PDP-11/84 Qbus slots for memory

[Paul Anderson]

Would a Quniverter would work?

On Sun, Jul 22, 2018 at 4:01 PM, Charles Dickman via cctalk <
cctalk at classiccmp.org> wrote:

> On Sun, Jul 22, 2018 at 8:47 AM, Mark Matlock via cctech
> <cctech at classiccmp.org> wrote:
> >    Now my question is, there are 3 Bus slots in the 11/84 above the
> Unibus map board, would it be possible
> > to put a dual width Q22 I/O board in the second memory slot (not the PMI
> side of the slot) and have it
> > able to DMA into the MSV11-JE?
>
> The answer I have heard here over and over is that an 11/84 with the
> UNIBUS adapter and PMI memory does not have a Qbus. As I understand
> it, the KDJ11-B (M8190) bus protocols change when a KTJ11 (UNIBUS
> adapter) is present and so what would be expected to be Qbus isn't.
>
> Others can probably explain the details and I think there was a DEC
> Micronote that explained the protocol modifications involved.
>
> > Mark
>
> -chuck
>