Secondary storage

Secondary Storage

FILE COMPRESSION

File compression is a system that lets Web users reduced the overall number of bits and bytes in a file so that it can be transmitted at a faster speed on a limited broadband. .Programs such as WinZip or WinRar can be used to decompress the file back to its original size. The decompressed file is usually identical to the original file, before it was compressed.

HEAD CRASH

A head crash is the hard-disk malfunction that occurs when the read-write head of a hard disk drive, which normally hovers a few microinches from its rotating platter, gets in contact with it, which will result in permanent and usually fatal damage to the magnetic media on the platter surface. It can also happen when dust or debris accumulates on the surface of the platter.

INTERNET HARD DRIVE

Internet hard drives enable the users to backup their files on the Internet through many backup servies available.Backing up files on the Internet may take a long time, as it depends on the speed of the internet. Likewise, uploading your file back on the computer may also take a long time. However, what internet hard drive offers is the freedom to retrieve any document you need from anywhere in the world.

OPTICAL DISK DRIVE

The optical disc drive (ODD) is a disk drive which uses low-powered laser light or electromagnetic waves near the light spectrum to read or write data to or from optical discks. Optical disc drivs are circular, flat, glass or plast disk in which data can be stored in the form of light and dark pits.  It has mostly replaced magnetic tape drives and floppy disk drives because of the low cost of optical media and the near-ubiquity of optical drives in computers and consumer entertainment hardware.


SOLID-STATE STORAGE

A solid-state storage is a type of nonvolatile, removable data storage device which uses solid-state memory to keep persistent data. It is distinguished from traditional hard disk drives, which are electromechanical devices containing spinning disks and movable read/write heads since solid-state storage does not contains any mechanical parts.

Input and output

Ergonomic keyboard

Its a keyboard that is design to minimize the muscle strain and solve the problems related to wrist ulnar deviation Mostly is at hand deformity, seen in chronic rheumatoid arthritis and lupus erythematosus, in which the swelling of the metacarpophalangeal joints causes the fingers to become displaced to the ulnar side.






Ink-jet printer

Ink-jet printer is a highly equipt printer that have more better quality of image that is printed.Have the ability to produce precise and sharp image quality and they're great for printing documents and spreadsheets. Inkjet Printers with capabilities that make them ideal for either personal or professional use. Enhancements like network connectivity options, elevated dpi, integrated memory and memory card slots among others have made Inkjets Printers extremely relevant in the discussion of today's innovative printers. For instance like canon,epson,hp and etc..

Laser printer.

The type of printer that utilize laser beams to produce image on a drum.It is the high quality of their print and their relatively low running costs.Output quality has improved, with 600 dpi (resouluton of image produce by printers) resolution becoming more standard, and build has become smaller, making them more suited to home use.







Magnetic-ink character recognition(MICR)

It is a common machine language specification for the paper-based payment transfer system.Well it is a character recognition technology adopted mainly by the banking industry to facilitate the processing of cheques. In addition to their unique fonts, MICR characters are printed with a magnetic ink or toner, usually containing iron oxide.







Optical-character recognition (OCR)

The electronic identification and digital encoding of printed or handwritten characters by means of an optical scanner and specialized software.It will do the scanning and comparison technique intended to identify printed text or numerical data. It avoids the need to retype already printed material for data entry

Optical-mark recognition.

It is basicly a type of machine that is specialized more in optical character recognition.It refers to the branch of computer science that involves reading a simple text from paper and translating the images into a form that the computer can manipulate it.This requires the image to have high contrast and an easily-recognizable or irrelevant shape. OMR technology scans a printed form and reads predefined positions and records where marks are made on the form. This technology is useful for applications in which large numbers of hand-filled forms need to be processed quickly and with great accuracy, such as surveys, reply cards, questionnaires and ballots.

 

The system unit

FLASH MEMORY

Its a type of erasible electrically programmeble read only-memory (EEPROM).A common use of flash memory is to store the BIOS settings in a computer's ROM. When the BIOS needs to be changed, the flash memory can be written in blocks, rather than bytes, making it easy to update. Most modems use flash memory for the same reason.Though flash memory was orginally used inside computers, it has invaded many other areas outside the box. Flash memory cards used for digital cameras, cellular phones, networking hardware, and PC cards. Though the memory's read/write speed is not lightning fast, it is nice to be able to tote around a little card rather than a cumbersome hard drive.

GRAPHIC CARDS

A graphics card or video card is a component of a computer which is designed to convert a logical representation of an image stored in memory to a signal that can be used as input for a display medium, most often a monitor utilising a variety of display standard.









SOUND CARDS

The sound card is a component inside the computer that provides audio input and outputcapabilities. Most sound cards have at least one analog line input and one stereo line output connection. The connectors are typically 3.5 mm minijacks, which are the size most headphones use. Some sound cards also support digital audio input and output, either through a standard TRS (tip-ring-sleeve) connection or via an optical audio port, such as Toslink connector.





NETWORK INTERFACE CARD ( NIC)

Short for Network Interface Card, a NIC is also commonly referred to as a network adapter and is an expansion card that enables a computer to connect to a network such as a home network or the Internet using an Ethernet cable with a RJ-45 connector. To the right is a graphic example of an SMC EZ Card 10/100 PCI network card, a network card commonly found in most desktop computers today that do not already have an integrated network on their motherboard



PLUG & PLAY

Plug and Play, sometimes, abbreviated PnP, is a catchy phrase used to describe devices that work with a computer system as soon as they are connected. The user does not have to manually install drivers for the device or even tell the computer that a new device has been added. Instead the computer automatically recognizes the device, loads new drivers for the hardware if needed, and begins to work with the newly connected device.





BUS LINE

While the wheels on the bus may go "round and round," data on a computer's bus goes up and down. Each bus inside a computer consists of set of wires that allow data to be passed back and forth. Most computers have several buses that transmit data to different parts of the machine. Each bus has a certain size, measured in bits (such as 32-bit or 64-bit), that determines how much data can travel across the bus at one time. Buses also have a certain speed, measured in megahertz, which determines how fast the data can travel.The computer's primary bus is called the frontside bus and connects the CPU to the rest of the components on the motherboard. Expansion buses, such as PCI and AGP, allow data to move to and from expansion cards, including video cards and other I/O devices. While there are several buses inside a computer, the speed of the frontside bus is the most important, as it determines how fast data can move in and out of the processor


HDMI

(High-Definition Multimedia Interface) A digital interface for both audio and video signals designed as a small-socket, single-cable solution for home theater and consumer electronics equipment. Introduced in 2002, HDMI is electrically identical to DVI, which is video only, and an HDMI source can detect a DVI device on the other end and switch to the DVI protocol. In the photo below, the 19-pin HDMI plug (left) is much smaller than the 19-pin DVI video-only plug, yet HDMI also supports up to eight channels of 24-bit uncompressed audio at 192kHz.






CACHE MEMORY

The cache is a small amount of high-speed memory, usually with a memory cycle time comparable to the time required by the CPU to fetch one instruction. The cache is usually filled from main memory when instructions or data are fetched into the CPU. Often the main memory will supply a wider data word to the cache than the CPU requires, to fill the cache more rapidly. The amount of information which is replaces at one time in the cache is called the line size for the cache. This is normally the width of the data bus between the cache memory and the main memory. A wide line size for the cache means that several instruction or data words are loaded into the cache at one time, providing a kind of prefetching for instructions or data. Since the cache is small, the effectiveness of the cache relies on the following properties of most programs: