PC Data Storage

PC DATA DATA STORAGE

Bill Gates is often credited with the quote, "640K ought to be enough for anybody." It was said inreference to computer memory in 1981, clearly illustrating how computer data volume has increased. Bill, in his defense, denies that he ever said it...This section of the PCTechGuide explains the technology behind computer storage media.

The detailed explanations of everything from a CD to a USB stick are often accompanied by background insights into how over time the industry has fought - sometimes literally - to cope with the pace of demand.

Hard Disks

The hard disk has to provide reliable storage for huge amounts of data, and provide fast access. Get an insight from early development through solutionslike RAID to modern solid state drives.

When the power to a PC is switched off, the contents of memory are lost. It is the PC's hard disk that serves as a non-volatile, bulk storage medium and as the repository for a user's documents, files and applications. It's astonishing to recall that back in 1954, when IBM first invented the hard disk, capacity was a mere 5MB stored across fifty 24in platters. 25 years later Seagate Technology introduced the first hard disk drive for personal computers, boasting a capacity of up to 40MB and data transfer rate of 625 KBps using the MFM encoding method. A later version of the company's ST506 interface increased both capacity and speed and switched to the RLL enco

din

g method. It's equally hard to believe that as recently as the late 1980s 100MB of hard disk space was considered generous. Today, this would be totally inadequate, hardly enough to install the operating system alone, let alone a huge application such as Microsoft Office.

Blu-ray Disks

Blu-ray is the next generation optical disk technology for the new millennium. Using revolutionary blue-violet laser technology, it provides a medium for

high definition video and now 100GB of data storage.

Blu-ray Disc (BD) is the name of a next-generation optical disc format jointly developed by members of the Blu-ray Disc Association (BDA). The format was developed to enable recording, rewriting and playback of high-definition (HD) video, as well as storing large amounts of data. It became the sole blue laser optical disc technology in 2008, when the rival format HD-DVD was finally dropped by Toshiba.

In the late 20^th Century, optical disc technology developed from the groundbreaking CD (Compact Disk) in the 1980s to the next generation DVD (Digital Versatile Disk) in the early 1990s. Ar

guably, despite some initia

l scepticism, the CD had performed well in the market as a medium for music and date storage. However its successor, the DVD, had troubles from the start. Both the data and multimedia applications of DVDs were beset with rows between the major technology developers, leading to consequent

compatibility problems for consumers.

Portable RAM - Flash Drives, RAM Sticks and Memory Sticks

Solid state devices provide excellent portable file media, particularly for cameras, phones, and MP3 players. As a ready medium for file transfer between home and office or the classroom, a handy USB stick's hard to beat.

Portable devices using solid state RAM can hold data for long periods, either as a backup for safekeeping or to transfer data between systems. Solid state RAM re

members the state it's been set to when the power is removed, as opposed to the RAM used in PCs, which is wiped clean every time the PC is shutdown. There are two main forms in use, USB flash drives or memory cards.

DVD/CD ROM

After a shaky start, DVDs eventually raised the bar with writable, portable disk media.

After a lifespan of ten years, during which time the capacity of hard disks increased a hundred-fold, the CD-ROM finally got the facelift it required to take it into the next century when a standard for DVD (initially called digital video disc but eventually known as digital versatile disc) was finally agreed during 1996.

The movie companies immediately saw what was essentially a high capacity CD as a way of stimulating the then struggling video market, producing better quality sound and pictures on a disc that cost considerably less to produce than a VHS tape. Using MPEG-2 video compression, the same system used for digital TV, satellite and cable transmissions, it was quite possible to fit a full-length movie onto one side of a DVD disc. With picture quality as good as live TV, the DVD-Video disc can also carry multi-channel digital sound, opening up home entertainment systems for surround sound hi-definition audio.