Optical Fiber

An optical fiber cable is a transmission medium in which is made up of glass (silica) and the data's are transferred as optical signals (light signals). LASER or a LED is used for transmitting the optical signal (data) and a photodiode is used for receiving the optical signal.

Data transmission through optical fiber cable will be faster than co-axial cable and twisted pair cable (both uses copper strand as the medium of communication). The optical signal wont travel in a straight line. The rays will reflects on wall of the glass strand. The cable is surrounded by many layers, this will helps to prevent external noise and refraction of signal.

Types of fiber cable

                  There are three basic types of fiber cable:

• Single mode fiber optic cable
• Multi-mode step index optic cable
• Multi-mode gradient index optic cable

Types of fiber optic connectors

• ST

• SC

• FC

• FDDI

• Mini-BNC

• BICONIC

• LC

• SMA

• MT-RJ

SMA connector is used in most of the optical communication, because it is water-resistant and durable compared to the other type of connectors.

Ivy Bridge Processor

Ivy bridge processor is the successor of Sandy Bridge processor from Intel. Ivy bridge processor is expected to be released in September, 2012. It is developed under the "Core" brand. Ivy bridge architecture will be used in Core i3,i5 and i7 processors.

Ivy bridge architecture is designed to work in 22nm whereas Sandy Bridge works in 32nm. So far all the processors worked with planar (2D) transistors whereas Ivy bridge uses tri-gate (3D) transistors. As a result, the speed of processing will be more with less power consumption.

The speed of the processor is from 2.5 to 4.2 GHz (upto 3.9 GHz can be used for workstations and above 4 GHz speed can be used in servers). Ivy Bridge is designed with tertiary cache memory (L3). The size of cache is from 3 MB to 8 MB which will boosts the speed of execution.

Ivy bridge supports USB 3.0. Ivy bridge allows backward compatibility. So that, the motherboard of Sandy bridge processor can be used to Ivy bridge processor.

Features

• Less power consumption
• High Performance
• PCI-E support
• Support HD 4000 graphics
• Support for DDR3 RAM
• Supports USB 3.0

Ivy bridge architecture is used for mobile processors too. Ivy bridge is the predecessor for "Haswell" architecture. 

Drive Interface

Drive interfaces are used to connect the drives (hard drive and optical drive) with motherboard and power supply (SMPS). The drive interface is used for both power supply and data transfer. The three types of drive interfaces are:

• PATA - Parallel Advanced Technology Attachment
• SATA - Serial Advanced Technology Attachment
• SCSI - Small Computer System Interface

Parallel Advanced Technology Attachment (PATA)

            PATA is used to connect the hard drive with the motherboard. The maximum data transfer rate achieved in PATA is 133 Mbps. PATA contains two channels in a single cable. They are called as Master and Slave.

Serial Advanced Technology Attachment (SATA)

         

         SATA is also used to connect hard drive with the motherboard. SATA is used to carry both the power and the data in a single cable. SATA replaced PATA technology. The maximum data transfer rate in SATA is 600Mbps. SATA has only one channel in a single cable.

Small Computer System Interface (SCSI)

           SCSI is a drive interface which is additionally included in thee system. by default, SCSI will not present in a system. It should be added using adapters for using SCSI. It is a buffered, peer-to-peer interface connection). Upto 16 devices can be connected in a single port. The data transfer rate in SCSI is 80 MBps.

Differences between PATA & SATA

• SATA consumes lesser power than PATA.
• SATA has higher data transfer rate than PATA.
• 2 channels can be connected in a single cable in PATA whereas only one channel can be connected in SATA.
• SATA's cable length is longer than PATA and PATA's cable is wider than SATA.
• SATA allows dull duplex communication and it is not possible in PATA.
• PATA is incompatible with many devices, SATA is compatible with all the devices.

USB

Universal Serial Bus. It was developed in the year 1994. Initially USB ports are added to a machine using I/O adapters. Slowly the usage of USB started to increase. Now the USB ports are provided as in-built ports. 

Now all the devices are manufactured with USB ports. Most of the devices are built with USB port instead of parallel and serial ports. Some of the devices that uses USB for connection with system unit are:

• Keyboard
• Mouse
• Webcam
• Speaker
• Joystick
• Printer
• Digital Camera
• Hard disk (external)
• Mobile Phones

USB enables the "Plug and Play" feature. That is, the connected device will be automatically recognized and the device driver will be automatically selected and it will be ready to use. USB uses the technology called "Hot Swapping", in which the devices does not need external power supply for working. Upto 127 devices can be connected to a single port (using hubs). 

The mobile phones uses the USB port for charging.The mobile phones uses the USB port for charging.

Versions

•      1.0 & 1.1 - Data transfer rate is 12 Mbps
•      2.0           - Data transfer rate is 480 Mbps.
•      3.0           - Supports data transfer rate upto 4.8 Gbps.

Types of USB Ports

• USB A-TYPE

• USB B-TYPE

• Micro-USB A

• Micro-USB B

• Micro-USB AB

• USB Mini-b

• USB 3.0 A-TYPE

• USB 3.0 B-TYPE

• USB Micro B

Optical Disc

Optical disk is a storage device. Read & Write operations are done using optical (light) signals. Optical disks  came to use after 'Floppies' which was used as storage device. Optical disks contains many advantages over floppies. Some of the advantages are:

• Portable (easy to transport)
• More storage space
• Reusable

Types
      Optical discs are differentiated based on size and some other factors. Some of the types are:

• CD (Compact Disc)

            It was developed by Sony in the year 1976. The maximum size a CD is 700 MB. This uses Compact Disk File Format (CDFS) filesystem. The various types of CD are: CD-R (CD Recordable), CD-ROM (CD Read Only Memory), CD-RW (CD Rewritable).

