I guess this didn't get any upvotes due to the tame title. he literally got linux running on the drive.

"> All this was pretty useful information: it told me at least the Western Digital controllers seem to have an ARM-core that's accessible over the JTAG-port. It also told me these hard disks usually have a serial port, which is usually unused but could be useful for debugging my hack. With this, I should have enough information to start hacking. "