NWA-PCUG 05/2000 NewsLetter Article 18861 N. Hwy 112, Springdale, AR 72762-9303 Please notify Surya Singh via electronic or US Mail if this article is used. There is no restriction against anyone using the article as long as it is kept in context, with proper credit given to the author. Surya Singh, 600 Fernwood Road, Knoxville TN 37923 spns@utk.edu Will CD-R and CD-RW Become the "Floppy of the Future"? Ten years ago the common method of sharing files was via a square piece of plastic, five and a quarter inches in diameter. This "floppy" disk held either 360 kilobytes or 1.2 megabytes depending on which type was being used. With todays ever increasing need for removable storage however, CD-R and CD-RW, may become as popular as the floppy disk was in its heyday. CD-R and CD-RW are acronyms that stand for Compact Disc-Recordable and Compact Disc ReWriteable respectively. Both CD-R and CD-RW drives are extensions to the standard CD-ROM (Compact Disc Read Only Memory) drive format found in most every computer. These two systems are related to each other and present the consumer with a wide number of upgrade choices in this brave new world. The key feature of CD-R and CD-RW drives over their now commonplace relative the CD-ROM drive is their ability to write data to a disc. CD-R media can be written once only to any particular area on the disc. CD-RW drives build on the CD-R standard and allow the user to write and rewrite to any particular area on a CD-RW disc many times. Most CD recordable drives available today have rewriteable features and can process both CD-R and CD-RW media. However, a CD recordable must have rewriteable features to rewrite CD-RW discs. In other words, a CD-RW drive can only rewrite CD- RW media (not a CD-R discs) and a CD-R only drive can not process CD-RW media. One of the cavets with CD-R media is that once its has been written or marked it can never be erased. Thus, working with CD-R media is quite similar to writing everything with a permanet ink pen: Nothing can ever be erased. Moreover, if a mistake is made, the whole process must be restarted and the erroneous disc is simply trashed. It was because of this vexing problem that CD-RW technology, using phase-change media was developed. CD-R and CD-RW drives, unlike most drives, can record in a variety of formats, each of which effects the final utility of the finished disc. The most common CD-R and CD-RW formats are discussed as follows: 1. The Packet Writing Format - This means of using the disc allows for the disc to easily act as a removable media drive. If CD-RW media is used, the drive responds and acts as a diskette or Zip drive would. However, the disc first needs to be formated to the UDF format style which reduces the storage capacity to approximately 550 MB. CD-R packet written discs can be read by any CD-ROM drive as long as they are at least "temporarily closed." If the UDF drivers are installed on a PC, a CD-RW packet written disc can be read by most modern CD-ROM drives as long as they support packet reading. 2. Standard Data Track Format - This means creates a CD data disc similar to most CD-ROM disc distributed with software. This format allows the user to store the full 640 MB that the disc can hold; however, the disc data must be processed using a CD recording application (e.g., Adaptec's CD Creator) and can not be written to directly. 3. The Audio Track/Multisession Format - This is the standard means that digitalized forms of audio are added to CD discs. However, each time a series of songs is recorded, a new session is created. For a "multisession" to be read, the CD player must support the multisession format Why is CD recording such a complex system? Basically, it stems from the history of CD technology. CD technology was invented by Phillip's Electronics and others almost two decades ago. The original CDs started out as an optical incarnation of long-playing vinyl records (LPs). For this reason CDs, unlike diskette and hard drives, read/write along a continuous, spiraling track instead of sectors. This causes the drives to vary their speed as data is read at various points on the disc because on the outside, more "media" goes by for a given angular velocity. However, data storage is best done using a sector or packet based approach and not the spiral-track approach of CDs. To accommodate data, CDs often place all their data in the first "track" along with a Table of Contents that stores information about all the files and where they are located. Even the speed ratings of most drives are a product of CD history as drive multipliers (e.g., 8x) are in proportion to the speed of the first drives that operated at a rate of 150 kilobytes per second. Another reason for the great popularity of CD recorders is their economies of scale, which makes them extremely cost competitive for the storage of a large amount of data. CD-R discs or media cost about one dollar per disc and CD-RW discs are approximately $5 dollars a disc. This results in exceptionally low unit costs, or cost per megabyte (measured in ¢/MB). CD- R discs have a unit cost of less than 1/6 ¢/MB and CD-RW disc have a unit cost near 1 ¢/MB. In comparison, hard drives have a unit cost ranging between 3 and 6 ¢/MB and Iomega Zip disks have a unit cost almost 100 times greater than CD-R (i.e, 12 ¢/MB). In addition to cost, CD-R and CD- RW are gaining popularity because of their backward compatibility with the CD-ROM standard. This allows distribution of data on CD-R discs to a wide number of users without having to worry if the user has the right drive to read the media. CD-R and CD-RW systems however,are not perfect. One key disadvantage is that CD-R and CD-RW drives can be somewhat expensive. For example, CD-RW drives range from $200 to $400 depending on the drive's speed and interface. A second disadvantage with CD-R and CD-RW drives is that they are relatively slow. Most of these drives operate only two or four times the speed of the original CD-ROM specification. Thus, even the fastest CD recorders are 10-15 times slower (while writing) than a hard drive and 2-3 times slower than CD-ROM readers. In terms of marketability and support, CD-R and CD-RW have not seen a major advertising campaign (excluding a small campaign by Philips electronics) nor have they been endorsed by any major computer vendor. Nonetheless, CD-R and CD-RW drives have generated a great deal of end user support and are increasing tremendously in popularity. Since CD-R and CD- RW are not proprietary standards, there is a great deal of competition between a number of CD-R and CD-RW manufacturers. This competition should not only lower the prices on the drives, but may help CD-R and CD-RW become more widely accepted in the computing industry. In summary, the complexity of today's software and the data files associated with it, has grown exponentially. One of the most promising and cost effective solutions could be the CD-R and CD-RW system. However, for this technology to "replace the floppy" the price of the drives must come down and performance must be increased. This article is brought to you by the Editorial Committee of the Association of Personal Computer User Groups (APCUG), an International organization to which this user group belongs. Surya Singh is a member and SIG leader of the East Tennessee Computer Society in Knoxville Tennessee. Please notify Surya Singh via electronic or US Mail if this article is used. There is no restriction against anyone using the article as long as it is kept in context, with proper credit given to the author. Surya Singh, 600 Fernwood Road, Knoxville TN 37923 spns@utk.edu