Click a Nerd


The firmware in the majority of drives consists of a series of modules: P-list, G-list, SMART Attibutes and U-List (Firmware Zone Translator). Each of these performs a key function. An example function is defect control, no disk is manufactured without flaws and there will be some sectors on the drive that cannot be used. At the time of production these flaws are recorded in the disk firmware as the 'P' (permanent / primary / production) list. As the disk ages and through wear and tear other sectors mail fail; this is recorded in the 'G' (growth) list. Reads and writes are automatically redirected (remapped) to spare sectors, see Figure below.

At Click a Nerd we are constantly tasked to recover data from a failed hard drive. At times this process involves the moving of a firmware component from the original hard drive controller board (bios chip) to a donor controller board. This is intricate soldering and technical work.

For more on data recovery from defective hard drives that are not mechanically failed but improper ID or BIOS mapping, please contact us.