11 Feb
2015
11 Feb
'15
9:32 p.m.
OK, I recompiled again with PDP11 = 34. and UNIBUS_MAP = 0.
I set simh to 11/34 and I managed to get actual panics before (that I
didn't record), but now I'm just getting hangs, mostly when hitting ctrl-D
to bring system to mutiuser. Same if I mount -a in single user and then
try to access /usr (works for a while, then hangs.).
When hung, I can still get character echo to my terminal but can't
interrupt or background the running command, etc. Would it help if I
traced memory and single-stepped through the (apparently) infinite loop?
The real 11/34 runs like a top under regular 2.9 (on rl02). Can't get it
to do anything wrong; no panics, no hangs.
However, here are some examples of crashes on the real pdp11/34 (booting
via vtserver, then bringing in system from the MSCP disk), with the
original 2.9bsd-MSCP kernel (the one specifically built for 11/23):
Opened boot.dd read-write
rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr EOF
40Boot
: ra(0,0)unix
Berkeley UNIX (Rev. 2.9.25) Sat Aug 11 17:56:41 EDT 2001
mem = 158720
CONFIGURE SYSTEM:
ka6 = 2200
aps = 141572
pc = 50456 ps = 30250
__ovno = 7
trap type 11
panic: trap
and another: plain boring old hang at boot when trying to size devices.
Can't even echo characters this time.
Opened boot.dd read-write
rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr EOF
40Boot
: ra(0,0)unix
Berkeley UNIX (Rev. 2.9.25) Sat Aug 11 17:56:41 EDT 2001
mem = 158720
CONFIGURE SYSTEM:
One thing I think is interesting is that it's claiming 158720KW of memory.
Is that weird? The real 11/34 has 128KW and simh is set to 256. Where's
it getting that odd number? Vanilla 2.9.1 on the real 11/34 boots with
Berkeley UNIX (Rev. 2.9.1) Sun Nov 20 14:55:50 PST 1983
mem = 135872
On Wed, Feb 11, 2015 at 11:20 AM, Noel Chiappa <jnc(a)mercury.lcs.mit.edu>
wrote:
From: Jacob
Ritorto
I think it's something to do with the fact
that he compiled it to
run on
an 11/23. Maybe it lacks unibus support.
No, the UNIBUS and QBUS appear (from the programming level) to be
identical.
There are subtle differences (the /23 and its devices can address more than
256KB of memory, and some devices have minor differences between the QBUS
and
UBIBUS - e.g. the QBUS DZ has only 4 lines, not 8), but in general, they
should be interchangeable.
Maybe something to do with clock differences.
Again, if it boots at all, that's not it. (The vanilla /23 doesn't have a
software-controllable clock, and when booting Unix on one, one has to leave
the clock switched off till UNIX is running - at least, for the early
versions
of UNIX.)
I fired 2.9MSCP up in simh emulating an 11/23 and
it works fine.
Just to
corroborate my hardware experience of it on the
'34, I switch the cpu
emulation to 11/34 and got a mostly identical crash sequence as with
my
real hardware.
Ah. Now we're getting somewhere! If the simulator crashes in the same way,
it's
not flaky hardware (my first guess as to the cause).
What are the symptoms (in as much detail as you can give us)? What, if
anything,
is printed before it dies?
I changed ...
UNIBUS_MAP = 0
to
UNIBUS_MAP = 1
The /34 doesn't have a UNIBUS map.
Noel
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