This might help you Vishal knowing about DVDRAM

[abhinavsharma]

Currently there are three competing technologies for rewritable DVDs: DVD-RAM, DVD+RW and DVD-RW.
DVD-RAM is considered a highly reliable format, as the discs have
built-in error control and a defect management system. Therefore,
DVD-RAM is perceived to be better than the other DVD technologies for
traditional computer usage tasks such as general data storage, backup
and archival, though the Mt. Rainier
standard for DVD+RW somewhat lessens the DVD-RAM format's perceived
advantage. Curiously, DVD-RAM has a larger presence in camcorders and
set-top boxes than in computers, although the DVD-RAM's popularity in
these devices can be explained by the fact that it is very easily
written to and erased, which for example allows extensive in-camera
editing.
The on-disc structure of DVD-RAMs is closely related to hard disk and floppy disk technology, as it stores data in concentric
tracks. DVD-RAMs can be accessed just like a hard or floppy disk and
usually without any special software. DVD-RWs and DVD+RWs, on the other
hand, store data in one long spiral
track and require special packet reading/writing software to read and
write data discs. It is a common misconception that DVD-RAM uses magneto-optical (MO) technologies, since both DVD-RAM and MO have numerous rectangles on the disc surface. However, DVD-RAM is a pure phase change medium, similar to CD-RW or DVD-RW.
See also DVD, Compact Disc.

[edit] DVD-RAM Cartridge types


SizeBare DiscNon-removable CartridgeRemovable CartridgeEmpty/No Cartridge

sides	single	double	single	double	single	double	single	double
12 cm	yes (type 0)	none	type 1	type 1	type 2	type 4	type 3	type 5
8 cm	yes (type 0)	none	none	none	type 7	type 6	type 9	type 8

[edit] Specification



A DVD-RAM Type 2.






A DVD-RAM for DVD Recorders





Since the Internationale Funkausstellung Berlin 2003 the specification is being marketed by the RAM Promotion Group (RAMPRG), built by Hitachi, Toshiba, Maxell, LG Electronics, Matsushita/Panasonic, Samsung and Teac.
The specification distinguishes between

• DVD-RAM version 1.0, recording speed 1x
  
  
  
  • Single-sided, one layer discs with a capacity of 2.58 GB
    
  • Double-sided one layer discs with a capacity of 5.16 GB
    
  
  


• DVD-RAM version 2.0, recording speed 2x
  
  
  
  • Single-sided, one layer discs with a capacity of 4.7 GB
    
  • Double-sided one layer discs with a capacity of 9.4 GB
    
  
  


• DVD-RAM version 2.1/Revision 1.0, recording speed 3x
  
• DVD-RAM version 2.2/Revision 2.0, recording speed 5x
  
• DVD-RAM version 2.3/Revision 3.0, recording speed 6x max
  
• DVD-RAM version 2.4/Revision 4.0, recording speed 8x max
  
• DVD-RAM version 2.5/Revision 5.0, recording speed 12x max
  
• DVD-RAM version 2.6/Revision 6.0, recording speed 16x max
  

Physically smaller, 80 mm in diameter, DVD-RAM discs also exist with
a capacity of 1.46 GB for a single-sided disc, but they are uncommon.
DVD-RAMs were originally solely sold in cartridges;
recent DVD recorders however also work with no-cartridge discs — some
devices even do not support cartridges anymore. A cartridge disc is
about 50% more expensive than a disc without a cartridge.

A miniDVD-RAM with DVD Round Holder.




