[Coco] CoCo2 black and gray video only -- need help!

[Keith Monahan]

Hey Kevin,

Thanks for the links.

Yeah I have the 20261058 PCB with the 6847T1.

Keith


On 10/25/2021 9:49 AM, Kevin Becker wrote:
> On Sun, Oct 24, 2021, at 9:52 PM, Keith Monahan via Coco wrote:
>> I have yet to find a service manual or associated schematic/BOM list for
>> a 26-3127B. If anyone knows where to find one? Color Computer Archive
>> does not seem to have it, but maybe I'm not searching good enough.
>>
> 
> This page has the best breakdown of the various CoCo models that I've found.
> http://users.digitalindigo.net/techno/coco2.html
> 
> According to that page there were multiple different motherboards all used in machines called 3127B.  I have a Korean 3127B and I'm pretty sure that one of the two NTSC service manuals (26-3026/26-3027 or 26-3134/26-3136) on the archive matched mine but I'm not in a place that I can check it right now.  Maybe, as you said, it was just similar to mine but not an exact match.
> 
> Do you have the MC6847T1 VDG?  Starting on page 89, the following book has some info about changes to machines that have the new VDG.
> 
> https://colorcomputerarchive.com/repo/Documents/Magazines/Rainbow,%20The%20-%20Full%20turn%20of%20the%20screw/FullTurn.pdf
> 
>