11/93 Rebuild - SCSI HD now boots RT11

allison allisonportable at gmail.com
Fri May 31 13:40:47 CDT 2019

On 05/31/2019 02:04 PM, Rod Smallwood via cctalk wrote:
> Hi
>     Well I now have a bootable SCSI drive on my 11/93. Its not RSTS/E
> (yet) but it is RT 11 and reliable.
> Its a bit baseline but it runs.
> So next up was to see if we could get the RQDX3 to co-exist with the
> SCSI controller.
> I switched the base address to 160336 and it does not stop the SCSI
> drive booting as DU0.
> Had the RQDX3 been on the normal base address I think you would get the
> HD as DU0 and the two halves of an RX50 as the next two drives.
> But what happens to the RX50's when you move the RQDX3 to 160336 ?
> Rod
Under RT-11 you have to do a SET CSR and sometimes Vector when you move
a device off the default.  Its how I could have two DD (tu58) on teo
serial ports.  Same for RX02, RL02, with RQDX3 (with RD52 and RX33)
where the RQDX was set to a nonstandard address.

As I remember the CMD controller is nominally the same as RQDX3 for the
same address. so likely RQDX at the secondary address (see the manual)
will be treated well if not use the set utility.  It  only comes to mind
as I had two RQDX3s in one machine to make RD52 to RD52 copies at one
point.  Also my BA123 uVAX-II has both CMD SCSI controller (Rz56 x2) and
RQDX3 for RD52 wher the RD52 was the swap and page disk (QD540s are fast
but only 31mb) and by having independent channels helped with system

RSTS/E the conventions for non standard device addresses are different
but there is a mechanism for addressing that.  I've not used that.

Any of the PDP11 unix again there is a way but the process varies with
version and is unknown to me.  I tried once to get V^ to talk to more
than RL02.

In the end first make sure you using the suggested secondary controller
address.  Then use the OS dependent tools for installing additional drives.


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