Help with my PDP 11/73

From: Charles H. Dickman <chd_1_at_nktelco.net>
Date: Mon Feb 17 19:44:00 2003

Ethan Dicks wrote:

>--- chu_at_verizon.net wrote:
>
>
>>I runs the self test loop correctly.
>>However, when I try to boot
>>either DU0 or MU0 the machine gets
>>hung up.
>>
>>
>
>Do you have a complete grant chain? Gaps in the backplane
>will also cause that behavior. You need all the cards "next"
>to each other (according to the routing of your grant signals
>which differs, depending on which backplane you have).
>
>If you have a BA23, your grant goes something like this...
>
    0 A-B
           V

>1 A-B
> v
>2 A-B
> v
>3 A-B -> C-D
> v
>4 A-B <- C-D
> v
>5 A-B -> C-D
> v
>6 A-B <- C-D
>
>...etc., down to slot 9. Other backplanes are different (some all
>sinusoidal, some straight down).
>
I think there are *3* straight down slots before the first *serpentine*
slot in the BA23. :-)

>-ethan
>
>
-chuck
Received on Mon Feb 17 2003 - 19:44:00 GMT