Writable CDs
Although the CD originally was conceived as a read-only device, these days you easily can create your own data and audio CDs. By purchasing CD-R or CD-RW discs and drives, you can record (or burn) your own CDs. This enables you to store large amounts of data at a cost that is lower than most other removable, random-access mediums.
It might surprise newcomers to the world of PCs to see just how far recordable CD technology, performance, and pricing has come. Today you can buy recorders that operate at up to 52x speeds and cost under $100. You can even purchase Slimline CD drives for laptops.
Compare this to the first CD-R recording system on the market in 1988, which cost more than $50,000 (back then, they used a $35,000 Yamaha audio recording drive along with thousands of dollars of additional error correction and other circuitry for CD-ROM use), operated at 1x speed only, and was part of a subsystem that was the size of a washing machine!
The blank discs also cost about $100 each—a far cry from the 25 cents or less they cost today (if you purchase in bulk and are willing to supply your own jewel cases). With prices that high, the main purpose for CD recording was to produce prototype CDs that could then be replicated via the standard stamping process.
In 1991, Philips introduced the first 2x recorder (the CDD 521), which was about the size of a stereo receiver and cost about $12,000. Sony in 1992 and then JVC in 1993 followed with their 2x recorders, and the JVC was the first drive that had the half-height 5 1/4'' form factor that most desktop system drives still use today.
In 1995, Yamaha released the first 4x recorder (the CDR100), which sold for $5,000. A breakthrough in pricing came in late 1995 when Hewlett-Packard released a 2x recorder (the 4020i, which was actually made for them by Philips) for under $1,000. This proved to be exactly what the market was waiting for.
With a surge in popularity after that, prices rapidly fell to below $500, and then down to $200 or less. In 1996, Ricoh introduced the first CD-RW drive. Compared with either tape or other removable media, using a CD burner is a very cost-effective and easy method for transporting large files or making archival copies.
Another benefit of the CD for archiving data is that CDs have a much longer shelf life than tapes or other removable media. Two main types of recordable CD drives and discs are available, called CD-R (recordable) and CD-RW (rewritable).
Because all CD-RW drives can also function as CD-R drives, and the prices of CD-R and RW drives are similar, virtually all drives sold today are CD-RW. Those drives can work with either CD-R or CD-RW discs. In addition, because the CD-RW discs are 1.5–4 times more expensive than CD-R discs, only half as fast (or less) as CD-R discs, and won't work in all CD audio or CD-ROM drives, people usually write to CD-R media in their CD-RW drives.
CD-R media is a WORM (write once, read many) media, meaning that after you fill a CD-R with data, it is permanently stored and can't be erased. The write-once limitation makes this type of disc less than ideal for system backups or other purposes in which it would be preferable to reuse the same media over and over.
However, because of the low cost of CD-R media, you might find that making permanent backups to essentially disposable CD-R discs is as economically feasible as tape or other media. CD-RW discs can be reused up to 1,000 times, making them suitable for almost any type of data storage task. When first introduced, there were many CD-R-only drives; however, today most recordable CD drives are both CD-R and CD-RW in one.