Trying to get my RLV11 working

Ben Sinclair ben at
Thu Oct 29 11:52:24 CDT 2015

Thanks! I did find someone who has the bc80m cable available, which I
believe is a ribbon type of connector with a ground strap on one end,
then a round cable to the berg connector for the back of the RL02. I
think it's the cable pictured here:

Does that sound right?

The RLV11 and RLV12 seem hard to find, at least on eBay, so fixing
this one might be the way to go! Of course, I'll snag an extra if I
see one for a decent price.

Feel free to move to Iowa and help me with my PDP, Noel!

On Thu, Oct 29, 2015 at 11:38 AM, Noel Chiappa <jnc at> wrote:
>     > From: Ben Sinclair
>     > A while back I was talking to someone else who suggested using a ribbon
>     > cable from the controller to directly inside the drive.
> I've heard that suggestion too...
>     > That technically will fit if I remove the ribbon inside the drive that
>     > goes to the external connectors, but then I won't have a terminator
>     > installed. I do have a terminator though!
> The cable from the CPU would have to have two connectors on the RL02 end;
> one would plug into the drive's logic board, and the other to the outbound
> connector, where you can plug in the terminator.
> AFAIK that cable is purely a bus (i.e. no radial per-drive wires), so you
> should just be able to run it to the second connector, no issue. However,
> I'm too lazy to check to make sure that's absolutely 100% accurate. :-)
>     > I think what I really need, since I don't have a cab kit or anything,
>     > is a bc80m, which I believe is a ribbon with a ground lug on the
>     > controller side, and whatever type of connector the drive uses on the
>     > other end.
> I think you mean a Berg connector which will plug directly into the RLV11,
> not "ground lug", right? Yes, if you don't have a cab kit, that's the cable
> you need. It's not a ribbon cable, but a round cable (the connectors the
> drives use only come in regular cable form, not ribbon cable - AFAIK).
>     > Not that I can even find a cable like that anywhere currently...
> RLOx cables of _any_ kind are very hard to find. There are discussions under
> way about making new ones; there is a supply (used) of the wierd-ass
> connector that plugs into the back of the drive which could be used.
>     > I unfortunately don't have an extender card...
> Others have pointed you at Douglas; here's the page for all their
> extender cards:
> which includes a hex, but those aren't any use (that I can think of) to
> people with QBUS machines.
> (Useful things to have it you're trying to maintain a vintage PDP-11; one is,
> perforce, forced to become one's own Field Circus person - unless you're lucky
> and happen to live close to a PDP-11 hardware expert who's willing to come
> salve one's machine.)
>     > From: Johnny Billquist
>     > Well, not important. We're now beyond that point. The boards are
>     > working well enough that we can address them...
> Well, but he might still have a problem on them. Although fixing such would
> be a challenge...
>         Noel

Ben Sinclair
ben at

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