Correction
See tmz's post further down on how modern hdd firmware is partially stored on the platters. The hdd rom or eprom need then only hold a boot-loader to allow it to access the disk sectors where that literally disk operating system is held.
This poses a choice to anyone doing forensic investigation of a hdd. Either go the cheap route, ie power it up and clone it, then look at that, or the presumably much more expensive route of disassembling the drive in a clean room and cloning the platters on a mechanically similar / identical drive.
This may evoke bad memories in those lucky enough to have been responsible for Compaq desktops where bios firmware was stored on the hdd and programs for altering bios data had to be booted from floppy disk.
That saved a 50c eprom chip on each pc, and massively increased the suport costs of most of them.
Biting the hand that feeds IT
