Subject: Re: Status Vax 4000/60, 400/90, 4000/vlc
To: None <>
From: Michael Kukat <>
List: port-vax
Date: 02/23/2000 18:00:47
Hi !

On Wed, 23 Feb 2000 wrote:
> >Think, it's because of the missing cache. I tried again some days ago, but i
> >don't get this cache running. It's different from KA660 cache enabling. But the
> >box runs fine, just a bit slow, and SCSI is missing on all 4000s (NCR5394).
> I've just (quickly) compared the KA48 and KA660 docs and there do seem to be
> some slight differences. The most obvious one is that the VLC only has a
> primary cache and no backup cache; so none of the registers associated with the
> backup cache exist.

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 ?

But if you have the docs for the KA48, what is wrong here:

Set DIAG in CCR, check all 8 banks (enabled by the bits in BEHR) for good
memory present, reset them to 0 in cache DATA and 0x80000000 in cache TAG, and
if everything was OK, remeber this bank control bit. After checking all banks
(all 8 are OK), i write the remembered bits to BEHR, say FLUSH in CCR and say
ENA in CCR then. (This is the only bit left 1 then). This works on KA660, but
not on KA48, so some, maybe very small, detail is different here.

I did more than you described, and the KA660 TM describes, but after reading
"The firmware sets the correct banks in BEHR", i thought checking the banks
again could be no error.

If my VLC wouldn't run that fine under VMS, i would suspect a broken cache in
my box. If someone wants to check it out, i could put a kernel with my cache
routine somewhere, but i don't expect other results than i have on my box.


--, Rottweil/Germany,
 Visit the german VAXpage: