Re: VIC-II, CIA, keyboard differences

From: Gerrit Heitsch <>
Date: Sat, 10 Dec 2011 19:40:26 +0100
Message-ID: <>
On 12/09/2011 10:44 AM, Marko Mäkelä wrote:
> Interesting, I did not know that there is a difference in CIA timers
> until it was mentioned here this year.

There is software that lets you single step through a program and will 
cause problems on the new CIAs unless patched.

> On my oldest C64 (with 350ns ceramic DRAM chips), sprites flicker. I
> never tried to troubleshoot it whether it is because of the 6569R1, the
> slow DRAM, or the motherboard.

My board with the 6569R1 uses Toshiba TMM4164P-3 DRAMs. Doesn't flicker, 
not even when playing demos that open all 4 borders. It also uses a real 
PLA and not the MOS version. Maybe your VIC or some other part is not 
quite OK anymore?


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Received on 2011-12-10 19:00:18

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