Reply 20 of 41, by firage
Audio tracks don't figure into the copy protection part; I meant to say they present the only challenge in backing up DOS era discs instead of any DRM methods. DOS games look for a file on the disc or check the label and that's it, well in the domain of the basic ISO format. For CD audio support, you need an alternative image format. With real protections later on, ISO is out also for its lack of raw/subchannel data support.
It's good to check for matching CRC from multiple reads, because there's very little error detection in the audio ripping process otherwise. When audio glitches happen, only the most severe sync errors pop up a notification. Discs in clean condition do read glitch free 99%+ of the time, with properly working software and hardware.