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Re: rtVAX300 .. need help..

>> I am very impressed.  I do not think my German would be as good in
>> the analogous case.
> Thanks for the flowers :-)

Bitte. :-)  (Ich spreche ein bißchen, aber sehr bißchen.)

>> I don't know how your rtVAX 300 does interrupt arbitration and
>> mapping.  That information might be [...]
> Ther si something in the Hardware manual about this in a rtVAX300,
> that wasn't te problem, I wanted some hints about other VAXen to just
> understand the related NetBSD files.

Ah!  I can, maybe, help with the KA630 - though that might not be all
that noteworthy, as I'd hazard a guess that it may be one of the
better-known implementations here.

> It is interesting how DEC migrated from a "all known, all standard"
> system on UNIBUS and QBUS where any register address and bit was
> known to a wide varying family of machines where things are new all
> the time.

All documented, I feel sure...but the documentation was
internal-use-only. :(  I still recall when a colleague of mine found a
hardware bug in the KA630, one that likely wouldn't've been nearly as
much of a mystery if we'd had schematics.  (AIUI anyone with a KA630
could still get the bugfix applied free for as long as DEC Field
Service existed - you just had to know which ECO to ask for.  Not that
it is likely to cause anyone much trouble, or it would have been found
far earlier.)

> Exactly this is what makes me trouble since I don't know if a feature
> is "standard" or an one-off occurrence.

Well, when the "standard" (the VARM) is getting rewritten for each new
implementation, I'm not sure the difference is as meaningful as one
might wish. :(  (Okay, that may be unfair; I don't know to what extent
VARMs came out at least as often as new implementations.)

>> I fear this is not very helpful. 
> You are just wrong here.

Of all the things I wrote in that email, that's probably the one I'm
happiest to be wrong about!

>> [...], I don't have much to offer.  Not because I don't want to
>> help, but because I have no help to give.
> That's not true.  Just keep talking with me, this helps a lot.

Well, that much I can do. :-)

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