You know, it's really hard debuggin a machine when you're not told all the symptoms :-) More seriously, this does sound like the standard Micropolis 1300-series problem, when that rubber bumper goes sticky and prevents head movelemt. The bad news is that all Micropolis 1300s (and their ESDI equivalent?) suffer from it, or at least if they don't they will soon. Finding a replacement 1300-seires is probably not the wisest thing to do, therefore. I've never tried it, but I have heard that people have had some success in openign up the HDA *yes, outside a clean room), removing the bumper, shutting the whole thing up and using the drive as normal. How long it'll keep working is anohter matter. I beleive the hard disk must og 'Ready' Quite what that means I will have to check -- the boot ROMs check for a particular state in one bit of a particluar port. I candig out the EIO and DIB schematics to find out just waht that means if you like. Any reason not tu use some other ST412-interfaced drive? The PERQ _can_ use it. -tony