Data CD's

The CD format that we are going to call Data CD's is a modified offshoot of the original red book format which Philips and Sony called the yellow book format. The new format was intended to produce a standard data storage format but it soon proved to be so open ended that it began to produce many different incompatible  schemes. In the hope of rectifying this error a number of hardware and software manufacturers schedule another meeting at the the High Sierra Hotel and Casino in Lake Tahoe, Nevada. The new standard that resulted from that meeting was known as the High Sierra format until it was finally  adopted as the ISO 9660 standard.

There are two modes for Data CD storage. Under the first mode the scheme is essentially the same as the CD-A standard with 304 bytes per 2,352 byte blocks specified for error detecting and correction. Under Mode 2 there is no specified error blocks. Both modes are organized by a table of contents which is similar to a disk drive's file allocation table.

Obviously a computer program which cannot tolerate errors of any kind would require the Mode 1 standard where images or movies could. Although the later CD-ROM Extended Architecture, or CD-ROM XA adds the flexibility of mixing both modes but it hasn't become widely used because it requires special devices. As a result, most CD burning programs use Mode 1 by default. Be aware that the so called stretching of a standard CD is actually only saving as Mode 2. The perceived additional capacity is gained by eliminating the error checking and correction blocks.