Re: CIA old/new?

From: Segher Boessenkool <*segher_at_kernel.crashing.org*> Date: Mon, 4 Jan 2021 11:17:07 -0600 Message-ID: <20210104171707.GE30983_at_gate.crashing.org> · segher_at_kernel.crashing.org

On Mon, Jan 04, 2021 at 05:54:59PM +0100, Gerrit Heitsch wrote:
> On 1/4/21 5:19 PM, Segher Boessenkool wrote:
> >On Sun, Jan 03, 2021 at 09:45:39PM +0100, groepaz_at_gmx.net wrote:
> >>Not every detail in the design is clocked, some delays just happen 
> >>because of
> >>gate propagation delays - and when the process changes, those delays may
> >>change as well.
> >
> >Yup, exactly.
> >
> >>The well known "grey dot" the new VICII produces are related
> >>to exactly the same thing.
> >
> >But this isn't true at all.  You get the grey dot if *external* timing
> >is off!  The difference isn't between VIC-II versions, the difference is
> >between boards (and what PLA or PLA replacement is used on that).
> 
> So a 856x VIC II on an old board like a 250407 shouldn't show grey dots?

It depends on what the timing would end up as (it still is a race
condition), but yup, it will probably work.  (The first half pixel will
have the old colour, not light grey).

Segher