Digital Rights Copy Protection and the C64
Mark Russinovich, author of Rootkit Revealer updated his Blog today with great piece about CD burning and disc emulation utilities using Rootkits to prevent the enforcement of copy restrictions.
“Because PC game CDs and DVDs do not need to be compatible with set-top players software vendors can store data on media in unorthodox ways that require software support to read it. Attempts to make a copy of such media without the aid of the software results in a scrambled version and the software has DRM measures to detect and foil unauthorized copying.”
I couldn’t help being reminded of my old Commodore 64/128 days. Being a curious kinda guy, I wondered how game publishers copy protected their software so I could make my own legal backups. :) Essentially, they used methods much like todays rootkits.
One common trick used was to write data on the floppy disc outside its normal formatted space. While the Commodore disk operating system consisted of 35 data tracks, game company's like Electronic Arts would store data on tracks 36–39. Their software would overwrite the normal Commodore DOS within the 1541/1571 disk drive so they could verify the floppy disk they distributed was in the drive.
It wasn’t long before some of the $300–$400 disk drives decided they didn’t like undocumented features and they locked up. The only solution was to take the drive apart and physically move the drive head back to a track zero position. If this could happen on a machine that only runs one program at a time, imagine the disasters possible on multitasking, multiprocessor, multi-language Windows system.