          

• DVD (Digital Versatile Disc)

                  It was developed by Philips, Sony, Toshiba and Panasonic in 1995. DVD's have more storage capacity compared to CD's. The storage capacity is from 4.7 GB to 9.4 GB. This uses Universal Digital Format (UDF) format filesystem. The various types of DVD are: DVD-ROM (Read Only Memory), DVD-R (DVD Recordable), DVD-RW (DVD Rewritable).

• Blu-ray

                It was developed in the year 2000 by Sony and Philips. Blu-ray discs has more storage capacity compared to DVD's. This uses Universal Disk Format (UDF) filesystem. The storage capacity is 25 and 50 GB for single and dual layers respectively. 

           Blu-ray can be used upto 200 GB by using multiple dual layers.

• LaserDisc

             It is the grandfather of the optical storage medium. It was developed in the year 1958 by Philips, MCA and Pioneer. This uses analog signals to record the videos. Its diameter is 30cm, which looks like a huge sized DVD. It can be recorded only once. It can be used for playback only.

• Magneto Optical Disc

                  Magneto optical discs looks like floppy discs. But both are different. Floppies use magnetic signals to read and write. But the magneto optical disk uses optical signals to read and write the data. The size of magneto optical disc exists from 650MB to 9.2GB. These disks are available in SCSI (Small Computer System Interface), IDE (Integrated Drive Electronics), USB (Universal Serial BUS).

• FMD (Fluorescent Multilayer Disc)

                 FMD is different from CD and DVD. CD and DVD uses reflective light to store data's, but FMD uses fluorescent light for storing data. CD's and DVD's have the limitations (upto 2 layers) for storing data's. FMD uses 3D optical data storage principle in which the data's can be stored even in 100 layers. The size of FMD's is from 50GB to TB's(terabytes). The FMD will be a transparent disc.

• DMD (Digital Multilayer Disc)

                  DMD's are based on FMD principles. It is developed by D Data Inc. It can store 22 to 32GB binary data. The storage capacity can potentially support upto 100GB. DMD is also a transparent disc.

• UDO (Ultra Density Optical)

                    UDO's are designed to store the data's (videos) in high definition. The size of UDO's are 30 and 60GB. The types of UDO are: WORM (Write Once Read Many), R/W (Rewritable), Compliant WORM.

• PFD (Professional Disc)

                      PFD was introduced in 2003 by Sony. It is a digital recording optical disc for XDCAM and tapeless camcorder. 23GB data can be stored in a single layer PFD and 50GB data can be stored in a dual-layer PFD. PFD supports both standard definition and high definition. Professional Disc for Data (PDD) is a type of PFD, which is used to store data's. It is mostly used by the enterprises for taking backup's.

• VMD (Versatile Multilayer Disc)

                       VMD is a high capacity red laser optical disc. It was developed to compete with Blue-ray. VMD was developed by New Medium Enterprises. The capacity of each layer in VMD is 5GB. The standard size of VMD is 20GB and the maximum size is 30GB. This disc can be used for storing high definition videos.

• HVD (Holographic Versatile Disc)

                     It was developed between 2004 and 2008. HVD was designed to store data's in terabytes (TB). The principle used here is holography, in which red and green rays are combined as a single ray and used for reading and writing. The reading and writing of different type of information are done by using different rays. 100 and 200GB HVD's were introduced in the year 2007.The maximum size of an HVD is 6TB.

• Tapestry Media

                  Tapestry media is similar to holographic versatile disc (HVD). It was developed by InPhase Technologies. Tapestry holographic media is designed to store upto 300GB data. This is used for storing high definition videos and high-end enterprise applications. 

Keyboard

Keyboard is an input device. It is used to give instructions to the system. The keyboard is used to type the letters and it can be used for performing shortcuts while accessing.

Connector types:

• DIN Connector

• PS/2  Connector

• Serial  Connector

• USB

• Wireless

     

Types:

• XT Keyboard

              XT keyboard are the keyboards used with Fullsize AT and Baby AT motherboards. It has 83 keys. XT keyboard contains "Function keys" from F1 to F10. XT keyboard uses DIN connector.

• AT Keyboard

              AT keyboard was introduced with 84 keys. Later it was developed with 101 keys ( as enhanced). AT keyboard also uses the DIN connector for connecting the keyboard with the system unit.

• Standard Keyboard

                   It is the enhanced version of AT keyboard. Standard keyboard contains some additional function keys like Insert, Delete, Home, End, Page Up, Page Down. The standard keyboard is available with both serial connector and with PS/2 connector.

• Multimedia Keyboard

                          Multimedia keyboard is the modern keyboard. It is manufactured with keys such as E-mail, keys for media player, etc,. It is available with PS/2 and USB connector.

• Ergonomic Keyboard

                    Ergonomic keyboard is designed in a different shape which will be more convenient to the user for typing. It is partitioned into two parts which is for easy to use. Ergonomic keyboard is available with PS/2 and USB connectors.