I don't know much about the other versions, but it would all depend on what's in the bootstrap (usually contained in block 0 of drive 0, at least on older 11's). In V6, the bootstrap in block 0 prompts for a file name, and when that is entered, it loads that file into memory and starts it. (It doesn't have to be in the root directory, IIRC - I'm pretty sure the bootstrap will accept full path names.) How did you create a V1 filesystem? (I don't know, BTW, what they look like - is that documented anywhere?) It's probably not the same layout as the V6 (which I think is the same as V5). Noel