From: John Welch
CLR
765000
LAD
EXAM
'Bus Err' light comes on.
Oooh, that's very interesting, and illuminative. The ROM isn't working (so
there's no way for the software console to work - its code is in that ROM).
So look at Section 1.5 of the Technical Manual
http://bitsavers.org/pdf/dec/unibus/M9312_TechRef.pdf
and make sure all the jumpers on the M9312 are as required. In particular,
jumper W-8 should be _out_.
If it's not, that would explain why the ROM at 765000 isn't resonding. If
it's
in, that M9312 board probably has a problem.
Also, while we're at it, it's probably worth making sure the CPU will
run. Do this:
CLR
LAD
777 (This is a 'branch .' instruction)
DEP
EXAM (Should display '777')
CLR (I think you can dispense with these
LAD two, but just to be safe...)
CTRL-START
'Run' light should come on
CTRL-HALT
'Run' light should go out, should display '0' (or maybe '2', I
forget)
Do you know which color wire (red, clear, black) goes
to which festoon
connector (TP1, TP2, TP3, TP4)?
I would leave them all disconnected for the moment; you don't need them. One
is the 'boot' switch on the console, and its ground. The other is the 'boot
on
power on enable' (a duplicate of S1-2), and its ground. Since we're trying to
manually start the ROM console from the front console, they aren't needed for
that.
I don't recall offhand which one connects to which - I will have to check.
Don't want to blow anything up.
Not sure it will harm anything if you connect things wrongly, but that's
not tested.
Noel