RL02 Question

[Aaron Jackson]

>     > From: Aaron Jackson
>
>     > I have tried three controllers, two r/w modules and two servo
>     > controllers. I'm beginning to think the drive is fine and there is a
>     > problem with the RLV21 controller.
>
> Err, think you mean RLV12 QBUS controller board, right?

Woops, yes! I get mixed up with the RXV21.

> Anyway, you've already tried ("three controllers") swapping that out?

As in the logic controller inside the drive. I only have one RLV12
unfortunately. Although a friend has recently purchased one, so
hopefully I can test with that soon.

> If you have, perhaps there's a problem with a cable and/or the terminator?
>
>
> However, at this point, sub-system swapping is probably not going to be the
> best way to make progress. I think you're going to have to actually debug the
> problem; i.e. dive in and work out what's happening wrong, and why, and trace
> it back to the origin.
>
> Luckily, for this generation (and before), DEC produced wonderful technical
> manuals, which go into full detail of how the thing works. With that in hand,
> the investigative process is a lot easier; you don't have to work out how the
> thihg works by looking at the prints, it's all laid out in detail. And tech
> manuals for both the RL02 drive and RLV12 controller (EK-RLV12-TD-001) are
> available online, as are the prints (MP01282 for the RLV12).
>
> So, I'd sit down with the RLV12 tech man and read through the section on the
> drive<->controller bus (section 3.3). Then start looking at what the two are
> saying to each other on the bus, and figure out what's actually going wrong.
> From there, you'll know where the source of the problem is, and can chase it
> further.
>
> I know this sounds like it would be time-consuming, but when you think about
> the time/energy you've already put into swapping things around, chasing this
> problem, it won't be.
>
> 	Noel

I have been studying the technical description manual, and the
schematics in quite some detail. I think it is time I hook up a logic
analyser to the cable between the RLV12 controller and the drive to try
and see what is going on during the initial seek. I have already checked
to see if there is a 4.1MHz clock signal (there is).

Thanks,
Aaron.