For fast access to data stored on numerous CDs, consider one of the changers now available that can hold up to 18 CD-ROMs. Three new changers are built using mechanisms from Pioneer New Media Technology. The Magic CD 6 Quadraspin is available from MacProducts USA. It sells for $1099 and can hold six CDs. It and Pioneer's $1845 DRM-1804X are quadruple-speed drives, although the Pioneer can handle 18 CDs. Pioneer's DRM-602X uses a slower, double-speed mechanism, and it's able to handle 6 CDs.
Device drivers identify multiple CDs in the CD changer through different drive letters. When you access a CD, the drive mechanism moves up or down to align itself with the desired CD, draws the CD into place, and locks it for reading. The amount of time changing CDs varies depending on the CD location in the
CD changer. We measured the time to change from CD 1 to CD 6 and then displayed the directory on that CD (see the chart below). The quadruple-speed Pioneer completed this task fastest (just over 8 seconds), while the double-speed Pioneer and quadruple-speed Magic CD required 9.46 and 9.26 seconds, respectively.
Key Terms
CD-I (CD Interactive)
A format developed by Philips for the playback of multimedia and interactive software.
ISO-9660
A pervasive file-format standard created by the ISO.
CD-ROM XA (Extended Architecture)
XA-compatible drives offer multisession playback and synchronization of various media types.
MPC Level 2
The Multimedia Marketing Council's standard for minimum multimedia system requirements.
Multisession recording
Recording data in more than one session, with a table of contents for each session.
Photo CD
A standard specific to Eastman Kodak's Photo CD storage media.
Session
Recording data and creating a table of co
ntents on a blank CD.
Single-session recording
Recording an entire set of data on a CD at one time. No more than one table of contents is allowed on the CD.
Illustration: Graph: Time to Change (seconds)
Photograph: Pioneer's DRM-1804X can handle up to 18 CDs.
Fast Access to Multiple CDs
