At MIT, the PWB1 (effectively) system that was standard at Tech Sq had had its teletype driver completely re-written by the time I started using it, and that was changed, so I never saw this IRL. Recently, I needed a Unix to run under Ersatz-11, to talk to physical QBUS -11's and download them over their console line, so I went with V6 (since I had not at that point managed to recover the MIT system). Wow. Talk about a rude awakening! That was one of the things that was, ah, problematic - and in V6, there's no way to change the interrupt character. (And no, I didn't feel like switching to a later version!) An even bigger problem was that in vanilla V6, there's _no way_ to do 8-bit input _and_ output. Sheesh. I managed to fix that too, after a certain amount of pain. (I missed a code path, or something like that, and it took me quite a while to figure out why my fixes didn't work.) Noel