11/04 Project

[Noel Chiappa]

    > 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