Now that I have my PDP 11/40 running with twin RL02's I have been having fun with it by using simH to make disks and then porting them to an actual disk using PDPGUI program. Here's a good example, if you're looking to run RSX11/M on a PDP 11, I worked through a way to get it onto an RL02 drive. Version 3.2 will run on any PDP 11 with 64K, even 11/20. http://vintagecomputer.net/browse_thread.cfm?id=668 I skimmed the web for a week, plus got some ideas and suggestions from simH users. The hard part was to find a way to get an operating system only found on RL01 drives to an actual RL02 drive. Most people believe RSX11/M is better than RT-11 I don't know yet, I was more interested in the process of making disks using simH. There is a lot of potential to do disk and tape operations with simH that would be impractical with actual hardware as very few of us have the real things. I would love to run UNIX 6, but I have a bad extended instruction set card (EIS M7238) so I have to wait for that to get fixed before I can run UNIX :-( Bill