Appendix

Session-at-Once (SAO)

As a writing method that combines the advantages of the above-mentioned “Disc- at-Once” and “Track-at-Once,” you can combine multiple tracks into one session and write them, and then add additional data.

For example, this is the writing method used to create a CD EXTRA format CD. The music tracks will be recorded in the first session, and the data will be recorded in the second session.

Example: CD EXTRA

0

Audio

Audio

Audio

Data

Track 1

Track 2

Track 3

 

 

 

 

 

 

Session 1

Track 4

Session 2

Lead-in

Lead-out

Lead-out

 

/Lead-in

 

Packet Writing

This mode is used when writing to a track of a disc using small blocks of data called “packets,” in a manner similar to a floppy disk. This mode is useful when making small incremental backups of data. You will need to use software that specifically supports packet writing, such as Adaptec’s Direct CD.

1

2

3

4

5

6

7

8

.

.

.

.

.

.

.

.

.

.

.

.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Packet

Same as writing to floppy or hard disk

nDiscs must be formatted before they can be used for packet writing. With CD-RW, erased data can be overwritten until the disc is completely full.

With CD-R, the space used by the erased data cannot be reused and is “masked” so that it is no longer visible. This can be done up to 100 times.

30