I need some digital ports in my Opt 11 for my Octel 250. When I listed my unused digital units it printed every TN in slot 10 (10-0 thru 10-15). I thought it only printed unused units on a slot where at least one of the TNs was already being used. None of these are used, and they're all showing up. Does that mean they are in fact available? If I don't have mermail then I can use slot 10 for anything, right? thank you.