Question on booting PDP-11/44 - test-drb@ccmp.vtda.org

6 Aug 1999

...
   >Am I
correct in assuming that when a PDP-11/44 finds that it has more than
 >one controller in it that it can boot off of, that it drops you into the
 >monitor, so  you can select the device you wish to boot from?  
> I think that you're asking "Does the 11/44 have a sniffer boot?"  The
> answer to that is no.  The boot device (or "boot to console") is
> selected by DIP switches near the actual physical boot ROM's
> on the M7098.  See
> 
>   http://metalab.unc.edu/pub/academic/computer-science/history/pdp-11/hardwar…
> 
> specifically, the file "1144.boot.roms", for very detailed information
> on identifying the boot ROM's present and how to set the DIP switches
> to select the appropriate one. 
...
 Good job of interpreting a question when I wasn't
even to sure what I was
asking. 
You ought to see what some of my customers come to me asking :-).

...
   The worst part is I knew about those switches, but
had forgotten
about them.  Somewhere I've got written down which boot ROMs it has
installed, I know for a fact it's able to boot DL:, it has the ROMs
for DU:, and I believe it also supports TU58 and RX02, but might be wrong on
one of the last to. 
The URL I mention above lists all the DEC part numbers for the boot
ROM's, so if you can read them off you'll figure out which ROM's you
have.

...
 So the next question would be do I have to go in and
change the switch
settings on the board in order to boot something other than DL:? 
To *auto* boot something other than DL:, yes, you'll have to change
the switch settings.  From the console (">>>") prompt, you can boot
any device that you have boot ROM's for (or key in the bootstrap
for any device.)

...
 Wait a minute, I see a problem here.  Since the boot
device is based on
switch settings, even with controllers for other devices that it can boot,
it shouldn't be dropping me to ODT should it?  With just the RL controller
in the system it boots off one of the packs without skipping a beat. 
What did you change in the system that caused it to go from "auto boot
to DL:" to its current behavior?  A break in backplane continuity can
make it look like the RL11 isn't present in the system, and that'll
drop you out to the console prompt.

-- 
 Tim Shoppa                        Email: shoppa(a)trailing-edge.com
 Trailing Edge Technology          WWW:   http://www.trailing-edge.com/
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