Exactly. Some Financial Accounting packages selling here in India back then used that trick. My former boss (in IT since 1983, from whom I got initiated to hac

Exactly. Some Financial Accounting packages selling here in India back then used that trick. My former boss (in IT since 1983, from whom I got initiated to hacking) wrote a disk copy program that would copy the source disk sector to sector, ignoring any error along the way, that dealt with the hole in short order. (He used it to make backup copies for legit users, and not for piracy.)