16.1 Cache memory :

            i) A small fast memory, which is between the CPU  and the main memory.

            ii)CPU-Resident cache is called as LEVEL1 cache or primary cache.(256-512KB memory)

            iii)Motherboard-Resident cache is called as Level 2 cache.(512-1024KB memory)

           

1.16.2 ADVANCED I-O  INTERFACES

           

1.      USB(Universal serial Bus) : i)Plug and Play devices can be inserted without restarting the computer.

                                         ii)Allows multiple devices-up to 127- to run simultaneously on a computer

2.      I-O PORT : i)Non USB devices

                       ii)can  be connected through serial or parallel port.

3.      PCI interface : i)Peripheral component interconnect  interface is used for all kinds of expansion cards.

                        ii)All sorts of PCI expansion cards are available, including modems,  network cards, sound cards, and video cards.

4.      AGP port : Accelerated Graphic port  interface is used only for video cards.

5.      MIDI Port(Musical instruments Digital Interface) : To connect musical instruments to the system.

6.      Game port : To connect gaming devices to the system.

1.17 CONFIGURING SPECIFICATION OF A PC:

           

1.       Cost:             i)Selecting the components according to budget.

2.      Intended use: i)Selecting the components according to the purpose.

                        ii)Purposes can be office applications , internet surfing, gaming, audio or video editing, music composition etc…

3.      Lifespan:         i)Selecting the current components for the longer duration.

4.      Reputation:    i)Selecting the components according to reviews, newsgroups, and message boards.

5.      Operating system: i)Most of the present computers are with the OS WINDOWS.

                             ii)System components should support, when the purchase is a non Microsoft windows OS.

6.      Compatibility: Reviews can be gathered from newsgroups and message boards about the selected components.

Plug and Play Devices

i.     Plug and play USB devices: i)Devices like keyboards, modems, external hard disk, external CD drive, pen drive, scanners, printers and video devices can be attached easily.

                                       ii)Can be attached through USB ports without switching off or restarting the system.

ii.      Plug sand play cards: i)These cards can be inserted or removed while the system is on preserving data integrity.

                                         ii)The cards such as fax card. Modem card, sound card and AGP card can be  fit easily which are plug and play in nature.

iii.    Expanding the main memory: Main memory can be expanded by adding memory modules.

iv.    Adding HDD, FDD and CDROM drive :These drives can be added to computer through IDE connecters

v.      PC card:  i)Personal computer memory card industry  association Or PCMCIA card or PC card is a small device.

                ii)Designed specifically for notebook and laptop computers but available for desktops also.

              iii)PC cards are used to add memory and plug and play in nature.

          vi) UPS : i)Uninterruptible Power Supply. Can be used during power outage.

                          ii)Types are, Offline UPS(Standby Power Systems) and Online UPS systems

Configuring A Computer - 1.8 - 1.13

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1.8 PRINTERS

                  An output device that produces text and graphics on a physical medium.

1.      Quality type : Letter quality or draft quality.

2.      Speed : Characters  per second (CPS) or pages per minute (PPM),

3.     Impact or Non-Impact :Impact printer is dot-matrix printer(striking ink ribbon).

Non-impact printers are ink-jet printers and laser printers(non striking mechanism).

4.      Graphics : Some printers can print only  text. Other printers can print both text and graphics.

5.      Fonts : Some  printers, like dot matrix printers, are limited to one or few fonts.

Laser  and ink-jet printers are capable of printing variety of fonts

1.8.1 specifications of some   printers :

PRINTER	PRINTING SPEED	BUFFER SIZE
DOT MATRIX	30-300CPS	1K-64K
INK-JET	1-12PPM	1MB-4MB
LASER	4-24PPM	4MB-32MB

Line printer : Contains a chain of characters or pins that  print an entire line at one time.

            Thermal printer : i)pushing heated  pins against heat-sensitive paper.

                                         ii)Widely used in  calculators and fax machines.

1.9 KEYBOARD

          i)Key boards are designed to input text and characters.

          ii)An arrangement of rectangular buttons.

          iii)Characters printed on the keys.

          iv)Types of keys are alphabet,numerical,special and functional.

          v)Multimedia and internet keyboards are available.

1.10 MOUSE

            Controls the movement of cursor or pointer on a display screen.

1.      Mechanical : i)Has a rubber or metal ball on its underside that can roll in all directions. Ii)Mechanical sensors within the mouse detect the directions and move the cursor.

2.      Opto-mechanical: Uses optical sensors to detect  motion of the ball.

3.      Optical: i)Uses a laser to detect the mousers movement  

ii)They respond more quickly.

Mouse can be connected to the compute in one of the following ways :

1.      Serial mouse: They are connected directly to an RS-232C serial port or a PS/2 port.

2.      PS/2 mouse:  They are connected to a PS/2 port.

3.      USB mouse: They are connected through USB port.

4.      Cordless mouse: i) No physical connection.

ii)Instead they rely on infrared or radio waves to communicate with the computer.

1.11 MONITOR OR VIDEO DISPLAY UNIT (VDU)

            Monitors provide a visual display of data.

1.      Monochrome: i)Display two colors. One for the back ground and one for the foreground. ii)Colors can be black and white or Green and black.

2.      Colors: i) Display 1 million colors

Characteristics/Features of a monitor

1.       Refresh data: i)How many times per second the screen is refreshed.

ii) To avoid flickering, the refresh rate should be at least 72 Hz.

2.      Interlaced or non interlaced: Resolution Rate

3.      Convergence: The clarity and sharpness

1.12     RANDOM ACCESS MEMORY

             i)To store the data while using.

           ii)Volatile memory.

           iii)Constant current is required to retain the information.

1.12.1  Types of RAM

1. Static RAM:     i)Has multiple transistors for each memory cell.

                            ii)Need not be refreshed.

            2. Dynamic RAM: Need to be refreshed.

            3.  SDRAM:          i)Synchronous Dynamic Random Access memory.

        ii)Synchronized to the system clock.

        iii)Has the ready-data  when the CPU requests it.

        iv)Increases the efficiency by reducing CPU waiting time.

            4.DDR-RAM:         i)Double Data Rate SDRAM.

     ii)Data transfer rate is double

1.13 SECONDAAARY OR AUXILIARY STORAGE DEVICES:

1.13.1  Floppy disk drive (FDD): i)To record the data.

                                                 ii)Sizes are 8’’, 5.25”,   and 3.5”

                                                 iii)Can store approximately 1 million characters.

1.13.2 Compact Disk : i)An  optical disc  used  to store  digital data.

                                  ii)Types are CD-R and CD-RW.

                                  iii)Can store approximately 700 MB of data

DVD (digital versatile disc or digital video disc :

              Can store approximately 4.7 GB of  data

A Blu -Ray Disc(BD)

               i)A single layer blu-ray Disc can store 25 gigabytes(GB).

               ii) A dual layer blu-ray Disc can store 50 GB.

 1.13.3 Hard Disk Drive (HDD) :

             i)A maximum storage 20 GB – 250 GB.

             ii) Rotational speed is 7200 rpm 

             iii)Types are,.

1.      Small Computer System Interface(SCSI) HDD : For high end users or servers.

2.      Integrated Disk Electronics (IDE)HDD :  Standard in today’s computer.

3.      SERIAL ATA (SATA) :  i)Have large capacity. ii)Have fast transfer rates.

4.      EXTERNAL HDD : Backup disk.