11/93 Rebuild - SCSI HD now boots RT11

Jerry Weiss jsw at ieee.org
Fri May 31 14:09:15 CDT 2019

On 5/31/19 1:04 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

In RT11 the mapping of the controllers (port), drives (unit) and 
partitions is stored in the device handler of the disk you bootstrap 
from.  You can have customize different configurations on each of your 
SCSI drives and the RQDX3 HD.  You have to make sure that the disk being 
booted has a valid mapping for the SY disk on its handler (DU.SYS or 
DUX.SYS).  There are no checks on the "SET DU" commands to ensure the 
resulting configuration is bootable.

Check out the RT-11 Device Handlers Manual  (section 2.3 in the Aug91 


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