A total of 50 disks have now been captured. One disk would not read on the Amiga but a bit of isopropanol and a cotton bud soon sorted that problem. I appear to be having trouble with 2 of them, very old disks (Workbench 1.3.2 and The Very First).
I also initially had trouble with a “Fonts 2.04” disk but a re-scan sorted that problem. Which made me wonder again. I still reckon AmigaDOS has some kind of retry algorithm, as I have found the next track read might be OK. I have started looking at XCopyPro once again as it does everything in raw MFM mode and sure enough it was interesting to watch. (By the way all 3 of these disks has the nasty clicking sound of dirt on the surface…).
The CHECKDISK function on these 3 (2 now) problem disks I have shows a red number on a track but after another spin it turns to a green zero. So this shows even the miggy has trouble reading some sectors. The 2 troublesome sectors though seem to read first time on the Amiga, although in general these 2 disks have a number of sectors XCopy needs to scan more than once.
I think the next steps are to look closely at these 2 problem sectors as I have done with al the others. Total 48/50 have matching MD5 hash.