Re: 6569 vs. 8565

From: Gerrit Heitsch <>
Date: Mon, 26 Nov 2012 20:04:43 +0100
Message-ID: <>
On 11/26/2012 07:43 PM, wrote:
> All of this I understand but on the same monitor (a TV studio monitor), the 8565 gives virtually _no_ artefacts. Of course the picture from 8565 is not 100% perfect either, and for the good reasons you described above but it does not disturb. Here those effects are actually quite disturbing..

Maybe you have a particularly 'bad' 6569 in that respect. The chip is 
NMOS, but gets fed the 17.73 MHz (4 x color clock) which it then uses to 
generate the differently phased 4.43 MHz it uses to generate the color 

That's a pretty hefty job and probably the reason why the 6569 still 
needs +12V instead of running completly on +5V like the HMOS-II 8565.

Maybe that generator in your 6569 is a bit 'off' with respect to signal 
quality? Have you tried a different 8701?

Also, some people claim, that the old clock generator (74LS629 and 
MC4044P on the 250407 boards) produces less jitter than the 8701.


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Received on 2012-11-26 20:00:10

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