PDP-11/04-34 Programmer's Console manual error

Camiel Vanderhoeven iamcamiel at gmail.com
Tue Mar 29 08:13:04 CDT 2016

It's done on purpose, sort of an initiation rite. All traces of this
conversation will be wiped out so future /34 owners won't miss out on this!


-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Jörg Hoppe
Sent: dinsdag 29 maart 2016 13:28
To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
Subject: Re: PDP-11/04-34 Programmer's Console manual error


this is something every '34 owner must go through. Welcome to the club ;-)


Am 29.03.2016 um 13:19 schrieb Noel Chiappa:
> So, something I just found out the hard way, while debugging another 
> 'situation' with a PDP-11/04:
> The KY11-LB Programmer's Console maintainence manual contains a major 
> error, in describing the configuration of the 20-conductor flat cable 
> that connectors the front panel and the UNIBUS interface module 
> (M7859). This is covered in Chapter 9, "Installation", which includes two
figures, Figures 9-4 and 9-5.
> Those figures show the 20-conductor flat cable with the red edge 
> stripe toward the outer edge of the front panel PCB (correct), and 
> also toward the outer edge of the M7859 (WRONG). On the M7859, the red 
> stripe edge needs to be oriented _away_ from the outer edge of the board.
> If it is plugged in as shown in these figures, the machine will not
> the four 'RUN/SR DISP/BUS ERR/MAINT' lights will be on, but nothing 
> else, and it will not respond to any keys. Fortunately, plugging the 
> cable in reversed does not damage anything; simply reverse the cable.
> 	Noel

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