[Coco] Need help with composite output for CoCo

[Tormod Volden]

>> On Feb 14, 2015, at 7:37 AM, Jamie wrote:
>>
>> Hi All,
>>
>> So I'm trying to build a composite video converter for a coco 1 and I can't seem to get it to work.
>> I started with a simple design from Hot CoCo which uses a couple of transistors and a few
>> resistors and then tried Dennis' TV Buff.
>> My question is, should the output work on a modern flat screen LCD TV or do monitors with
>> composite input work differently?  The TV screen responds by going black but I'm not getting any
>> picture at all.

On Sat, Feb 14, 2015 at 3:23 PM, Zippster wrote:
> Hi Jamie,
>
> Flat screen or not you should get a picture if you are generating a valid composite
> signal.  Can you link the schematic of the circuit you’re using and pics of your installation?

The composite signal from a CoCo, if it is generated almost straight
from the 6847 like on the Dragon, might have trouble convincing modern
LCD TVs and monitors. An older LCD monitor with composite or S-video
input can be more forgiving. I cannot use my nice Dell 2007WPFb but my
Acer AL1731 works fine. A Samsung LCD TV that I tried did also not
work.

We have a little list here, probably not the same results on your
composite circuitry, but it gives an idea:
http://archive.worldofdragon.org/index.php?title=Monitors

Tormod