I have I V7 system Warren that runs on PDP-11 that was created from some of Keith Bostics's fileblock fragments. I can get this system up and running but the C compiler seems to be broke. I get ***error 8 which I don't know what that means but it's probably a pdp11 error code. I'm still trying to learn about the pdps but do you know how I might regenerate this C compiler from v7 that will fix c0? When I try to add floating point number emulation to the C compiler and regen things I always get an error at c0. How could I regenerate the c0 pass file? That seems to be the only thing that's stopping me from going further. I don't know if the compiler can be rebuilt from scratch if something like lib/c0 is broken. Bill