PDP-8 backplane -- was Re: PDP-8 case - test-drb@ccmp.vtda.org

19 Nov 2001

Omnibus dones not have a unibus/qbus grant chain.

the general organisation is anywhere it fits generally works save for cards
that have over the top connections.

Allison

-----Original Message-----
From: Pete Turnbull &lt;pete(a)dunnington.u-net.com&gt;
To: classiccmp(a)classiccmp.org &lt;classiccmp(a)classiccmp.org&gt;
Date: Tuesday, November 20, 2001 3:52 AM
Subject: PDP-8 backplane -- was Re: PDP-8 case

...
 On Nov 20,  0:53, Tony Duell wrote:
  Since you can put options with top connectors
anywhere in the backplane,
 there would seem to be little point in having special foam over the front
 slots only. 
That reminds me... supplementary question:  The machine had gaps between
some of the cards.  It's over 20 years since I used a PDP-8 for real, and
in those days I wasn't usually allowed at the innards.  The gaps don't
matter, do they?  There's no grant chain like in a Unibus, AFAIR.   The
-8/E is an Omnibus machine, of course.

--
Pete Peter Turnbull
 Network Manager
 University of York