25 Oct
2013
25 Oct
'13
10:51 a.m.
> <Alex D wrote:>
> While this is all fine for dual cards, but how does this configuration
> handle quad cards?
<Roe Peterson wrote:>
As long as quad-width cards don't mess about on the
right-hand side
connectors (most of them don't) you can use any quad-width slot, whether
its wired QQ/CD or QQ/QQ.
I'm confused here. All the required signals for system operation are on the AB side
(you call it QQ?). Correct? What is on the CD side then?
I always thought that the CD side was like a 'private' communication bus, as in
the M8013 talks to the M8014. I'm not getting something here.
How would a quad card not mess about on the right hand side? The only thing I can think
of, is this. If the right hand side (CD) is wired for AB there is power
on there. The quad card would just have to stay away from those pins. Does the CD part of
the quad card make use of the AB signals present?
I'm going by this:
http://www.ibiblio.org/pub/academic/computer-science/history/pdp-11/hardwar…
and my 'microcomputers and memories (1982)' handbook.
I'm feeling really 'dumb' right now...
cheers
--
alex