ATIP stands for "Absolute Time In Pre-
groove" and is part of the
Orange Book CD specification. The ATIP is a physical area on every
CD-R and
CD-RW in which the following information is written at the factory:
- Suggested capacity of the disc
- Manufacturer of the disc
- Type of disc (audio only, etc.)
- Suggested writing speeds
- Absolute lead-in time
- Suggested final address where data can be written
- Motor control data for the CD-R/W drive's servos
- A carrier frequency of 22.05 kHz used by the drive to determine time code information
Some of this information is quite critical to the drive's ability to burn the disc -- allowing it to establish exactly where the head is located. Other things in the ATIP no longer need to be taken too seriously as quality modern CD-R/W drives could probably disregard the stuff marked as "suggested" if they had to. In the past this information may have been important as a drive might otherwise damage itself by attempting to write beyond its physical limits.
The most interesting part of ATIP for the average person is the manufacturer info. This can give you insight into the quality of the disc when referenced against one of the web sites that gather data on that sort of thing. The ATIP manufacturer info is also used in some copy protection schemes. Since ATIP data can only be read by burners though it is easily defeated by using the disc in an ordinary CD-ROM drive. Alternately (if using Windows) you can right-click on the CloneCD tray icon and check the "Hide CD-R Media" menu item.
As with anything that defeats copy protection I never do it because doing it is a violation of the DMCA and would most likely cause me to be dragged away in chains.