Den 2025-11-11 kl. 11:14, skrev Johnny Billquist:
On 2025-11-11 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).