PDP-11/73 booting!

[Ethan Dicks]

On 11/16/05, David Betz <dbetz at xlisper.mv.com> wrote:
> No fault light (and it isn't burned out), the white load light (with
> the "0" on it) lights.

That's a very good sign.

> So, I suppose that means that the cables are probably bad?

It's possible.  I've had problems with RL/RK cables that have been
bent too many times.

> BTW, I
> have the cable plugged into the top connector on the RL01 and the
> terminator on the bottom. Is that correct?

It doesn't matter - there's about 2 cm of 40-pin ribbon cable
connecting the two, but it really doesn't matter which one takes in
the signals and which one has the terminator.  Swap them if you feel
unsure.

I suppose you could test the terminator to ensure it's not defective. 
Additionally, I suppose you could have a problem with some of the
drive or controller electronics, but I don't recall that being a
common issue - when either the boards in the drive or the controller
were bad somehow, I remember things really didn't work (the board not
showing up in memory, the FAULT light not going out, etc)

Check the Berg end of the controller cable - make sure you don't have
any disloged pins or wires that are pulling out of the crimp pins...
those ends are somewhat fragile (compared to IDC-type flat cables),
and I've seen some mechanical abuse.  Also, if any part of the cable
as been doubled-over hard (like to "dress" them in a cabinet), you
might try a light massage of the elbow of the crimp.  I have one
particular cable someone folded over tight that I splinted with a bit
of plastic and some tie wraps to keep it from re-flexing at the same
point - if you bent that particular cable over about 45 degrees at the
old flex point, I don't recall the symptoms, but I know it broke
something.

-ethan