[Coco] CoCo I 26-3004A and "fix"

[Bruce W. Calkins]

There is a model number printed near the cartridge port on the board.  
Early CoCo 1s had a "B", "C", "D", or "E" at the end of the number.  "F" 
boards ended in a 283 IIRC.

I had 2 "F" board CoCos, one with the fix that worked OK and one without 
that would lock up after running a while.

Bruce W.


On 01/07/2018 10:00 PM, Oswaldo Aquique wrote:
> Thanks!
>
> Not sure where to look if this is a "F" board, but did surprise me when opened my CoCo I
>
> Sent from my iPhone
>
>> On Jan 7, 2018, at 6:55 PM, Bruce W. Calkins <brucewcalkins at charter.net> wrote:
>>
>> That looks like the infamous "F" (283?) board timing fix.
>>
>> Bruce W.
>>
>>
>>
>>> On 01/07/2018 08:48 PM, Oswaldo Aquique wrote:
>>> Hi,
>>> In preparation to attempt the CoCo I composite output circuit, I opened the CoCo 1 I recently purchased (26-3004A, 64K) and found it has a “patch” or “fix” in the motherboard.
>>>
>>> Just curious about what this is for. Has anyone seen something like this?
>>>
>>> I have posted a couple of pictures at https://1drv.ms/f/s!Au1yAYzNT_IAgbS1BqEB2Is4PcYmUO0
>>>
>>> It seems I’ll need to relocate this fix if I want to play with the 1372
>>>
>>> Thanks,
>>> Oswaldo
>>>
>>> Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10
>>>
>>>
>>>