Norsk Data notes
The ND bootloader is called OPCOM. When you turn on the machine you're presented with a '#' prompt on the terminal, this is the OPCOM prompt. The next steps usually are:
'MACL' (MAster Clear and Load) reloads microcode, resets CPU and bus, you apparently should always do this before anything else. When it's done it prints an extra prompt so you have two prompts, and the '&' means to load the default boot device (decided by the "ALD (Automatic Load Descriptor) switch").
There are other interesting incantations in the OPCOM, more on that later.
SINTRAN boot process
I've been trying to get a grip on the boot process (seems like a natural place to start), so far the extent of my discoveries is that the files HENT-MODE and LOAD-MODE are the equivalents of rc scripts, where the former is loaded from a "cold start" and the latter I think for both a cold and warm start, but the distinction isn't all clear to me yet. There's loads of overlap in the two files on my system, and I'm pretty sure both are executed on a cold start, which seems odd.
There doesn't seem to exist an automated way to do clean shutdowns, so it's basically a long list of tasks to do manually -- more on that later.
SINTRAN manual boot
Instead of running '&' at the OPCOM, which begins the automatic boot process and runs the HENT-MODE and/or LOAD-MODE files that mount disks and start up all the services etc, I think I can somehow do a manual boot (kind of like Unix single-user boot). This I feel is worth a try, to get a feel for the process. This procedure may be what ND calls a "cold start", but I don't know. They use "cold start" and "warm start" all the time, yet I can't quite get a feel for what the difference is supposed to be.
Maybe it was the wrong incantation. It didn't seem to do anything on mine. Wait, yes it did. It fucked my OPCOM up (the ALD switch I presume). Now '&' doesn't work. Maybe '20500&' will fix it, as that should be booting from the first disk (but possibly only if it's of a specific type?)
My ND has two Ethernet cards, I believe it's one 'Ethernet II' module and one 'Ethernet III' module, but I've yet to find out which is which physically. TCP/IP is supported, and this support might be called OpenLAN, underneath or alongside which exists ND's own networking protocols and tools which are called COSMOS.