Close, but not quite
So, it looks like I'm getting closer. I read the disks with the 'physical' read option, which did sector skewing. Now that I've looked at them, I think that was a mistake. It looks like they are meant to be read in a logical mode, so I'm redoing a few to analyze again.
So I wrote a program to try to sort that out. It did work, but not quite. It got things almost right, but over-shot the mark when it came to getting the second or third file from the tar ball. It looked for all the world like there were missing sectors or something.
On a lark, I decided to try to read 11 sectors instead of 10 that RX-50's are usually formatted at. And I was able to read all 11, and the data for the 11th doesn't seem to match anything else. But we still have a mismatch, and I'm trying to chase that down. Well, 11th sector for tracks 2 and larger. So, I need to try to figure out why I'm not seeing extra data between the files.
So it looks like I'll have to do this again to get all the bits.... I think I need to puzzle this out with some friendly files that have text (include files) in them. maybe there's 12 sectors, though that would be unprecedented for these drives. You can do 800k like the RX-50, and also 880k for the amiga, but I don't think you could fit much more than that on a track, but who knows, maybe there is 12 sectors and I'm messing up.
Then again maybe I should just wait for the Kryoflux to show up so I can image the entire disk, including the boot disk.