Re: 6567 revisions (was Re: 264/TED/Plus4 Story)

From: Gerrit Heitsch <gerrit_at_laosinh.s.bawue.de>
Date: Thu, 25 Aug 2011 18:13:03 +0200
Message-ID: <4E56748F.9020107@laosinh.s.bawue.de>
On 08/24/2011 10:10 PM, Marko Mäkelä wrote:
>
> As far as I remember, the 6569R1 and 6569R3 generate 5 luminance levels.
> I do not remember the 6567R8 that well, but I guess it should generate 5
> levels too.
>
> It is the 6569R5 and later that generate 9 levels.

Hm, I own a 6569R3, some 6569R5 and some 8565R2. I don't notice any 
difference in picture quality between the 6569-Revisions, the 8565R2 
seems to provide a slighty brighter picture. It also has the 
'grey-dots-bug'. If you write to the background or border color register 
(even if this doesn't change the contents) you get a grey dot on the 
screen at the moment the register is written to. The intro for Giana 
Sisters does show that quite nicely. Looks like a kind of 'snow effect' 
if done right. This doesn't happen on a 6569. On some 8565-VICs it goes 
away once the chip warms up.

The bug is also present with TED and the VIC used in the C128. It seems 
as if it got introduced with the switch to HMOS.


> Were there any 6569R2 or 6569R4?

Very likely... Same for the 8565R1... It's possible that those didn't 
work right though and never made it beyond the testing stage.

  Gerrit


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Received on 2011-08-25 17:00:27

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