Re: VIC 26 Lines Bug - Truth or Legend ?

From: Christer Palm (
Date: 2001-08-19 15:20:41

Martijn van Buul wrote:
> Marko Mäkelä wrote:
> > The VIC is based on NMOS technology.  Its electric power consumption (and
> > thermal power dissipation) are rather independent of the clock frequency.
> Yes, but in this case, you're not overclocking it, you're generating an
> illegal situation, quite possibly sending internal state machines into
> states which wouldn't have been reached in normal use. That's something
> different.
> Re 26 lines bug: I was referring to the Anime-Tion demo released at the
> Flag2000 party. MagerValp had a few words to say about that way. See
> the subthread of '6510 and 8500 differences' from early aug last
> year on this list.

I went back and checked that old thread. In one of the messages,
MagerValp presents a rough explanation of how the 26-line effect works
[]. Does
anyone have any pointers to the details around it (i.e. the exact timing
required, etc.)?

Enough should be known about the internals of the VIC-II at this time to
be able to come up with a reasonable explanation of what's going on at
the logic level here. That will also likely provide some additional
clues to further enhance the understanding of the VIC-II internal
design, which would provide some further facts in this discussion as
well as beeing of benefit to emulator developers, of course.

Christer Palm

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