> So ...If the DHV is supposed to the simh emulation of the combination of a > DEC DH11 and DM11 pair (the DM11 was the modem control option for the DH), > then this should "just work"
The SIMH VH device is a simulation of the DEC DHQ device (M3107), a dual height Qbus board, normally supporting 8 lines and features DHU/DHV "compatibility." DHV was an earlier quad height incarnation, while the DHU was a 16-line Unibus interface. These are all similar to the historic DH/DM combination but not identical. It's been too long since I looked at the DH/DM combination but if I recall correctly the actual programming was a bit different from the DHQ, though the general idea was the same, similar to the Able device. I have no experience with 4.3BSD-Quasijarus, so I couldn't say with any authority whether or not it would support the DHQ, but as Mark indicated, it would need to be set as a DHU for Unibus and 4.3 would likely need to recognize the difference(s) between DHU and DH/DM. Also agree with Clem's comment about DZ: a DZ could easily bring a 780 to its knees with per character interrupts. The Able board was historically the first out of the gate, IIRC, to support reasonable serial performance in the VAX arena. John _______________________________________________ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
