Storage Device/Multimedia

Storage Devices

Storage Device/Multimedia Storage Devices

The function of storage in a computer comes in many different sizes, types and shapes. Each type of computer memory serves a specific function and purpose.

MEMORY

The two fundamentals types of a Memory in a Computer System 1. Main Memory 2. Secondary MemoryTwo basic categories or term: short-term and long-term.Short-term RAM Virtual cacheLong-term ROM Computer memory is measured in bytes. A byte is made up of 1’s and 0’s normally traveling in pairs of eight. These 0’s and 1’s are the way the computer communicates and stores information. With each keystroke or character a byte of memory is used.

Measuring Memory

Character S p a c i n g

Kerning

Strikethrough

Styled Underline

Effects

Term/ Byte Abbreviation Value

Kilo K, KB 1,024 bytes

Mega M, MB, Meg 1,048,576 bytes (Million)

Giga G, GB, Giga 1,073,741,824 bytes (Billion)

Tera T, TB, Tera 1,099,511,628,000 bytes (Trillion)

Here is another way of looking at the measurement of memory:

Measuring Bytes

8 Bits = 1 byte

1000 bytes = 1 kilobyte

1000 kilobytes = 1 megabyte

1000 megabytes = 1 gigabyte

1000 gigabytes = 1 tetra

ROM

ROM, or read-only memory is permanent, long-term, nonvolatile memory. Nonvolatile means is doesn't disappear when the computer is shut off. It also can not be erased or changed in anyway. However there are types of ROM called PROM that can be altered. The P stands for programmable. ROM's purpose is to store the basic input/output system (BIOS) that controls the start-up, or boot process.

RAM

RAM, or random-access memory unlike ROM works only when the computer is turned on. This memory is vital to the computer because it controls the moment by moment processes of the computer. The first thing that goes into RAM is the OS (operating system) which is most cases is Windows 95. Next for the RAM might be a game, or the Internet browser, or some type of software that you want to use.

Other types of temporary memory are cache (pronounced "cash") and virtual memory. Both of these types of memory supplement the computer's primary RAM and perform the same function as RAM.

Secondary Memory – is where programs and data are kept on a long-term basis.

Here are the most common forms of Long term Storage Devices.

Floppy disk or Floppy or FDD

A round plastic surface that is coated with magnetic film. They come in 31/2 size. They hold about 720k to 1440K of information. They are typically are used to install new software, save, share, and/or copy files. Floppy drives are given letters. Commonly the floppy is A, a 2ndfloppy is B and the hard drive is C.

Hard disk (drive) or HD

A stack of round metal platters called disks encased in a metal air tight shell. They commonly range in sizes from 1 to 10 gigabytes (1000MB=1GB). The hard drive's function is to store all the files, and software the computer will ever use. Any file or software program used by RAM most likely will come from the disk drive. CD-ROM (Compact disk, read-only memory)

CD's function much like hard drive in that they store large amounts of memory. What separates them is their mobility and optical storage technology. Their storage capacity is also very limited compared to hard drives. The can only hold up to approximately 650 MB of information. The other big difference is that you have to have a special drive to write to CD's. Otherwise they can only be read from.

DVD's are similar to CD in that they are written and read by laser. Hard drives use magneticcurrents store data. However CD's and DVD's use light (laser) to write and read data on a disk.These long and short pits are then stored or etched on the surface of the disk. They can only beread by laser technology. The new DVD technology increased the amount of memory a regular CDcan hold. DVD's can range in sizes from 4.34GB (1000MB=1GB) to 7.95GB.

DVD-ROM (digital video disk, read-only memory)

Three formats were developed: -R/RW (minus), +R/RW (plus), -RAM (ram).

DVD ROM (also known as "Digital Versatile Disc" or "Digital Video Disc") is an optical discstorage media format that can be used for data storage, including movies with high video and soundquality. DVDs resemble compact discs as their physical dimensions are the same (120 mm (4.72inches) or occasionally 80 mm (3.15 inches) in diameter) but they are encoded in a different formatand at a much higher density.

Dual Layer recording allows DVD-R and DVD+R discs to store significantly more data, up to 8.5

Gigabytes per disc, compared with 4.7 Gigabytes for single-layer discs. DVD-R DL.

.

BLU-RAY ROM Blu-ray Disc (also known as Blu-ray or BD) is

an optical disc storage medium designed bySony to supersede the standard DVD format. Its

main uses are for running Playstation 3 games,high-definition video and data storage with 50GB

per disc. The disc has the same physicaldimensions as standard DVDs and CDs.The name Blu-ray Disc derives from the blue-

violet laser used to read the disc. While a standard

DVD uses a 650 nanometre red laser, Blu-ray uses a shorter wavelength, a 405 nm blue-violet laser,

and allows for almost six times more data storage than on a DVD.

Hardware Components of Storage DeviceCD and DVD

Blu-ray Disc (BD) is an optical disc storage medium designed to supersede the DVD format. The plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs and CDs. Conventional (pre-BD-XL) Blu-ray Discs contain 25 GB per layer, with dual layer discs (50 GB) being the industry standard for feature-length video discs. Triple layer discs (100 GB) and quadruple layers (128 GB) are available for BD-XL re-writer drives.

Common transfer speeds

Transfer speed Megabytes/s Megabytes

1x 0.05 1.2

2x 0.3 2.4

4x 0.6 4.8

8x 1.2 9.6

10x 1.5 12.0

12x 1.8 14.4

20x 3.0 24.0

32x 4.8 38.4

36x 5.4 43.2

40x 6.0 48.0

48x 7.2 57.6

50x 7.5 60.0

52x 7.8 62.4

Data Transfer Speeds

Power Supply Connector

SATA connector

CONNECTORS FOR PERIPHERALSIDE (Integrated Drive Electronics Interface)

- A hard disk interface standard used for disk in the rage of 40MB to 1.2

GB, requiring medium to fast data transfer rates. IDE cables consist of either 40 individual wire or 80 individual wires.

1)40 conductor IDE Ribbon cable (for CD ROM / DVD ROM)2)80 conductor IDE Ribbon cable (for Hard Disk Drive or HDD)3)Floppy Disk Ribbon Cable( notice a red or blue, white stripe of wire)4)SATA Cable ( for SATA Hard Disk and DVD Writer)

Types of IDE Cables

SATA CABLE

Internal to external SATA connector “L” TYPE

Parallel ATA (PATA) is an interface standard for the connection of storage devices such as harddisks, solid-state drives, and CD-ROM drives in computers. The standard is maintained byX3/INCITS committee[1]. It uses the underlying AT Attachment and AT Attachment PacketInterface (ATA/ATAPI) standards.

The current Parallel ATA standard is the result of a long history of incremental technical development. ATA/ATAPI is an evolution of the AT Attachment Interface, which was itself evolved in several stages from Western Digital's original Integrated Drive Electronics (IDE) interface. As a result, many near-synonyms for ATA/ATAPI and its previous incarnations exist, including abbreviations such as IDE which are still in common informal use.

Serial ATA was designed to replace the older ATA (AT Attachment) standard (also known asEIDE). It is able to use the same low level commands, but serial ATA host-adapters and devicescommunicate via a high-speed serial cable over two pairs of conductors. In contrast, the ParallelATA (the redesignation for the legacy ATA specifications) used 16 data conductors each operatingat a much lower speed.

The Serial ATA, or SATA, computer bus is a storage-interface for connecting host bus adapters to mass storage devices such as hard disk drives and optical drives. The SATA host adapter is integrated into almost all modern consumer laptop computers and desktop motherboards.

SATA offers several compelling advantages over the older parallel ATA interface: reduced cable-

bulk and cost (reduced from eighty wires to seven), faster and more efficient data transfer, full

duplex (the ability to transmit and receive at the same time), and hot swapping (the ability to remove

or add devices while operating).

Serial ATA - or simply SATA - is the new hard disk standardThey only have two channels:a) one receiving datab) one transmitting them.This can be achieved with a very simple cabling. The data

communication only requires 0,25 Voltcompared to the 5 Volt of parallel ATA.