The CD-ROM was developed from the audio CD shortly after its introduction.
The data on a CD-ROM is organized much like a magnetic disk. However, since a
CD-ROM cannot be written to, there is no need for a mechanism to track which
sectors belong to which file; the sectors of any particular file are sequential
on the disk and never change. Therefore, the CD-ROM has its own file system
called CDFS (Compact Disk File System).
Early CD-ROMs could hold 650 MiB of data or 74 minutes of media[1] (audio or video). Modern disks hold 700 MiB of data or
80 minutes of media. The disks could hold more bytes of media than other data
because media doesn't require error protection.
Early CD-ROMs were advertised as capable of holding the entire Encyclopedia
Britannica, including pictures on one disk.
A CD-ROM with an entire
paper encyclopedia which it holds
Green markers for CD edges
Some people believe that marking the edge of a CD with a green marker,
especially one made for this purpose, improves the sound quality of audio CDs.
If you believe this, please contact me as I can make you a great deal on shares
of the Brooklyn Bridge.