How to open DVD-RAM cartridge






[edit] Compatibility


Many operating systems like Mac OS (Mac OS 8.6 up to Mac OS 9.2), Linux and Microsoft Windows XP support DVD-RAM operation directly, while earlier versions of Windows require device drivers or the program InCD. The optical drives shipped with most Apple Macintosh computers do not support DVD-RAM operation, but a third party DVD-RAM-compatible drive can be connected and used directly with Mac OS.
Windows XP can only write directly to FAT32-formatted DVD-RAM discs. For UDF-formatted discs, which are considered faster, compatible device drivers or software such as InCD or DLA are required. Windows Vista
can natively access and write to UDF-formatted DVD-RAM discs. This is a
non-issue with Linux however, which allows the use of virtually any
file system of the multitude that ship with the operating system,
including UDF. It is even possible to use the ext3
file system on a DVD-RAM disc. Even though it is possible to use any
file system one likes, only very few perform well on DVD-RAM. This is
because some file systems frequently over-write data on the disc and
the table of contents is contained at the start of the disc.
Mac OS up to 9.2 (Mac OS Classic) can read and write HFS-, HFS Plus-, FAT-, and UDF-formatted
DVD-RAM discs directly. Although Mac OS X does not officially support
any DVD-RAM formatting or writing operations, it is reported that it is
possible to use some third-party DVD-RAM drives to format, read and
write HFS Plus- and FAT32- disks (for instance see [1]).
Many DVD standalone players and recorders do not support DVD-RAM,
especially older or cheaper versions. However, within "RAMPRG" (the
DVD-RAM Promotion Group) there are a number of well-known manufacturers
of standalone players and recorders that do support DVD-RAM. Panasonic
for instance have a range of players and recorders which make full use
of the advantages of DVD-RAM. There are also a number of video cameras
that use DVD-RAM as the recording media.
The newest DVD-RAM Specification, DVD-RAM2 (also called RAM2), is
not compatible with DVD drives that do not specifically support reading
DVD-RAM discs.

[edit] Evaluation



[edit] Advantages of DVD-RAM

• Long life — without physical damage, data is retained for an
  estimated 30 years minimum. Ideal for video evidence recording in CCTV
  applications amongst many other uses.
  
• Can be rewritten over 100,000 times (DVD±RW can be rewritten
  approx. 1,000 times). Faster DVD-RAMs support fewer rewrites (3x speed:
  100,000, 5x speed: 10,000)^{[citation needed]}, but still more than DVD+RW or DVD-RW.
  (These are theoretical numbers. In practice they could be smaller
  depending on the drive, the treatment of the disc and the file system.)
  
• Reliable writing of discs. Verification done in hardware by the
  drive, so post-write verification by software is unnecessary. Software
  verification is disabled in all current DVD Video Recorders.
  
• Disc defect management safeguards data, though no optical phase change media is suitable for long term archiving.
  
• DVD-burning software may not be required — discs can be used and accessed like a removable hard disk. Mac OS (8.6 or later) supports DVD-RAM directly. Windows XP
  supports DVD-RAM directly only for FAT32-formatted discs. Windows Vista
  is able to write to both FAT32- and UDF-formatted DVD-RAM discs right
  from within Windows Explorer. Device drivers or other software are
  needed for earlier versions of Windows or if one wants to use the
  arguably better UDF format rather than FAT32.
  
• Arguably easier to use than other DVD technology.
  
• Very fast access of smaller files on the disc.
  
• 2 KB disc block size wastes less space when writing small files.
  
• Finalization not necessary. This is an attribute of the VR mode recording mode and is available on other media such as DVD-RW.
  
• Media available with or without protective cartridges.
  
• In video recorders, DVD-RAM can be written to and watched (even separate programs) at the same time, much like TiVo.
  This is an attribute of the VR mode recording mode and is available on
  other media such as DVD-RW, though this is only possible at the lower
  bit rates.
  
• Supports time slip recording and recording without border in/out writing. This is an attribute of the VR mode recording mode and is available on other media such as DVD-RW, though again only at the lower bit rates.
  
• Supported by some high end security digital video recorders, such
  as the Tecton Darlex, as a secure export medium. 30 year retention
  makes this an ideal format for evidence.
  
• Holds more data when using Double Sided discs than dual-layer
  DVD+RW and DVD-RW, 9.4GB for DVD-RAM vs 8.5GB for DVD+RW DL and DVD-RW
  DL.
  

[edit] Disadvantages of DVD-RAM

• Less compatibility than DVD+RW and DVD-RW, despite predating both formats (as noted above).
  
• 12x media is reportedly available at OpticStor in the USA. It is
  not reportedly available in Europe. 16x media may not be available
  anywhere except manufacturers' R&D laboratories.
  
