"It depends". RT-11 is pretty versatile, and not awfully picky about being booted on a particular type of processor. (With the exception, oh, of trying to boot RT11XM on a 11/03...!) RSX-11M and M+ will complain if a peripheral specified in the SYSGEN isn't there in the boot process, but generally the base OS will come up all the way. RSTS/E can be very picky about what hardware it'll work on, but as long as you stick to the autoconfigure rules you're OK. Many of the PDP-11 Unices can be quite particular, especially if you're booting a non-Generic kernel. All of the above *can* be made to break on anything except a particular hardware configuration, but generally this takes a bit more effort. One thing you'll have to realize is that your current hard drive controller is emulating a RL02, and you won't be able to use it along with a "real" RL02 unless you do a SYSGEN or otherwise (there are some shortcuts) put a second DL:-type driver into the system. You'll also have to set one piece of hardware and one of the drivers to different CSR's and vectors. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927