There were 3rd party Unibus to Qbus converters that would handle the signal Mux/decus issues on the bus lines.
I never saw any on 11/780 class boxes. Crappy UBA was slow. Most were used to put Unibus peripherals on Qbus Vaxes. Bill -----Original Message----- From: Clem Cole <cl...@ccc.com> To: William Pechter <pech...@gmail.com> Sent: Thu, 09 Mar 2017 15:19 Subject: Re: [Simh] Simh Digest, Vol 158, Issue 14 On Thu, Mar 9, 2017 at 2:54 PM, William Pechter <pech...@gmail.com> wrote: > There was no DH11 driver until the DHV Qbus... And who knows what that was > compared yo real DH11. Let me try to decode that time line and the implications ... 1. VMS does not officially support the DH11/DM11 combination (ever)... (because of your earlier comment about officially not supporting full Unibus DH/DM backplane on the UBA - which makes sense. 2. As Al points out there were DECUS drivers in the wild for them. 3. At least one of the 3rd party vendors does develop a DH11/DM11 compatible board which becomes native for UNIX (BTW - we should check the Ultrix SPD - I wonder what Ultrix says about -- I bet Ultrix recognizes it, but its not in the SPD). 4. Through the days of the UBA based Vaxen with a full PDP-11 style unibus, customers (like me) used either real DH11s with afterwork DH clone or in an unsupported bus situation for UNIX as a minimum. By point 2, we can assume the VMS customer are doing the same thing, but we don't have anyone that "did it." 5. Time goes forward, DEC develops the DHV Qbus board. 6. Was there a Vax based system that had a UBA that spoke QBUS? I don't remember such a beast in ZK in the Ultrix lab, and we did not have one in pile of gear we at LCC in those days. 7. Assuming 6 is yes, does that mean VMS supported the DHV on same? Again - I do not know. William do you agree from the HW standard point... I can verify the UNIX side of things, but 10 years development from 1980-'90 I just was not close to the Vax as I was doing other things. I got back in early 90's when LCC took over Ultrix development and Vax support came with the contract; but I admit I did not as much atten as I had in the 70s, Clem _______________________________________________ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh