PDP 11/34 rebuild

From: Peter Turnbull <pete_at_dunnington.u-net.com>
Date: Sun May 25 14:52:01 2003

On May 25, 17:32, Greg Elkin wrote:
> The 11/34a I collected recently (BA11-L chasis, H777 PSU) and had
> difficulty getting to power up is in better shape now that it's had a
> good clean ; backplane inspected and all the dust & debris removed
> from its slots (via "fart in a can", ie compressed air :), the cards
> have had their edge connectors cleaned (india rubber) to be nice and
> shiny.
>
> Switching to DC ON, the fans whirr happily and the front panel now
> has "DC ON" and "RUN" LEDs on, with 000000 on the 7seg LEDs.
>
> If I try to halt (keypad CNTRL + HLT/SS), the RUN LED stays on and
> BUS ERR LED also comes on.

FAQ. This is the result of having a 9302 terminator, whichg asserts
SACK, and a missing NPR jumper somewhere. Either you have a card
missing, or you've put a card that doesn't pass NPR into a slot where
previously there was a card that did (or you've put a small grant card
where you should have a full-size one). Ethan mentioned this in
response to one of your posts recently, and Tony (on more than one
occasion) explained in detail why this has the effect it does.

http://www.classiccmp.org/pipermail/cctalk/2003-May/022031.html
http://www.classiccmp.org/pipermail/cctalk/2003-May/022051.html

Don't feel *too* bad about it, I got caught myself with that, once.

-- 
Pete						Peter Turnbull
						Network Manager
						University of York
Received on Sun May 25 2003 - 14:52:01 BST

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