On 2013-01-06 21:28, John Wilson wrote: From: Johnny Billquist <bqt at softjar.se> You must be talking of the PDT-11/150 then. The /110 and /130 sat inside a VT100 shell. Extremely similar to a VT103 (I actually never figured out what the difference between a VT103 and a PDT-11/130 is.) I may be grossly misinformed, but my understanding is that although the /110 and /130 both live inside a VT100, they're *not* like VT103s, and have no Q-bus but use a custom CPU board just like the /150 (I doubt it's the exact same board, but a similar design). I could have sworn the 110/130 manual on bitsavers (which is misfiled away from the 150 manual -- I forget where) said so but on a quick skim I can't find it. The I/O hardware has enough programming differences that it can't be regular Q-bus stuff, although I suppose they could have made a whole set of PDT-specific boards. You know, I had never even thought that thought, but now that you mention it, it makes total sense. I think you must be right. All the PDT-11 use the same system board. It's not a Qbus at all, in any of them. That definitely also makes it very different from the VT103. Thanks for making me understand this. :-) Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt at softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol