Sun CD-ROM FAQ: Using a CD-ReWritable (CD-RW) drive on a Sun workstation

CD-RW is CD-ReWritable, previously called CD-Erasable. It is a new optical disc specification baptized by the industry organization OSTA (www.osta.org). Basically, where CD-ROM was Read Only (RO) and CD-R is Write Once, Read Many (WORM), CD-RW is Read and Write and Overwrite (erase) access to an optical disc.

So CD-RW could be considered a superset of CD-R functionality. CD-R and CD-RW media are not the same as CD-ROM media, because the contents of the disc must be writable by a laser. Furthermore, CD-R and CD-RW media reflectivity is lower than CD-ROM media. Hence, CD-R and CD-RW media may not be readable by every CD-ROM drive. Multiread is the new specification for any optical drive to read the new CD-R and CD-RW media, vendors are begining to adopt it into CD-ROM drives.

CD-RW drives are SCSI devices that can function as a CD-ROM as well as a hard drive.

Thanks to Mark Lavi <marklavi@bayarea.net> for the information. Mark has reported to me that he has a Mitsubishi Chemical CD-RW drive connected to his Ultra workstation presently operating as a CD-ROM drive.

How does one use CD-RW?

You can hook up the drive as SCSI device ID 6 (the standard SCSI ID for a CD-ROM drive on a Sun workstation) and it will function as a CD-ROM drive, but not as a SCSI hard drive. You'll need to change the device ID to another number and reboot your system, then configure the drive as a new device and disk. This will allow you to write UFS or PCFS onto it. (I'm trying to do this right now, I believe it is correct, but until I'm sucessful, these last two sentences are unverified.)

You can use commercial software to "master" the CD media: to write other file systems and formats, such as CD-ROM (ISO9660v.3 or High Sierra format), CD-Audio, CD-I, etc. to allow the media to be read in other multisession CD devices.

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