On Apr 4, 2013, at 4:40 PM, shadoooo <shadoooo at gmail.com> wrote:
I have a VAX4000-100A system, that's fully working,
except for a strange error on boot that notify about
errors in the P-cache. VMS starts up, but again it notify
that P-cache will be disabled due to high error-rate.
Probably the CPU has been damaged somehow, or it's malfunctioning
(if I'm not wrong the P-cache is integrated inside the CPU).
Anybody ever had a similar problem?
Could it be possible to find a replacement CPU somewhere,
not at terrible cost?
You'd be looking for a KA52 CPU board. I imagine the 100A is
upwards compatible with the KA53 and KA54 (faster versions of
the same NVAX-based board), which may or may not be easier to
find. The KA52 is DEC part 54-21797-01; it's also the same
as the MicroVAX 3100/90 board. There's one on eBay here:
$275 or best offer (good bet if you're in the US).
The NVAX has pretty much everything integrated in the one
chip, and the P-cache is its tiny 8K first-level cache;
you'd have to replace the entire CPU, at which point you
might as well just replace the motherboard.