[Coco] Model No. 26-3127B motherboard

[Bob Devries]

Hmm,

Interesting comment regarding 64K daughter boards.

Here in Australia, all the 26-3127 cocos had the daughter board as supplied 
by Tandy. Any 16K coco2 was most often upgraded with the daughter board if 
done by Tandy in-house, or with 2 64k x 4 bit chips (41464 or similar) if 
done by third party hardware people or users.

I know I upgraded a dozen of them in that manner at one stage for a Tandy 
store in exchange for a 128k Coco3 (my first Coco3).

Also, the 41464 chips from the upgraded Coco3 could be used to upgrade the 
16k coco.

--
Regards, Bob Devries, Dalby, Queensland, Australia

Isaiah 50:4 The sovereign Lord has given me
the capacity to be his spokesman,
so that I know how to help the weary.

website: http://www.home.gil.com.au/~bdevasl
my blog: http://bdevries.invigorated.org/

----- Original Message ----- 
From: "Bruce W. Calkins" <brucewcalkins at charter.net>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Sunday, March 08, 2009 6:03 AM
Subject: Re: [Coco] Model No. 26-3127B motherboard


> Mike has it concisely correct.  It does appear that the 64K expansion 
> cards are not all that common.  I have seen two in the dozens of CoCos 
> that I have opened up.  But there are people who have opened up as many or 
> more than I and not seen one.  The sockets for the 16kx4 chips will also 
> take the 64kx4 chips that we pull from our CoCo 3s for the 512k expansion. 
> These might use a little less power to run that the expansion card.
>
>
>
> Bruce W.
>
>
>
>
>
>
>
>
>
> ----- Original Message ----- 
> From: "Mike Pepe"
>
>> Alan:
>>
>> 1: That's a 64K memory expansion card.
>>
>> 2: a pair of 16kx4 chips (41416 or similar) are what go in the now empty
>> sockets
>>
>> 3: the 64k/128k jumpers refer to the ROM size. 64 kilobit (8k x 8) for
>> standard color basic, 128 kilobit (16k x 8) for extended basic
>>
>>
>>
>>> -----Original Message-----
>>> From: On Behalf Of N8WQ
>>>
>>> Folks,
>>> Today I took apart a 26-3127B for the first time.
>>> I have a couple of questions that need answered.
>>> If you have time go to http://exwn8jef.googlepages.com/cocoprojects
>>> and see if you can help me out.
>>>
>>> Also does anyone have a scanned copy of 26-3127B service manual?
>>>
>>> Thanks and have a great day.
>>>
>>> Alan
>>>
>>> --
>>> N8WQ - Canal Winchester, Ohio
>>> http://exwn8jef.googlepages.com/home
>>>
>>>
>>>
>>> --
>>> Coco mailing list
>>> Coco at maltedmedia.com
>>> http://five.pairlist.net/mailman/listinfo/coco
>>
>>
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>
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