[pups] booting RT11 from alternate controller

Jonathan Engdahl j.r.engdahl at adelphia.net
Wed Apr 2 23:14:00 AEST 2003

I'll have to try this with the RQDX3 as primary and the SCSI as secondary.
Maybe BSD is smart enough to do it right. In any case, I have the source for
the BSD boot code, and I can fix it. It will be a pain, though, having to
type the alternate address every time I boot BSD. I'd probably have to
restructure /dev and /etc/fstab also, and who knows what else. Maybe it
would be easier to change the jumpers if I needed to run RT11. I don't use
RT11 that much, but I'd like to have it available.

Jonathan Engdahl

"The things which are seen are temporary,
 but the things which are not seen are eternal."  II Cor. 4:18

----- Original Message -----
From: "Fred N. van Kempen" <Fred.van.Kempen at microwalt.nl>
To: "Jonathan Engdahl" <j.r.engdahl at adelphia.net>
Sent: Wednesday, April 02, 2003 5:58 AM
Subject: RE: [pups] booting RT11 from alternate controller


> I have a PDP-11/53 with a SCSI controller at 172150, and an
> RQDX3 at 172144.
This works for the ROM, but most PDP-11 operating systems will
refuse to boot from anything but the "default" controller of
any kind, meaning, an MSCP controller it will only accept at
172150.  The OS itself can deal with them, but not so for the
boot-level code that loads them.

I have tried similar setups with an 11/83 using an ESDI disk
controller at MSCP #0 (doing KDA50 emu), and an RQDX3 at
MSCP #1 (just for the floppies, indeed) and that didnt work
either, with RT11, MicroRSX and Ultrix.


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