Hard Disk Drive(HDD)

A hard disk drive (HDD), usually referred to as a hard drive, hard disk, or fixed disk drive, is a non-volatile storage device which stores digitally encoded data on quickly rotating platters with magnetic surfaces. Severely speaking, "drive" refers to a device separate from its medium, such as a tape drive and its tape, or a floppy disk drive and its floppy disk. Early HDDs had detachable media; however, an HDD today is classically a sealed unit (apart from for a filtered vent hole to make equal air pressure) with fixed media.

The device that reads and writes data on a hard disk. Hard disk drives (HDDs) for PCs usually have sought times of about 12 milliseconds or less. Many disk drives improve their performance during a technique called caching.

There are more than a few interface standards for passing data between a hard disk and a computer. The most common are IDE and SCSI.

Hard disk drives are sometimes called Winchester drives, Winchester being the name of one of the first well-liked hard disk drive technologies urbanized by IBM in 1973.

Floppy disk

A floppy disk is a data storage medium that is collected of a disk of thin, flexible ("floppy") magnetic storage medium covered in a square or rectangular plastic shell. Floppy disks are read and written by a floppy disk drive or FDD, the initials of which should not be perplexed with "fixed disk drive", which is one more term for a hard disk drive.

Floppies come in three essential sizes:

8-inch: The first floppy disk design, imaginary by IBM in the late 1960s and used in the early 1970s as first a read-only format and then as a read-write format. The typical desktop/laptop computer does not employ the 8-inch floppy disk.

5¼-inch: The ordinary size for PCs made before 1987 and the precursor to the 8-inch floppy disk. This type of floppy is usually capable of storing between 100K and 1.2MB (megabytes) of data. The most ordinary sizes are 360K and 1.2MB.

3½-inch: Floppy is something of a misnomer for these disks, as they are covered in an unbending envelope. In spite of their small size, microfloppies contain a larger storage capacity than their cousins -- from 400K to 1.4MB of data. The most common sizes for PCs are 720K (double-density) and 1.44MB (high-density). Macintoshes hold up disks of 400K, 800K, and 1.2MB.

Blu-ray Disc

Blu-ray, also known as Blu-ray Disc (BD), is the name of a next-generation optical disc format together developed by the Blu-ray Disc Association (BDA), a collection of the world's most important consumer electronics, personal computer and media manufacturers (including Apple, Dell, Hitachi, HP, JVC, LG, Mitsubishi, Panasonic, Pioneer, Philips, Samsung, Sharp, Sony, TDK and Thomson). The format was developed to allow recording, rewriting and playback of high-definition video (HD), as well as storing large amounts of data. The format offers more than five times the storage capacity of conventional DVDs and can grasp up to 25GB on a single-layer disc and 50GB on a dual-layer disc.

While present optical disc technologies such as DVD, DVD±R, DVD±RW, and DVD-RAM rely on a red laser to read and write data, the new format uses a blue-violet laser in its place, hence the name Blu-ray. In spite of the different type of lasers used, Blu-ray products can easily be completed backwards compatible with CDs and DVDs through the use of a BD/DVD/CD compatible optical pickup unit. The advantage of using a blue-violet laser (405nm) is that it has a shorter wavelength than a red laser (650nm), which makes it probable to focus the laser spot with even greater precision. This allows data to be crowded more tightly and stored in less space, so it's possible to fit more data on the disc still though it's the same size as a CD/DVD. This mutually with the change of numerical aperture to 0.85 is what enables Blu-ray Discs to grasp 25GB/50GB.

DVD

DVDr (also known as "Digital Versatile Disc" or "Digital Video Disc") is a popular optical disc storage media format. Its major uses are video and data storage. Most DVDs are of the similar dimensions as compact discs (CDs) but store more than six times as much data.

Variations of the term DVD often explain the way data is stored on the discs: DVD-ROM has data which can merely be read and not written, DVD-R and DVD+R can only record data one time and then function as a DVD-ROM. DVD-RW and DVD+RW can both record and remove data multiple times. The wavelength used by normal DVD lasers is 650 nm, and thus has a red color.

DVD-Video and DVD-Audio discs respectively refer to correctly formatted and structured audio and video content. Other types of DVDs, counting those with video content, may be referred to as DVD-Data discs. After that generation High definition optical formats also use a disc identical in some aspects yet more higher than a DVD, such as Blu-ray Disc, the original DVD is infrequently given the retronym SD DVD (for standard definition

Peripheral Component Interconnect

PCI (Peripheral Component Interconnect) is an industry condition for connecting hardware devices to a computer's central processor. Both Ethernet and Wi-Fi network adapters for desktop and notebook computers usually utilize PCI.

PCI defines the electrical characteristics and signal protocol used for two devices to converse over a computer's central bus. PCI network adapters and other devices be in more than a few different shapes and sizes called "form factors."

Besides traditional Ethernet PCI cards that manufacturers pre-install in desktop computers, ordinary PCI form factors for consumer network devices are:

* Card Bus - also Wi-Fi or Ethernet PC Card (also known as PCMCIA or "credit card") network adapters
* Mini PCI - Wi-Fi network cards fixed inside notebook computers

Internal bus

In computer architecture, a bus is a subsystem so as to transfers data between computer components within a computer or between computers. Unlike a point-to-point connection, a bus can rationally connect several peripherals in excess of the same set of wires. Each bus defines its set of connectors to bodily plug devices, cards or cables jointly.

Early computer buses were literally similar electrical buses with multiple connections, but the term is now used for any physical arrangement that provides the same logical functionality as a equivalent electrical bus. Modern computer buses can use both parallel and bit-serial connections, and can be wired in also a multidrop (electrical parallel) or daisy chain topology, or linked by switched hubs, as in the container of USB.

Computer fan

A computer fan can be some fan inside a computer case used for cooling purposes, and may refer to fans that sketch cooler air into the container from the outside, drive out warm air from inside, or move air across a heat sink to cool a exacting component. The use of fans and/or other hardware to cool a computer is sometimes referred to as lively cooling.

Used to inferior the temperature of the computer; a fan is almost always attached to the CPU, and the computer case will usually have several fans to maintain a constant airflow. Liquid cooling can also be used to cool a computer, while it focuses more on individual parts quite than the overall temperature within the chassis.

Video Display Controller

A video display controller which can display foregrounds as well as backgrounds of display patterns on a screen of a video display unit in a plurality of colors . The video display controller comprises a plurality of color in order registers, in each of which a pair of color code data representative of center and backdrop colors of one display pattern are stored. A memory is provided for storing a plurality of prototype data, a plurality of pattern name data every designating one of the display patterns to be displayed on a own one of display portions of the screen, and a plurality of color assortment data each equivalent to a respective one of the display portions.

A sequence controller in sequence reads the pattern data chosen by the pattern name data and the color selection data in agreement with synchronization signals. A color collection control logic circuit selects one of the color information registers in harmony with the color selection data interpret from the memory, and reads one of the pair of color code data from the selected color in sequence register. A color signal generator generates a color signal in accordance with the color code data read from the register and provisions it to the video display unit.