Subject: RE: Unexpected problems, part 2
To: 'Brian Chase' <>
From: Antonio Carlini <>
List: port-vax
Date: 05/19/2003 22:04:22
> To answer this, i tried to CONTINUE and it picked up where it=20
> stopped, including telnet session ... i'm kinda puzzled as to=20
> how this could ever work :) I stopped it again during make=20
> install for tk just to try this CONTINUE thingy :)

When the console is entered via BREAK (or rather via whatever
HW interrupt the serial controller generates when it sees
a BREAK) the console saves all the state. When you
CONTINUE, it puts it all back. Obviously if you go
mangling registers or causing an I/O side effect, then
you may find things go ga-ga. But generally it works
quite well.

> Another question i thought of, at the risk of sounding silly:=20
> is this break to console thing handled by some interrupt or=20
> something ? Shouldn't OS be able to hook that interrupt and=20
> prevent this behavior if that is the case ?

It almost certainly is an NMI of some sort but there will
be no easy way for the OS to get in the way. The whole point
is to be able to still recover the console even when something
else decides to play at IPL 31 forever!

Head over to Manx and search for
the various technical manuals that are online.
"cpu technical" as a search term brings up a bunch.
There are no manuals anywhere that I have ever seen for
the VAXstations but the KA655 is a CVAX-based box
and the support chips will be the same as your VS3100.

> And last one for today: there is a VS 4k/90a on eBay with=20
> zero bids; assuming reserve =3D minimum bid it would cost me=20
> ~$170-200 shipped, is that a reasonable price for stripped=20
> box like that ?=20

Reasonable is in the eye of the beholder: I got mine for free,
so I would not shell out that much for one. I don't know what the
typical ebay selling price for these is - I don't even know if there
are enough selling on ebay for a typical price to make any

Someone has already
bid =A350 and the reserve has not been met. I assume you want to
ship it to the US, in which case it could set you back another
=A355 minimum on top of the auction price.

(I checked with the Parcelforce website: 5kg, 49x40x11 cm).=20

Every extra kilo seems to be another =A34-=A35 on top.

Aren't there any nearer?



Antonio Carlini