Resolved: Re: 11/34 sanity check

Johnny Billquist bqt at
Sun Apr 26 18:04:36 CDT 2015

On 2015-04-27 00:50, Mike Ross wrote:
> That's harsh, JS. Incorrect pin markings are not something that would
> be anywhere near the top of my list, or anyone else's I suspect. One
> does not casually reverse the installation of cables just to see if
> maybe it will work!

Actually.... I often have done so, just because of this. But I would 
never have thought about it, or remembered to suggest it in this case, 
so that was a really good catch by Joerg.


> Mike
> On Mon, Apr 27, 2015 at 9:41 AM, js at <js at> wrote:
>> On 4/26/2015 12:58 PM, Josh Dersch wrote:
>>>> I've seen this, when the 20 pin cable from M7859 to the console panel
>>>> is plugged in reversed.
>>>> Don't trust the marked pin 1 wire: sometimes DEC manufacturing twisted
>>>> the cables.
>>>> hope this helps,
>>>> Joerg
>>> All LEDs "glowing dark"?
>>> And sure enough, I flipped the cable around and things are much happier,
>>> the front panel is completely responsive and the CPU and bus seem to be
>>> working but I'll need to spend some more time with it to test stuff out.
>>> That'll learn me to trust Pin-1 markings on DEC stuff :).
>>> Thanks all for the suggestions, it's all been very educational...
>>> - Josh
>> J, to save the time of those posting, it's more or less assumed you've
>> already tried the obvious things before asking for help.    Otherwise,
>> posters are -- for example -- left having to first question whether a
>> machine is even plugged in to the wall or not.
>> - J

Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

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