RK8E controller board revisions - Chaos ahead, help needed

[Don North]

Check out the PDP-8e ECO log document on bitsavers.org:

http://www.bitsavers.org/pdf/dec/pdp8/pdp8e/PDP-8E_ECO_LOG_Dec74.pdf

Pages 313-315 have details on the M7104-6 modules

Don



On 4/26/2010 12:02 PM, Philipp Hachtmann wrote:
> Hi,
>
>> The B2, B1, and C are the etch levels of the boards. The 310D means the
>> board was made in  1973 or maybe 1983 during the 10th week. The D is the
>> eco/fco rev of the board.
> Ok, etch level is somewhat clear to me - it's marked in copper. And 
> the eco/fco stuff - how to keep track of that? And what stands the D 
> really for? A combination of board revision and eco level?
> I'd like to know how to get the right schematic etc.
> In the RK8E schematics for example I read "revision a" for the board. 
> Does that refer to the etch revision or the overall version of the 
> board including ecos and probably applied fcos?
> Is there some kind of straightforward record of eco and fco levels?
> What about the relationship between factory installed ecos and fcos? 
> Are they equivalent?
>
> To me it's all not that clear...
>
> Regards,
>
> Philipp
>
>
>>
>> I still have some other thing to go over with you off list, and will 
>> try to
>> get to them this week.
>>
>> Paul
>> On Mon, Apr 26, 2010 at 7:51 AM, Philipp Hachtmann <hachti at hachti.de> 
>> wrote:
>>
>>> Hi folks,
>>>
>>> I'm currently dealing with some RK8E Omnibus RK05 controller board 
>>> sets.
>>>
>>> I was unable to assemble even one stable RK8E from the stuff. I 
>>> assume a
>>> high failure rate. But I also assume that I have board revision 
>>> problems.
>>> I've been told that several revisions existed. And that there were
>>> compatibility issues and some kind of paper (which I do not have) 
>>> telling
>>> what fits what.
>>> I don't even know if the revisions are PCB revisions like "M7104 B2"
>>> written in the etch or if there are also FCOs or alike that make 
>>> boards with
>>> same etch incompatible to other boards.
>>>
>>> My personal RK8E passes all tests. It consists of:
>>>
>>> M7104 B2
>>> M7105 B1
>>> M7106 C
>>>
>>> But I have other boards flying around here as well.
>>>
>>> Do stamps like "310 D" on the backside of the boards have any 
>>> meaning with
>>> respect to board revision or FCO level?
>>>
>>> Another question is how to get different board revisions associated 
>>> with
>>> the right schematics.
>>>
>>> I strongly appreciate any piece of enlightenment since I'm currently
>>> getting depressed by that stuff. Even if I have bad boards - it 
>>> won't make
>>> sense to try to repair something if the whole is inconsistent in 
>>> itself.
>>>
>>> Many thanks,
>>>
>>> Philipp
>>>
>
>