Most locks are designed to be difficult/impossible to dismantle from the front when locked (for obvious reasons), but sometimes they are a lot easier to work on if you can remove the lock mechanism and get to all sides. I've done a bit with the tubular keys/locks used on the PC/AT cabinet, and on DEC machines, etc. Generally, you take off any cams/levers on the back (obvious nut) and take out the lock itself (slide-on clip, or another nut). On the IBM PC/AT one, there's a pin inserted from one side that holds it together. You have to drill this out (and you need at least a drill stand and prefereably a pillar drill or machine tool to do this). Then the back plate comes out of the housing and you can dismantle the lock. It consists of a disk with holes that rotates, and a set of pins, similar in concept to those in a Yale-type cylinder lock inserted in those holes. Once you've got it apart, you can do several things : 1) Reassemble it with no pins. Any key that will physically fit will turn it (even that DEC plastic key!). Who cares about security on a classic computer 2) Modify a key you have to suit the pins. You can mill the notches deeper in the key and re-arange the pins. Obviously you need to find a key where you can arrange the pins so that there are no notches that are too deep 3) Make up a set of pins to suit the key you have. You may even be able to buy the pins if you know a friendly locksmith (although in my experience such people are not keen to supply hackers with parts, even things like pins which couldn't possibly be used for breaking-and-entering). -tony