To clarify a bit ... Don's disks work perfectly with the DD controller ... and with the N* base system itself (post overhaul). However, when I swap out the controller for an SD iteration (tried two actually) ... no joy. While the boot drive does indeed enable, I can hear that no sectors are actually getting read. I'm not positive, but I believe that the N* software (both DOS and CP/M) changed quite a bit with the advent of the DD controller, as did the firmware bootstrap. And while the DD controller can read and format SD disks ...I don't think that it can create bootable disks that work with the older SD controllers. Haven't tried it myself yet ... Scott