Re: more VIC-II musings

From: groepaz_at_gmx.net
Date: Mon, 13 Jan 2020 21:04:00 +0100
Message-ID: <1784529.Hl66XcICjp_at_rakete>
Am Montag, 13. Januar 2020, 20:55:50 CET schrieb Michiel Boland:
> Hi. Not sure if this has been mentioned already, but there is a bug in the
> VIC-II chip where it will simultaneously shift a sprite shift register and
> attempt to load it with a new value at the same time, for the duration of
> one pixel. This introduces some interesting phase-of-the-moon bugs in
> combination with multi-color mode. At least, that what I think is going on.
>
> https://youtu.be/BN8LQz7aBLg
>
> As an aside, there appears to be some work here and there of people who have
> reverse-engineered, or have tried to reverse engineer the VIC-II chip based
> off of die shots. But there does not appear to be anything definitive
> online (a la visual6502), or it was once there but has since disappeared.
> Or maybe I am looking in the wrong places. What is there to be found
> regarding this? (So I don't have to reinvent the wheel. :)

i think the most work was done by tlr and nojoopa when x64sc was implemented.
i dont think any details from die-shot reversing where posted anywhere. (i am
not aware of any such work either... except for one guy (androsid) on the
german forum64 - he seems to be working on it, but didnt post any details yet
either)


--

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I do not believe in a personal God and I have never denied this but have
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<Albert Einstein>
Received on 2020-05-30 00:16:43

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