Subject: Re: Misc 7000 class boards --- what are they?
To: Mattias Nordlund <>
From: Brian Hechinger <>
List: port-vax
Date: 01/23/2001 14:16:11
Mattias Nordlund drunkenly mumbled...
> Something called "CLOCK & ARBITRATION MODULE" I have no Idea.
> Will open up the VAX7620 here and see if I have such a card.

this is most likely 100% nessesary for your backplane to operate.  what i see
(just from the name alone) is that the clock signal, and the arbitration of
who gets to talk when, resides on this module.  without it, your backplane
won't be able to function.

a lot of times this will be integrated into the system board (if you can only
have one system board, ala sun3 VME systems) otherwise, it must be seperate
since you can only have one of these in a system.  some are built directly
into the backplane for simplicity and the regaining of a slot, but DEC seems
to like to keep everything seperate (if you blow your clock crystal all you
have to do is swap out a single card instead of your entire backplane)