Which version of WOMBAT is on your WQESD? You can identify this by either looking at the sticker over the firmware EPROM, or if this doesn't tell you, by starting up the on-board diagnostics. Certain versions of Wombat do not interact well with RSX-11M's DU driver. Very often, older versions will work better than certain newer versions. Most of my systems are running WOMBAT V2.3, which works fine for me with the PDP-11 OS's (but *not* with later VMS versions.) WOMBAT V2.3 does work a little strangely with 2.11BSD's MSCP driver when you do a "shutdown -r", having something to do with the CPU doing a bus reset while the controller is still doing a write. I've never attempted to compile a list of which versions of the PDP-11 OS's do and do not work with various WOMBAT versions, but perhaps it would be worthwhile to build such a table. As it is, I just pop in different firmware EPROM's until it works. It's also worth checking that the WQESD really does respond to the CSR you think you've set it to. The table in your manual is probably correct for the most common address configuration PAL, but there are several dozen different address configuration PAL's that were made for special applications. If you have one of these non-standard PAL's, you'll probably be much better off to put the WQESD at 17772150 and the floppy controller at some other CSR. --- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology Voice: 301-767-5917 7328 Bradley Blvd Fax: 301-767-5927 Bethesda, MD, USA 20817