On Tue, 18 Feb 2003 Robertdkeys@aol.com wrote:

> Following up on Isildur's CMD 220 problems..... They just hit me.
> I was building a KA650 system overnight, and the build went fine,
> but, one of the last things was to copy a kernel to root in my
> cmdline invocation string.  It failed to do that.  When I checked it
> this morning, it failed all drive recognition.  Since I had similar drive
> recognition problems at speed (if you call a KA650 speedy relative
> to a KA630), on a lark, I changed boardsets back to a KA630.
> It is now working.  Thus, some possible conclusions are that the board
> is marginal at speed, or something is quirky about using it with KA650
> boardsets, or it may be overheating under load, and a chip is marginal.
> I am sort of expecting the latter first, and maybe the former second, and
> not anything really to do with the KA650 boardset.  Oh, well, back to
> Mach 1, rather than warp speed Scotty.....(:+\\.....
> 
> That makes a sample size of 2 out of 2 with the problem.  Anyone else
> see this kind of thing?

I suspect that the problem is in the driver interacting with the
hardware. Probably doing some things in the wrong order, and on a bad day,
the software plays with the hardware before the hardware things it should,
and after that the hardware don't react as the software expect, and
everything freezes.
So, running on a slower machine increases the chances of things working
fine.

The question is only: what? On a real UDA-50/KDA-50 it do work, so the
problem is perhaps that NetBSD is violating the protocol, but the DEC
controllers handle that and survive, while the CMD controller don't.

There are one or two known examples where the CMS and DEC controllers do
things differently. If the driver do things the right way, it will work,
but if the driver is "cheating", it will work on the DEC controller, but
not the CMD.

Someone should really dig into this.
Unfortunately I don't have any documentation on the MSCP protocol,
otherwise I would already be at it.

	Johnny

Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt@update.uu.se           ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol