Den 2025年11月11日 kl. 11:14, skrev Johnny Billquist:
On 2025年11月11日 06:00, Mouse wrote:
That may not be the relevant thing, though. I don't know 1.6.1 in
enough detail, but perhaps kernel output is polled but userland is
interrupt-driven? Maybe something is wrong with TXCS-driven
interrupts?
That would be the case, yes. Unless I remember wrong.
Since output from the kernel works, we can at least say that there is
nothing wrong with the serial port as such. And the booting process
went fine.
And VMS also hangs after printing a banner... Which would suggest that
there is something funny either with the printing on the console, but
which is interrupt related, or something else is getting the machine
stuck at an elevated privilege mode, preventing interrupts from being
processed.
I would actually probably suspect something else isn't completing, and
the processor is stuck at some elevated prio. The console is probably
working just fine, including when interrupt driven. But something else
is not.
I assume we're talking about a real machine here. So it has actual
Unibus. Simple suggestions would be to remove everything not
absolutely required to get the machine running, and really make sure
you have bus grants in all Unibus slots not having a card in it. Also,
make sure the NPR jumper is in place. This one can be a bit tricky,
since it's actually a wire on the back side of the backplane, which
might have been cut. There a double height bus grant cards that also
covers the NPR signal, but the small square ones do not.
And if the Unibus isn't properly configured, you can probably get
things hung/stuck for some time.
It's a 780, Unibus is not involved here at all :-)
The PDP11 is connected directly to the backplane (SBI).