<Whether the distributed monitors and drivers are enough to run it <depends strongly on your application! Under an emulator - where If your developing with RT-11 for a specific task then sysgening is needed. If you need to run BASIC, DECUS-C, MicroPower Pascal, write assembly code files or edit text then the stock monitor are just fine. Sysgening to simply move to a different varient of PDP-11 cpu or disk however is not required. The typical example of sysgening RT-11 I've done was to use a console that wasn't DL (standard PDP-11 serial line unit) compatable. RT-11 was designed as both a development enviornment and a realtime executive for embedded applications. It's pretty flexible and small so it's good for lots of other stuff. It weakness (there is one) is that it does not use a scatter-gather map for storage so storage space can be poorly used due to device fragmentation. <I interpret "no source code" quite differently, mainly because I have <the source kits! Same here, V4, V5.0, V5.1, V5.4 I may even have 3.xx. Heck I've been running RT11 since '79 on one thing or another Q-bus. Allison