Question on booting PDP-11/44

From: CLASSICCMP_at_trailing-edge.com <(CLASSICCMP_at_trailing-edge.com)>
Date: Fri Aug 6 13:07:07 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/hardware/
>>
>> 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_at_trailing-edge.com
 Trailing Edge Technology          WWW:   http://www.trailing-edge.com/
 7328 Bradley Blvd		   Voice: 301-767-5917
 Bethesda, MD, USA 20817           Fax:   301-767-5927
Received on Fri Aug 06 1999 - 13:07:07 BST

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