OT: paging MAC expert(s) --- What's a Performa?

It's the "quite a bit of extra work" that concerns me, as the boys at M$ haven't managed to do it right yet, and they've been at it to the tune of 100K man hours per year for a decade or so. Recording a bitwise image of what you receive from the disk may or may not give you all the information you need to recreate the files, since you may or may not know how the OS deals with them. What's more, in order to make a complete record of the drive, you have to record every bit it has on it and save them as a single unit, since you don't know what the drive does with the data you send it. That's the same reason, BTW, why the drive to which you write such an image must be an EXACT duplicate of the one from which the image was recorded. The second drive may otherwise claim to be identical but have a different number of sectors per physical track, use different mapping arrangements, etc, and, especially, have different bad blocks. Since you're going to send data that goes to where the drive sends it and not necessarily to the same physical location from which you got it because the drive may use different modulation, servo coding, etc, and therefore may have a different number of sectors per track in the region of the drive to which the data is sent, you may be disappointed with the results because IDE drives hide too many details from the end-user. Depending on the level of the interface you use, you may not be able to use image recording at all. Further, if you don't know absolutely for certain, what the drive does with the data you send it, and what the OS does to process data to and from the drive, you're on thin ice. I'd not recommend using image recording with a later generation IDE drive at all. Since SCSI is well established as to how it operates its data management, it yields more hope that you can process an image, though the vagaries of the OS are still a limiting factor. Image recording should work fine with MFM- and RLL-encoded drives, even on a track-by-track basis, and those offer some hope that one could substitute one sort of drive for another but hte ones which use BOTH CHS and LBA addressing won't tolerate the sort of operations to which an incrementally developed OS like Windows could create. Dick ----- Original Message ----- From: "Christopher Smith" <csmith(a)amdocs.com> To: <classiccmp(a)classiccmp.org> Sent: Tuesday, November 20, 2001 10:07 AM Subject: RE: OT: paging MAC expert(s) --- What's a Performa?