RE: [stella] WSYNC again (3 or 5 clocks?)

Subject: RE: [stella] WSYNC again (3 or 5 clocks?)
From: "John Saeger" <john@xxxxxxxxxxx>
Date: Sat, 29 Jul 2000 10:45:04 -0700
Thomas Jentzsch wrote:

> If i'm not completely wrong, this little experiment should show,
> that WSYNC only needs 3(!) clocks.
> Did anybody try a well timed routine and tested WSYNC? Are you
> absolutely sure?? If yes, where
> am i wrong?

Yes I have done this.  :-)  If you think about it it makes sense since a
store to page zero takes 3 cycles.  And storing to WSYNC essentially turns
off the processor until the next scanline comes on.  The trick for getting
the emulator to work is doing exactly the right thing when the STA WSYNC
comes very close to the end of the scanline, and I have tested all of these
cases very carefully.  If you are really interested let me know and I will
send you the programs I used to test it with.


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