S0.nes & NMI's

This is an archive of a topic from NESdev BBS, taken in mid-October 2019 before a server upgrade.
View original topic
S0.nes & NMI's
by on (#23696)
Hi all,

While running this demo on the real thing, is the black area on SP0 hits be constant or does it flicker?

I've observed that if I remove all $2002 read trickery (necessary to pass blargg's tests), it flickers no more..

Thx.

by on (#26195)
Under my emu conditions, the program seems to read VBL flag just one PPU clock before it being set, causing the setting itself being supressed.

Now, if I remove this supression, the "black bar" on sp0 hits flickers no more, but that obviously makes my emu to fail blargg's "2.vbl_timing
" test. Nestopia, on its side, passes every test, and still shows no flicker while running s0.nes.

Any clues?

Thx.

by on (#26196)
Was it my sprite 0 tester? I wrote that before much was known about the NES PPU.

by on (#26197)
It is the one by Damian Yerrick, "Sprite 0 Test", back to 2000. Did you write it? The point is that I dunno how it is expected to behave on the real deal.

by on (#26198)
I am Damian Yerrick.

And neither do I know how it works on an NES. All I had back then were NESticle, LoopyNES, and NESten.

by on (#26204)
Nice to meet you! :D And thanks for the info. ;)

M.

by on (#26210)
tepples wrote:
I am Damian Yerrick.

:shock:

I never knew that.

I like your NSF covers. :D