[GreenKeys] Weird 33 keyboard problem

[Bob Camp]

Hi

Well one nice thing about the PDP-8 - you should be able to pick up  
right where you left off in the game. Magnetic memory does have it's  
advantages .....

Bob


On Sep 13, 2007, at 9:21 PM, Charles wrote:

> Thanks to both Don and Wayne for helpful suggestions. As you can
> see below, I did find the problem and it was a keyboard contact
> wire out of position. The reader is in need of repair and I have
> an old punch requiring cleanup before I install it. So it's really
> a KSR at the moment ;)
> The printer was printing exactly what it was told to do, BTW.
>
> So this afternoon, I was happily playing Adventure on my PDP-8/A
> (to which this 33 is connected) when after a couple of hundred
> lines of text, there was an awful "scrawk" noise and everything
> locked up =8^0
>
> I took the cover off yet *again* and found the belt in pretty sad
> shape, the distributor immobile, and a lever obviously out of
> position jamming the roller on the distributor clutch mechanism.
> The E-clip on the end of the roller was missing, too (20 cents at
> my local farm store). I took out the distributor shaft assembly
> and cleaned and lubed the clutch and the other moving parts in
> that area. The problem appears to have arisen because either I had
> set too much endplay in the shaft, or more likely something had
> loosened, allowing the distributor shaft to move to the right far
> enough so that particular lever had slid off the rotating "disc"
> and jammed solidly beneath the roller. After reassembly it's
> working once more (fortunately I had a spare belt).
>
> Oh, the "joys" of old hardware!
>
> -Charles
>
>
>> One of the last updates to the 33 keyboard was to put complete
>> plastic casing around the contacts.
>> I am pleased you were able to find the problem.
>> Don
>>
>> On 13 Sep 2007, at 12:22 PM, Charles wrote:
>>
>> Found it... one of the right-hand shift contact wires was
>> dislocated from its base contact!
>>
>> Nothing binding though. I'd have expected more trouble with keys
>> not "doing" anything, or sticking, not necessarily just outputting
>> the wrong code...
>>
>> I am pretty fed up working on both my 33s too! The surest way to
>> get it to screw up is to put the cover back on ;)
>
> _______________________________________________
> GreenKeys mailing list
> GreenKeys at mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/greenkeys
>