[Coco] CoCo in France

Neil Cherry ncherry at linuxha.com
Sun Feb 10 12:15:48 EST 2019

On 2/10/19 10:59 AM, Francis Swygert wrote:
> From: Carlos Camacho <idevgames at gmail.com>
> Let me recap my previous post... 1) NTSC Coco (mine) 2) NTSC TV (his) 3) He's using a
> step down transformer 4) He says other video game consoles (NTSC) are working with his 
> transformer and his NTSC TV
> I asked him to try the RF output to the NTSC. He says that too has no video.  I asked
> him to turn on the machine and enter the SOUND 100,10 command. He reported no sound on
> the audio out. I need to have him try the sound test again over RF.
> I was also thinking a difference in the 50hz vs 60hz. Could it be the 'other retro'
> systems he mentions (that he bought from the US) have less of an issue producing a
> video if his transformer is handling the hz as is expected. ie a 30+ year old system vs
> a 10+ year old system.
> ================================

> Since the CoCo converts from AC to DC internally the 50hz vs. 60hz shouldn't matter.
> AFAIK there is no use of direct AC for anything. Since this is a CoCo1 it is possible
> that one or more chips got dislodged during shipment. You might want to have him crack
> the case open and push down on all socketed chips. Sounds like maybe a RAM, the SAM, or
> 6809 might be up in the socket enough to not get a good connection.

I disagree, I've seen transformers that are 60Hz transformers. They don't
like 50HZ. If that is the case I'd expect the transformer to get hot. I'd
also check the voltages as they'll be out of whack (I don't recall if you
mentioned that this was already done).


I recall the mention of the Atari VCS (2600) and that has an external
wall wart.

I just took a look at the schematic and I'd be most concerned with the
5v off the 723c (TP12). Though I'm not sure if the schematic matches the
CoCo 1 he has.

Since I don't know the individual's capability, do not recommend using
a scope (especially on the AC side).

Linux Home Automation         Neil Cherry       ncherry at linuxha.com
http://www.linuxha.com/                         Main site
http://linuxha.blogspot.com/                    My HA Blog
Author of:    	Linux Smart Homes For Dummies

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