EDIT: For a bit of background, though... I actually had to use factory diskettes, and write my alignment software around some very poor feedback the drive offered, and had to write it in MLX (machine language editor, by Compute's Gazette (wow my memory isn't that bad!) to get decent timing. Once you had a copy of my program, it was two screwdrivers and a lot of guts to break the lock-tite on the alignment screws. I like to hope I kept some people happy by not having to replace the entire drive.
After that protection came the pin-"poke" method of damaging a known sector of a disk. The protection relied on writing to that exact damaged area (factory disks used a laser, i used a pin), and expecting unreadable data. That took mad skillz. I wrote a few progs to redirect that to a place of known damaged area, and then had to write /parameter files to find and use that area. WOW, this takes me back.. such a cool time.
PS - Sorry about that darn Rambo game. I still (to this day) wonder what they did as a protection scheme past the 3rd level. That was downright good protection. (anyone?)
Until next time, here's a sound for you.. Veeeeerowww, dit,dit,dit,dit,dit... Veeeeeeeerowww, dit,dit, dit, dit, dit... (Quick, pull the disk, the drive is dive-bombing the stopper!)