09-12-2018, 01:59 PM
It's NOT the drives! FLUX itself is a variable bit rate! Every single bitcell is a slightly different time period and that can vary from <1us to over 15us, depending on the disk format. Mac disks have 4 "speed zones" with fixed width bitcells.
It's more likely that your disk drive's heads are dirty. You are going to find that you will probably need to be cleaning the disk drive heads just about every disk you intend to archive. The oxide is just literally falling off because of time, and 3.5" disks are far worse than 5.25" disks.
The number of revolutions after 2 revs doesn't matter. Because only 2 revolutions are actually used - the last 2 in the case where you have selected more than 2. You only need 2 full revolutions to make sure that 100% of the entire track is captured.
I would try cleaning your drive heads and trying it again.
It's more likely that your disk drive's heads are dirty. You are going to find that you will probably need to be cleaning the disk drive heads just about every disk you intend to archive. The oxide is just literally falling off because of time, and 3.5" disks are far worse than 5.25" disks.
The number of revolutions after 2 revs doesn't matter. Because only 2 revolutions are actually used - the last 2 in the case where you have selected more than 2. You only need 2 full revolutions to make sure that 100% of the entire track is captured.
I would try cleaning your drive heads and trying it again.