(We're considering whether or not to employ truecrypt or bitlocker over the machines or not, 'til then we're using HDD's passwords.)
The HDD is really not encrypted at all, we just want to make it a bit safer, not NSA-proof. The HDD password is kept on disk, but unaccessible for ordinary users, if the password was kept on the HDD controller (the disk-side part of it) a simple HDD controller switcheroo would solve the problem. You're wrong in many ways, the ATA specification do have a specific command for that since ages ago.
