On Thu, Nov 07, 2019 at 10:36:00AM +0100, silverdr_at_wfmh.org.pl wrote: > > On 2019-11-07, at 09:33, Segher Boessenkool <segher_at_kernel.crashing.org> wrote: > >>>> And there are some icing on the cake too - with one command we can turn on/off the annoying HMOS VIC "sparkles" w/o modifications to the board for example as well as enable "Lumafix". This with jumper though :-) > >>> > >>> What does it do for the sparkles? > >> > >> but with a flip of a bit we add a tiny delay to the R/_W line, which > >> makes HMOS VIC output behave the same as NMOS one. > > > > What I meant to ask (and failed horribly at :-) ) is how do you do that? > > > > Perhaps I do just not know how this expansion works? I assumed you keep > > the original system (including ram, cpu, vic) intact, only adding some > > cartridge or other plug-in; but maybe you don't. > > CPU, RAM, etc. remains untouched. The expansion comes between the VIC and its socket. This means we have all VIC signals and we buffer/process the required ones. R/_W is one of those, which we have to handle anyway because we need it to communicate with the VIC. From there it was only a small step to have the sparkles annoyance fixed at will. Ah I see, a man-in-the-middle design, so this is straightforward to do. Thanks for the explanation! SegherReceived on 2020-05-29 23:29:57
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