help needed: problem with UNIBUS access on my PDP-11/70 - test-drb@ccmp.vtda.org

17 Jul 2002

...
  Gooijen H wrote:
  By experiment I will check the NPR wire of the
other
 UNIBUS slots. You know why once you have seen the
 backplane of an 11/70.  
 Johnny Billquist &lt;bqt(a)update.uu.se&gt; wrote:
  Huh? It's no more difficult checking the NPR
wire in the 
 11/70, than on any other Unibus backplane. And it *is*
 rather simple to see if the jumper is there or not.  
 On the 11/70 Mike and I have been working on, the NPR grant 
 jumpers were wrapped before most of the other wiring, rather
 than after.  This makes it fairly difficult to see them. 
On the 11/70 backplane I have, the NPR grant is also wired
before all other wires. That is what makes me nervous when I
start thinking about cutting a wire for a DMA device.
A DD11-DK 9 slot gen purpose backplane is a lot easier when
it comes to accessing the NPR wires. I agree that *looking*
with a good light source is not too difficult. 

- Henk.