I actually do file system checks on v5 as it's the early unix I use the most: check -l /dev/rk0 check -u /dev/rk0 same for rk1, rk2. The v5 manual entry for check references the 'restor' command, although the man page for that is missing. Your idea of starting up in single user mode is a good one although I'm not sure if it's necessary to check the file system on each boot up. I've been running this disk image of v5 for about two years and no blow-ups as yet. I also keep various snapshots of v5, v6 and v7 disk images for safety reasons. And there are text files of all the source code changes I've made, so if disaster strikes I can redo it all. Mark