<KL11 setup: addr: 777560 , vector: 60. That is a majik address. 176560(16bit address) and vector 60 is the default console for any KL/DL or similar device. It is insensitive to what the device generally is but the basic status and registers must be there. RT-11, XXDP and friends expect it unless the particular copy was built for an odd address, then console ODT (for those that have it) will not be available and the console cannot control booting. Not a good idea to do that by the way and you can only do it on the non-microODT processors. Also RT-11 (any version I have played with) MUST have 8kw of memory, again you can custom build for smaller but for limited application only. The smallest almost OS was the IOX package (IO Executive) for embedded apps, the Micropower pascal system could build for small memories. Allison