[HECnet] DU11 vs. DUV11

[Lee Gleason]

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.

Yes, I think that's the case. I found a paragraph in the PDT 11/130 manual that states that the PDT family all have "bounded bus" systems that are completely buried in the PDT card, and an 8 bit processor actually talks to the IO devices. It also says that a word transfer to the IO system takes 90 microseconds, and a byte transfer takes 180 seconds, so that explains the logic behind the optimization.

I never thought of any of them running any type of RSX - I   ll have to dust off one of my PDT-11/150s and see if I can get some sort o' RSX on it.
--
Lee K. Gleason N5ZMR
Control-G Consultants
lee.gleason at comcast.net