RLV11 in VAX 4000-400?

From: Peter Turnbull <pete_at_dunnington.u-net.com>
Date: Fri Jul 11 13:10:00 2003

On Jul 11, 12:02, Jochen Kunz wrote:

> I can see the two small lines going to BC1 and BD2 on the M8013.
> Do you know what these signals are used for?

(You mean BC1 and BD1, not BD2)

No, but it's nothing that's used in any normal system. They don't
connect to the M8014, nor to anything a standard 18-bit system can
access (they're SSPARE4 and SSPARE5 bus lines, normally unused,
although the 11/03 and soe contemporary options did put odd signals
there). My guess is they're for some manufacturing test, because a
quick perusal of the RLV11 Technical Manual didn't tell me anthing
either.

> If I see this correct, they don't go to the M8014. They just put some
> signals onto the bus. So some sugery would solve the problem?

The M8013 I just pulled from one of my (22-bit PDP-11) systems has
those two tracks cut, and it's been working fine since I've had it
(almost 15 years).

If you hold the M8013 component side up, with the contact fingers
towards you, they're the two thin tracks in the shape of an inverted
"L" which come from the 15th and 16th contacts on the third set.
 They're cut about halfway between the contact finger and the corner of
the inverted "L".

I've had a look, but I can't find the ECO relating to this. Either my
microfiche is too old (quite likely -- it only lists up to CS Rev F and
my RLV11 is Rev H) or I saw it somewhere like in one of the Micronotes
(which I no longer have, and sadly the ones available online are only a
fraction of the total issued).

> > That fixes the electrical
> > problem, but whether you can find a VAX OS that knows to only use
DMA
> > in the bottom 256K of memory is another matter.
> This would fit to NetBSD. NetBSD uses only one softwareinterface
> for UniBus and QBus...

Go for it...

-- 
Pete						Peter Turnbull
						Network Manager
						University of York
Received on Fri Jul 11 2003 - 13:10:00 BST

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