Disks and Other Peripheral Hardware
Read/write compact disk (CD-R) drives are now available at a price within the reach of the small recording studio, and recordable media are less than $2. CD-R drives are usually SCSI based so PCs usually have to have an extra expansion card fitted to provide this interface (see later). Recordable CDs rely on a laser-based magneto-optical system to “burn” data into the recorded medium. Once written, data cannot be erased. Software exists (and usually comes bundled with the drive) which enables the drive to be used as a data medium or an audio carrier (or sometimes as both). There exist a number of different variations of the standard ISO-9600 CD-ROM. The two most important are the (HFS/ ISO) Hybrid disk, which provides support for CD-ROM on Mac and PC using separate partitions, and the Mixed mode disk, which allows one track of either HFS (Mac) or ISO- 9600 information and subsequent tracks of audio.
A number of alternative removable media are available and suitable for audio use; some are based on magnetic storage (like a floppy disk or a Winchester hard-drive) and some on magneto-optical techniques—nearer to CD technology: Bernoulli cartridges are based on floppy disk, magnetic storage technology. Disks up to 150 MByte are available. Access times are fast; around 20 ms. SyQuest are similar. Modern SyQuest cartridges and drives are now available in up to 1.3 GByte capacity and 11-ms access times, making SyQuest the nearest thing to a portable hard drive. Magneto-optical drives use similar technology to CD, they are written and read using a laser (Sony is a major manufacturer of optical drives). Sizes up to 1.3 GBytes are available with access times between 20 and 30 ms.