Some accuracy tests on Famicom AV

Discuss emulation of the Nintendo Entertainment System and Famicom.

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Eugene.S
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Some accuracy tests on Famicom AV

Post by Eugene.S »

Hi, nesdev.
I've just got Famicom AV with Everdrive N8 and capture device.
So, i can run accuracy tests if you need it.

Let's go.
1) "NEStress - I/O ports", "count_errors" and "count_errors_fast" test
on Original FC AV with "dog-bone" controller and with pirate controller:
http://wiki.nesdev.com/w/index.php/Stan ... il_Details
http://hwm.us.to/famimusic/Forum/hardwa ... rs_test.7z
puNES can emulate it correctly. But why official controllers have these errors?

2) scanline/scanline:
http://hwm.us.to/famimusic/Forum/hardwa ... erlace.avi
http://hwm.us.to/famimusic/Forum/hardwa ... umeTFF.avi
Last edited by Eugene.S on Wed Sep 21, 2016 4:41 pm, edited 2 times in total.
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feos
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Re: Some accuracy tests on Famicom AV

Post by feos »

Tha main quesiton is, WTF is going on with these controller tests? They count "errors" and "conflicts", what does it mean? Especially when it catches zero for pirate controller, and a whole bunch for official one? What exactly are we measuring here?
lidnariq
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Re: Some accuracy tests on Famicom AV

Post by lidnariq »

"0" for the pirate controller almost certainly means that the shift register in the pirate controller returns 0s for the 9th and later reads, unlike 1s as on the official NES/FC controller.
Alyosha_TAS
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Re: Some accuracy tests on Famicom AV

Post by Alyosha_TAS »

Hi,

I have hex editted the scanline test a bit to use greyscale toggling in the first test instead of background rendering. I would be very interested seeing the results if you would be able to do it.


It is attached.
Thanks!
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scanline.nes
For greyscale testing
(24.02 KiB) Downloaded 214 times
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Eugene.S
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Re: Some accuracy tests on Famicom AV

Post by Eugene.S »

Last edited by Eugene.S on Wed Sep 21, 2016 4:42 pm, edited 1 time in total.
Alyosha_TAS
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Re: Some accuracy tests on Famicom AV

Post by Alyosha_TAS »

Thanks for running the test. Is that how the screen really looked though? Or is something just up with the video?

If that blue color isn't getting captured very well I can pick a different one. There are a couple more similar tests I'm thinking about so let me know if I need to change it.
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Eugene.S
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Re: Some accuracy tests on Famicom AV

Post by Eugene.S »

Last edited by Eugene.S on Wed Sep 21, 2016 4:43 pm, edited 1 time in total.
Alyosha_TAS
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Re: Some accuracy tests on Famicom AV

Post by Alyosha_TAS »

Cool thanks. Looks like the blue definitely messed with the capture a bit.

If you don't mind, I have just one more scanline variant I would like tested. This one toggles greyscale in the exact same places that the original scanline test does. So if there is any difference between the results of this test and the original scaline test, it will confirm that greyscale is checked later down the pipeline then other pixel properties.

Thanks!
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scanline.nes
(24.02 KiB) Downloaded 186 times
Alyosha_TAS
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Re: Some accuracy tests on Famicom AV

Post by Alyosha_TAS »

Awesome! Thanks again for running those. So looking at the V2 test and comparing to the original, this confirms my suspicion that the greyscale check happens 2 pixels later then the toggle background check. The only thing I changed is which one is toggled, and the results are evident that V2 takes effect 2 pixels to the left on the screen. This finally solves the mystery of the NMI_sync test :D

Currently i don't know why the lines in the sceond test are flickering though, something else to investigate at some point.
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Quietust
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Re: Some accuracy tests on Famicom AV

Post by Quietust »

Also consider that the scanline.nes jitter may be sensitive to CPU/PPU alignment - the last time I ran it on a CopyNES, there was some variation between resets.
Quietust, QMT Productions
P.S. If you don't get this note, let me know and I'll write you another.
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Eugene.S
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Re: Some accuracy tests on Famicom AV

Post by Eugene.S »

Something that would immediately help with determining if BizHawk's implementation of this correct is running
dmc_dma_during_read4\dma_4016_read with different buttons held down on the controller.
Of particular interest would be results from holding down A, B, A+B
Tested on original FC AV dogbone controller:

http://hwm.us.to/famimusic/Forum/hardwa ... g_read.zip

no button pressed, A hold down
B hold down, A+B hold down

P.S: This test hangs for me on pirate controller.
Sour
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Re: Some accuracy tests on Famicom AV

Post by Sour »

Does the scanline test actually give a perfect picture on the original NES? Can it give the same output as shown in Eugene's video based on CPU/PPU alignment?

I always assumed the scanline rom failed on Mesen due to the flashing I get on the first test, but I am getting the exact same pattern as Eugene's video (although the result for the 2nd test differs in my case - does the 2nd test ever flash like this on a NES?). Nestopia UE also displays the exact same pattern, but Nintendulator's and puNES's patterns are slightly different.
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Eugene.S
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Re: Some accuracy tests on Famicom AV

Post by Eugene.S »

According to this issue:
https://github.com/rdanbrook/nestopia/issues/209

I ran turbocheck test on old (middle 90-s) and new (aliexpress) pirate controllers and it give different speed results.

Can anyone run this test on official NES MAX controller?
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pirate_controllers_turbo_test.7z
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