Correct, starting with RSTS/E V9.3 (DECnet/E 4.0). Older versions (V7.0 and up) are Phase III. RT-11 is Phase III as far as I know. Ah, that's what I was remembering. When I had set up a RSTS system some time back, it was a V7 system and that's what was Phase III in my memory. My current RSTS system is indeed Phase IV. --Marc