Blargg apu_tes.nes 2-len_table failed test 2 of 8

Discuss emulation of the Nintendo Entertainment System and Famicom.

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colinvella
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Joined: Sun Jun 05, 2016 1:41 pm

Blargg apu_tes.nes 2-len_table failed test 2 of 8

Post by colinvella »

Dear all,

I was wondering if anyone had issues with the length table tests within Blargg's apu_test NES rom. My actual length table seems to be correct but perhaps the problem is a secondary one. Anyone care to share their experiences please? What should I look for?

Screenshot from my emulator (EmuNes)
Image

My length table array:

Code: Select all

        protected static readonly byte[] lengthTable = {
            10, 254, 20, 2, 40, 4, 80, 6, 160, 8, 60, 10, 14, 12, 26, 14,
            12, 16, 24, 18, 48, 20, 96, 22, 192, 24, 72, 26, 16, 28, 32, 30
        };
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aLaix
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Re: Blargg apu_tes.nes 2-len_table failed test 2 of 8

Post by aLaix »

Yeah i remember failing that test.
Basically you need to copy the values from the wiki. if those values doesn't make your emulator pass the test test, then something is wrong with your implementation. Log how the length counter is decremented and maybe you will find some hints there.
Myself I had A really difficult time with the APU documentation on the wiki, specially the frame counter info, i was about to make a suggestion to improve the documentation but then Disch did something even better.
viewtopic.php?f=3&t=13767&hilit=apu+pseudo
Whenever i have trouble implementing something APU related i check it. At least for me it's way clearer than the wiki.

Happy coding!
*** O-Nes-Sama emulator team ***
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