• DVD-RAM media was initially more expensive than other DVD types.
  
• DVD-RAM writing will be slower than DVD+RW and DVD-RW until 12x
  DVD-RAM media becomes available. If write verification is enabled,
  corders and drives, but the media itself is further hindered by its scarcity at retail stores in contrast to other recordable DVD formats.
  

[abhinavsharma]

What are Portals and Vortals?



Many of
the big well known sites are considered portals. They are gateways into
the internet for many users. A Portal attracts a broad (horizontal)
range of users whereas Vortals appeal to a more narrowed (vertical)
audience.
Vortals - The online Community



Vortals focus on a group of people with a specific passion or interest.
They are sometimes called 'online communities' or ' vertical portals.'
If you are interested in horses, for example, go to horsenet.com. Here
you can chat with others interested in horses. You can also buy
horse-related products and books and find information about horses.

How can we help you?


We can build your Portal, Vortal or Community. Portal development may
include adding several features or components that are not normally
found on a typical site. For example, you may need a discussion forum
so that your visitors can share ideas or experiences. Creating this
forum requires deciding which forum software to use and then installing
it on the server. There are many other components or modules you may
wish to add to your Portal / Vortal. The following table lists out a
few-

Credit Card Processing	E-commerce or online purchase of products or services
Chat	This allows users to chat online
Calendar	Show tour events or let users post events
Search	Keyword or phrase search of the whole site
Classified Ads	Allow users or members to post their own classified ads
Rotate Banner Ads	This component displays ads for a specified time on each page
Application Form	Visitors can complete an application and send it
Shopping Cart	Select a product online and drop it in a cart for purchase
Quiz	Use it for an online course or fun
Survey and Poll	Get helpful information about visitors
Links	Allow visitors to add their favorite links

Administering your portal


Installation
of the script component is only the first step. It takes some time to
learn how to administer it. For example, in the case of discussion
forums, setting up the topics and discussion areas is involved. After
setup, ongoing control over the discussion is needed. Many people are
surprised that a good Portal is an ongoing process. Once it is
designed, developed and published, the Portal needs visitors. This
requires site promotion. Also the site will become obsolete and
stagnant unless it is updated and maintained.
COMPONENTS OF PORTAL DEVELOPMENT

• 
  Concept, design and text development
  
• 
  Site development
  
• 
  Installation of components: CGI/ Perl scripts
  
• 
  Graphic and animation development
  
• 
  Banner ad creation
  
• 
  Updating/ improving content
  

TURNKEY PORTAL PACKAGE


Here
is a quick and easy way to get your online community up and running.
You describe what you want to accomplish and we can create a simple
portal containing the following:

• 
  Home Page - including 3 extra pages.
  
• 
  Form - 1 feedback form which will be e-mailed to you each time someone fills it in.
  
• 
  Discussion Forum - Here your visitors can post questions and comments. This is the heart of the community.
  
• 
  Links - This allows visitors to add links to your site. It is similar to Yahoo! or other search engines.
  
• 
  Survey - Use this to get customer feedback while at the same time provide spontaneous way to view compiled results.
  
• 
  Poll - Many people like to know the opinion of others.
  
• 
  Banner Ads - Advertise your products or receive income from others. We will create two banners ads for you.
  
• 
  Search - Allow your visitors to search your site for words.
  
• 
  Site Promotion
  - We will promote your site, otherwise you may have a beautiful site
  with no visitors. We will get your site listed on some of the major
  search engines like Alta Vista, Looksmart, Excite, Lycos and others.
  
• 
  Site Statistics - We will set you up so that you can easily monitor the number of visitors coming to your portal.
  
• 
  Handbook - These instructions will help you to keep your site going after we have created it.
  

SIMPLE VORTAL PLUG-IN PACKAGE


We
will plug these features into your existing site. We call this the
vortal plug-in because it is a simple inexpensive way to start a
vortal.

• 
  Guest Book - Here your visitors can post their names and comments.
  
• 
  Survey - Get customer feedback
  
• 
  Search - Allow your visitors to search your site for words.
  
• 
  Form - Your visitors can complete a form and submit it to you.