RL02 version of UNIX6?

Absolutely. Oooh, good point - I hadn't thought of that. I couldn't quickly find a 'minimum memory required' in the release notes for V6; the 'Unix Summary' says it needs "48K to 124K words". I think that might be a bit excessive; I seem to recall our -11/40 had, to start with, only 48KB. Anyway, try it, and let us know what happens. How much memory does the system have on it now? If it doesn't work, I can do some experiments and see what's the least amount of memory one needs. There are a whole bunch of parameters which will reduce the size of the resident OS; if necessary, I can turn them all down to the minimum, and see what we get - although just reducing the number of disk buffer may do it. As for the applications, it does swap, so there's no requirement for more than one process to be resident at a time, so whatever the largest is - probably the C compiler - there only needs to be enough memory left over after the OS is loaded, for that one. It looks like the shell is about 10KB, for example. If it won't boot, don't trash the disk: if we send you another bootable disk, we can make it tiny (only Unix, and enough files to get it running: /etc/init, /bin/sh, etc), and if/once it books, you can mount the disk you just wrote and move the bootable Unix system image over, and then reboot on the current disk, to get to the rest of the stuff. Do you have two working RL drives on the machine? Noel