A simple yet important fact that is unknown to most is that a CD can be burnt in multi-session. This means that all data (about 650 MB) to be written on the CD does not have to be written in one go, the CD-writer can add data to the CD as and when it is available. The process is similar to writing data on a floppy or even the hard disk. With CD media available for as little as Rs 15, it makes perfect sense to store data like MP3 songs, movie clips, installable software, large backups, etc on a CD rather than cluttering the hard disk. Unlike on a floppy disk, where data can be written and deleted at will, space on a CD used to write data once is consumed permanently. However, a re-writable CD media can be used about 2000 times to write and delete data. The CD-Rs can be put to several applications — the ability to create custom audio CDs on a CD-R has perhaps so far been the most commonly used application. But that is not all, write-once capability of CD-R media is well suited for archival applications where inability to erase data is a desirable feature. Earlier, CD-Rs allowed a single-session recording, forcing the user to complete the CD burning at one go without interruptions. This often led to problems like buffer under runs, caused by limited buffer memory, which terminated a recording session abruptly, leaving the CD-R disk unusable for future recording sessions. Packet writing, a feature supported by most good CD-R drives today, eliminates this hurdle by allowing smaller chunks of data to be written over multiple recording sessions. Another positive trend has been the growing support for the new standard file format (UDF version 1.5 or Universal Data Format). UDF packet writing software packages make a CD-R disk to appear as a drive letter or as an icon on the desktop for drag-n-drop capability. This makes a CD-R drive behave like any other attached drive. From a mere 2X write some time ago, CD-Rs
in the market today have a 16X capability. Yamaha’s CRW2100EZ for
example offers 16X write, 10X rewrite and 40X read capabilities. CD-Rs
like Plextor makes use of Sanyo’s Burn Proof Technology, while Yamaha
uses its own "Waste-Proof Write Strategy". This exclusive
write strategy maximises stability of the recording environment by
combining a large buffer memory. Yamaha drive has an 8 MB buffer. Some
CD-R drives also have DVD capabilities built-in like the Samsung’s
Combo drive. The modern CD-R drives use the laser sensing technology
that adjusts the laser beam on the writing media in a way that it
ensures flawless CD writing.
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