I hadn't thought to check in the System Profiler or Disk Utility, but the CyBook did show up there if booted while plugged into the USB.
A reformat of the internal partition and a restore from a recent backup (just by drag&drop) fixed things.
Thank you both very much.
Originally Posted by cbell
I accidentally deleted the system folder (and its contents) in the visible partition of my Cybook. I saw diagonal squares, checkerboard pattern, exactly the same as yours, when I disconnected the Cybook from my PC.
I had a back up on my PC and I copied the system folder back to my Cybook.
If you can access your Cybook via USB connection to your PC, you can check if the system folder is still there...