The more-clever Atari copy protection involved the publishers using a customized drive to write two consecutive sectors with the same sector number. The loading program would request that sector twice in succession, so as the drive head finished reading the first one it would immediately read the second... which had different contents.
If you simply duplicated the disk, the drive would not read the sector twice and you'd be missing critical data.
There was a chip you could install in your Atari drive called the Happy Enhancement to defeat this.
I added this one to my 810. Screwed it up when I did it myself (note: 1st time ever soldering should not be done on your one and only disk drive) and got the folks at Happy to fix my botched job. The chip was really interesting: it basically gave extremely low level access to the drive to copy protected disks, but it was also leverged by their "Warp" disk operating system which was both faster than the Atari system and also was able to read wonky disks that the regular drives hiccuped on.
I still have my 800, Trak drive, and Commodore 1702. Mint condish. The 1702 needs to be re-capped, though, for sure. Last time I tried it, the shape of the picture was wonky.
The more-clever Atari copy protection involved the publishers using a customized drive to write two consecutive sectors with the same sector number. The loading program would request that sector twice in succession, so as the drive head finished reading the first one it would immediately read the second... which had different contents.
If you simply duplicated the disk, the drive would not read the sector twice and you'd be missing critical data.
There was a chip you could install in your Atari drive called the Happy Enhancement to defeat this.