A Bit of Fun

21 March 2002

How to damage a disk drive through seeking:

  • Seeking faster than specified. While some drive motors simply “ignore” fast seeking - the motor only steps if the signal is held long enough. Others can be damaged. Some C64/Amiga programs actually do this!
  • Seeking towards higher tracks, over specified limits. Some drives implement mechanics that “hard stops” the head, just like track 0 (track 0 is always hard stopped). Others however may get misaligned by continuous attempts of over-seeking.

The chances of this is rather very remote (just like damaging your monitor through improper settings), but are possible - it all depends on the drive. This was kept in mind with the development of the dumping tool. When it checks track capability, it stops at the first sign of the drive not commencing with the seeking (it means it was hard stopped) and also automatically stops at cylinder 84 no matter what, so the drive doesn’t get misaligned accidentally.

Another thing is, if you dump cylinder 82 and 83 of a game, and the actual drive only supports reading up to 81, the last 2 tracks will of course be track 81 anyway (since the head is stopped there) and nothing else. There is no way after the actual dumping process to know if the last 2 tracks are genuine or not.

This explains why it is important to dump only within the limits of a drive, something that is done for you as a contributor.