Re: C64 S-Video Output Circuit ( was: Re: C16/Plus4 )

From: Gerrit Heitsch <>
Date: Tue, 01 Nov 2011 01:00:32 +0100
Message-ID: <>
On 11/01/2011 12:28 AM, Tod D. Ihde wrote:
> On 10/31/2011 6:02 AM, Gerrit Heitsch wrote:

>> From a C64 forum I got a small circuit (2 transistors plus a few
>> passive components) that one can use instead of the modulator. You get
>> S-Video only at the output then (no CVBS anymore), but the picture is
>> really good. I haven't tried it on a C16 yet, but I see no reason why it
>> shouldn't work there too.
> Gerrit, I'm sure I'm missing something here, but my C64 has separate
> chroma / luma out - am I remembering correctly that older models only
> had composite, while newer models (such as mine) had both? Is that the
> reason for this circuit on the 64?

No, the reason is that the signals are routed _through_ the modulator 
(where they are used to generate the RF and the composite signal) and 
this degrades the signals. Depending on the modulator in your C64 and 
the monitor you use, the difference can be quite striking.

On the C16 the modulator feeds part of the chroma signal back onto the 
Luma signal which means you can't really use S-Video at all without 


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Received on 2011-11-01 01:00:06

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