Connecting a BC80M cable to a RLV12 controller

[David Betz]

Okay, thanks to all of your help (and Julian's and Patrick's) I now  
have the RL01 drive connected to the 11/73 and the fault light goes  
off when I power on both units. Now I just have to figure out how to  
boot the RL01!

On Nov 10, 2005, at 5:34 PM, Ethan Dicks wrote:

> On 11/10/05, David Betz <dbetz at xlisper.mv.com> wrote:
>> I finally got a drive select plug for my RL01 drive and would like to
>> try connecting it to my 11/73 but I find that the cable that is
>> supposed to plug into the RLV12 controller isn't keyed so it can go
>> in either way. How do I tell what the correct orientation is for this
>> cable?
>
> Look at the connector - there is no enforced keying, true, but most  
> Bergs
> I've seen have a pair of sub-mm-wide grooves that parallel the  
> connector
> pins - those grooves are on the same side as the occasionally-seen  
> keying notch.
>
> So... looking at the connector on the controller end, I'd expect to
> see a 2mm ^ 2 notch in the middle of the connector... that side (up)
> would go with the grooved side of the cable.
>
>> I'm assuming that if I plug it in backwards I'll fry the  
>> controller and/or drive.
>
> Nope.  DEC stuff is nice and robust that way.
>
>  The only markings on the end of the cable
>> that connects to the controller are the manufacturers name "Berg" and
>> the letters A and B near one end and VV and UU near the other end.
>> How should this cable be inserted into the RLV12?
>
> If you have markings on the connector, then it's much easier... I
> don't have an RLV12 in front of me, but the standard blue DEC Berg PCB
> connector has pin markings embossed into the face of the plastic, does
> it not?  If not, then start by aligning the A-side of the connector
> with the left side of the connector on the controller as you look at
> it (perhaps it's marked with a pin-1 indicator, or perhaps the PCB has
> a square pin)
>
> In any case, try what looks like the right choice, and if your FAULT
> light is still powered on, flip the connector and the FAULT light
> should be off (when both the drive and the CPU are on).
>
> -ethan
>