Am Donnerstag, 7. Januar 2021, 18:54:12 CET schrieb silverdr_at_wfmh.org.pl: > > On 2021-01-07, at 04:12, Segher Boessenkool <segher_at_kernel.crashing.org> wrote: > >>> I assume this is the line that goes from CS to the "VIC" pin on the new > >>> PLA on a 250469? Trace cut and put cap between them? > >> > >> No. You'd have to put a cap between the /CS on the VIC and GND. > > > > Yup. Just a low-pass filter, used as a crappy delay. I would put it > > close to the pin on the VIC, but that may not matter much. > > > >> You shouldn't do that though. > > > > We only did it to show what causes the problem, yup. > > As I mentioned already in this thread - only (some) of the HMOS-II chips > expose the problem. Among those which do, it may depend on the chip's > temperature (problem fades with temperature rising). OTOH no single NMOS > based VIC expose the issue even with the same board timing. Yes, you can > patch the _CS line with a cap and crudely work the problem around this way > but I say it once again: with the very same _CS timing no NMOS VIC produces > the annoying sparkles. So it is up to whoever reads this to decide whether > this is a bug of the board/PLA/replacement or the actual HMOS-II VIC. For > me it's the latter. yep. can easily be checked on a board that supports both. -- http://hitmen.eu http://ar.pokefinder.org http://vice-emu.sourceforge.net http://magicdisk.untergrund.net Der Drache lehrt: Wer hoch steigen will, muss es gegen den Wind tun. <Chinesische Weisheit>Received on 2021-01-07 20:00:02
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