korfhage%ucla-ats@sri-unix.UUCP (10/25/83)
From: Willard Korfhage <korfhage@ucla-ats> I have read that this copy protection method involves recording some marginal data in places around the disk. When reading such areas on the original disk. you expect to find random data in that area. If you copy the disk, though, the drive will use good, strong pulses to record good, not marginal, data. I am not sure what prevents you from recording random data in the places that the copy protection program looks. Perhaps the marginal data is likely to change with each read whereas properly recorded data will not.