Mike Bell wrote:
Actually, it doesn't require a microscope. All current hard drives adjust the track location to compensate for expansion of the platter because the temperature has changed and other little details. What is required is a diagnostic controller that can adjust the head position just to the side of the track so it can read prior data. Some of what can be read in relatively short time is close to magical.
I'm not an expert, but I doubt whether "regular" SCSI (or FC) controller allow you to read track "neighbourhood" or - int other words - adjust head position. Nevermind. After you read this data you still have problem: what bits are set on because of previous recording, and what are because of latest recording, what because of pre-previous, etc. It is extremely hard to get any information from the string of bits, because of CRC (or other) coding, RAID-x implementation, emulation of CKD, EBCDIC translation, etc. Seems like 100000 elements puzzle with picture of dark night sky. All the bits are in the same colour <g>.
Disclaimer: Forgive me my poor English. -- Radoslaw Skorupka Lodz, Poland ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
