<> Is this a problem? Firstly, who says you'd use an MS-DOS format -- the <> CoCo uses 256 byte sectors for virtually everything, and I'd suggest <> keeping to that on the HD disks, just having more of them. As to being <> more wasteful, well, MS-DOS 360K (and 720K) disks fit 9 512byte sectors <> on a track, the CoCo fits 18 256byte sectors. Looks the same to me. My ampro and Kaypro run a 10x512 and 5x1024 format that yeilds 781k. If those sector sizes are awkward then bufer them for host deblocking. Doing that will also get you a mini-cache with a small perfomance increase.. Allison