Hi !

On Wed, 1 Mar 2000 carlini@bulean.lkg.dec.com wrote:
> >I didn't enable backup cache on the KA660. There is only about half a page on
> >this, and i didn't find the addresses of the BCIDX and his friends. But the
> >KA660 ist very fast, maybe the PROM enables bcache ?
> 
> I recall saying I'd look at the KA660 docs. I did look and you are right it
> does have very little info. It does however say that the Bcache is controlled
> by something called the C-chip. Now the VAX 4000-300 (KA670) has something
> called the C-chip and looking at EK-KA670-TM I see a list of 10 IPRs used to
> control this C-chip. The KA670 docs describe the backup cache in considerable
> detail. IIRC, you did the KA670 support anyway, so try using the same code for
> the KA660 backup cache. (It may well be that the console firmware initialises
> the bcache and turns it on anyway - at least using the bcache control registers
> you should be able to tell whether it is on or not!). If you don't have the
> KA670 docs and don't have the info from anywhere else, let me know and I'll
> desribe the KA670 stuff.

Ok, don't have these docs here, i just have a KA660 and a KA680 TM. (But i
don't own the machines for these docs :-). I did the KA670 stuff from the KA43,
i even don't know, if i really enable the full BCache on the KA670, maybe it
has some bigger capacity like the KA43. I don't have the KA670-TM here, but
i'll try to rip off the cache stuff there and put it into the KA660 port for
testing.

> >But if you have the docs for the KA48, what is wrong here:
> 
> I don't really have any more to offer on the KA48 (4000-VLC). If you have time
> to burn try:
> 	- Set DIAG in CCR
> 	- write cache TAG (just the tags, not the data)
> 	- leave BEHR alone
> 	- FLUSH in CCR
> 	- ENABLE in CCR and turn off DIAG

I tried nearly every way. I also did this thing, even left DIAG on while
running, it's always the same problem. As soon as i enable cache, the machine
crashes some show time later. The tag value i wrote was 0x80000000 for the
correct parity bit, i also tried 0, i left out this init, i did everything i
could imagine.

> i.e. don't go testing anything, just write the tags and flush the cache.
> 
> Other than that, I have no idea.

Shit. This means, the VLC will never be completely useable. I also put VMS on
it again. But it looks nice :-)

...Michael

-- 
 Michael@camaronet.de, Rottweil/Germany, http://www.camaronet.de
 Visit the german VAXpage: http://www.vaxpower.de