pctechguide.com

  • Home
  • Guides
  • Tutorials
  • Articles
  • Reviews
  • Glossary
  • Contact

DVD-ROM

Like DVD discs, there is little to distinguish a DVD-ROM drive from an ordinary CD-ROM drive as the only giveaway is the DVD logo on the front. Even inside the drive there are more similarities than differences: the interface is ATAPI or SCSI for the more upmarket drives, and the transport is much like any other CD-ROM drive. CD-ROM data is recorded near the top surface of a disc. DVD’s data layer is right in the middle so that the disc can be double-sided. Therefore, the laser assembly of a DVD-ROM drive needs to be more complex than its CD-ROM counterpart, to enable it to read from both CD and DVD media. An early solution to entailed having a pair of lenses on a swivel: one to focus the beam onto the DVD data layers and the other for reading ordinary CDs. Subsequently, more sophisticated designs have emerged that eliminate the need for lens switching. For example, Sony’s dual discrete optical pickup design has separate lasers optimised for CD (780nm wavelength) and DVD (650 nm). Many Panasonic drives employ an even more elegant solution which avoids the need to switch either lenses or laser beams by use of a holographic optical element capable of focusing a laser beam at two discrete points.

DVD-ROM drives spin the disc a lot slower than their CD-ROM counterparts. However, since the data is packed much closer together on DVD discs, the throughput is substantially better than a CD-ROM drive at equivalent spin speed. While a 1x CD-ROM drive has a maximum data rate of only 150 KBps, a 1x DVD-ROM drive can transfer data at 1,250 KBps, which is just over the speed of an 8x CD-ROM drive.

DVD-ROM drives became generally available in early 1997 and these early 1x devices were also capable of reading CD-ROM discs at 12x speed – sufficient for full-screen video playback. As with CD-ROM, higher speed drives appeared as the technology matured. By the beginning of 1998, multispeed DVD-ROM drives had already reached the market, capable of reading DVD media at double-speed, producing a sustained transfer rate of 2,700 KBps, and of spinning CDs at 24-speed and by the end of that year DVD read performance had been increased to 5-speed. A year later performance had improved to six-speed (8,100 KBps) reading of DVD media and 32-speed reading of CD-ROMs. By late-2001 performance levels had reached 16-speed/40-speed for DVD-ROM/CD-ROM respectively.

There is no standard terminology to describe the various generations of DVD-ROM drive. However, second generation (or DVD II) is usually used to refer to 2x drives also capable of reading CD-R/CD-RW media and third generation (or DVD III) usually means 5x (or sometimes 4.8x or 6x) drives, some of which are capable of reading DVD-RAM media.

  • History of DVD development and birth of the DVD Forum
  • DVD Formats
  • DVDs – digital versatile disks – how they’re made and how they work
  • DVD OSTA
  • DVD File Systems
  • CDR-RW Compatibility Issues
  • DVD Encoding
  • DVD Content Protection
  • Regional codes for DVDs
  • DVD-ROM
  • DVD-Vdeo
  • DVD DivX Codec
  • DVD-Audio
  • DVD Recordable Formats
  • DVD-R – write once recordable DVDs
  • DVD-RAM
  • DVD+RW
  • DVD-RW
  • DVD+R
  • DVD Multi-Writers

Filed Under: DVD

Latest Articles

Effective Search on Google Drive

Google Drive is one of the most useful web apps available to them. Many view it just as storage, but it can do so much more. You can create documents, collaborate with other users and use it as cloud-based storage. One of the downsides, however, is finding files when you get several items in there. … [Read More...]

AMD 3DNow

With the launch of K6-2, in May 1998, AMD stole something of a march on Intel, whose similar Katmai technology was not due for release until up to a year later, in the first half of 1999. By the end of March 1999 the installed base of 3DNow! technology-enhanced PCs was estimated to have reached … [Read More...]

Lunar Sleep Review

So Lunar sleep has nothing to do with PC or tech stuff but sleeping problems effect 1 in 5 Americans.  Personally I think that is much higher as almost every tech person I know has trouble going to sleep. As our motto is We share what we learn I wanted to do a quick write up on sleeping better. I … [Read More...]

A Harsh Reality You Can’t Ignore About Network Information Security

We are becoming more and more connected to our lives with computer technology. They help to process data at work. We receive money using plastic … [Read More...]

What is the Best VPN for Gamers?

Of the 44% of UK Internet users who have used a virtual private network (VPN) at some point in their lives, approximately 39% of this demographic are … [Read More...]

Think About Headless Commerce as of a Modular System

In recent years, eCommerce has transformed to where consumers no longer handle purchases on conventional websites. Shopping is currently carried out … [Read More...]

Service That Succeeds: How To Build an Effective IT Service Desk

In today’s tech-forward world, building a capable IT service team is essential for businesses hoping to scale tech-related hurdles and soar past the … [Read More...]

A simple PC guide on keeping safe while using public Wi-Fi

Did you know that there is a cyberattack every 39 seconds? You are more likely to be a victim if you are lax about your digital security. This … [Read More...]

Motivating Students to Learn Computer Science

Computer science has been an important part of the educational curriculum for decades. Professor Seymour Papert, a mathematician from South Africa … [Read More...]

Guides

  • Computer Communications
  • Mobile Computing
  • PC Components
  • PC Data Storage
  • PC Input-Output
  • PC Multimedia
  • Processors (CPUs)

Recent Posts

Excel Shortcuts for More Complicated Commands

We previously wrote an article on the benefits of using keyboard shortcuts in Excel. The shortcuts we focused on were used for simple formatting … [Read More...]

DVD File Systems

One of the major achievements of DVD is that it has brought all the conceivable uses of CD for data, video, audio, or a … [Read More...]

Digital Video Format

In the late 1990s a new generation of entirely digital cameras and camcorders emerged, and with it a … [Read More...]

[footer_backtotop]

Copyright © 2022 About | Privacy | Contact Information | Wrtie For Us | Disclaimer | Copyright License | Authors