[Coco] is there any existing 6847 output to RGB ? (for coco2)

didier derny didier at aida.org
Thu Feb 19 16:01:08 EST 2015


You are right, it's PAL, for SECAM delay lines are needed, they are not on the schematics

That’s why commodore product never produced a SECAM signal  

--
Didier


-----Message d'origine-----
De : Coco [mailto:coco-bounces at maltedmedia.com] De la part de Zippster
Envoyé : jeudi 19 février 2015 21:54
À : CoCoList for Color Computer Enthusiasts
Objet : Re: [Coco] is there any existing 6847 output to RGB ? (for coco2)

Not familiar with the SECAM standard, but the flip-flop is clearly used to adjust the sync.

- Ed


> On Feb 19, 2015, at 2:50 PM, didier derny <didier at aida.org> wrote:
> 
> When this machine was sold, it was not so common to find a TV with PAL 
> Most were only SECAM, PAL+SECAM were really expensive
> 
> Later PAL+SECAM TV around 1990 where very common
> 
> 
> 
> -----Message d'origine-----
> De : Coco [mailto:coco-bounces at maltedmedia.com] De la part de Luis 
> Antoniosi (CoCoDemus) Envoyé : jeudi 19 février 2015 21:43 À : 
> CoCoList for Color Computer Enthusiasts Objet : Re: [Coco] is there 
> any existing 6847 output to RGB ? (for coco2)
> 
> It's flip-flop. It must be used to convert the NTSC sync to PAL sync.
> 
> 
> Luis Felipe Antoniosi
> 
> 
> 
> On Thu, Feb 19, 2015 at 3:36 PM, didier derny <didier at aida.org> wrote:
> 
>> The schematics I discovered:  http://6809.eu/schema_alice4k.png
>> The mc10 schematics:          http://6809.eu/schema_mc10.png
>> 
>> --
>> didier
>> 
>> -----Message d'origine-----
>> De : Coco [mailto:coco-bounces at maltedmedia.com] De la part de 
>> Zippster Envoyé : jeudi 19 février 2015 21:28 À : CoCoList for Color 
>> Computer Enthusiasts Objet : Re: [Coco] is there any existing 6847 
>> output to RGB ? (for coco2)
>> 
>> Yes, if it’s just a bunch of transistors (no comparators or adc) then 
>> it must be mixing the component signals to RGB while keeping it all analog.
>> 
>> I’m working on one (Digitize —> RGB —> DAC —> VGA) but have a way to 
>> go yet.
>> 
>> - Ed
>> 
>> 
>>> On Feb 19, 2015, at 2:16 PM, Luis Antoniosi (CoCoDemus) <
>> retrocanada76 at gmail.com> wrote:
>>> 
>>> Well I do have a coco2 peritel with a RGB output for SCART TVs. It 
>>> does everything on transistors, actually a transistor plantation...
>>> 
>>> I think it does a YCbCr -> RGB conversion. The VDG outputs YCbCr.
>>> 
>>> 
>>> Luis Felipe Antoniosi
>>> 
>>> 
>>> 
>>> On Thu, Feb 19, 2015 at 3:04 PM, didier derny <didier at aida.org> wrote:
>>> 
>>>> Is there any existing 6847 output to  rgb board / schematics
>>>> 
>>>> 
>>>> 
>>>> I've just seen the pinout of a RGB video connector
>>>> 
>>>> But the video in the machine is done by a 6847
>>>> 
>>>> 
>>>> 
>>>> The schematics are hard to read  and there are a lot of transistors
>>>> 
>>>> Between the video signal on the 6847 and the connector.
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
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