Search found 102 matches

by Alyosha_TAS
Sun Dec 16, 2018 11:58 am
Forum: GBDev
Topic: Halt check during halt
Replies: 1
Views: 6579

Halt check during halt

I've been working through Wilbert Pol's tests (which are variants of gekkio's with more variations) and so far for regular gameboy I am able to pass them all. But once I started working on GBC variants things started to not add up. The tests that didn't require a halt seem to work ok (except for edg...
by Alyosha_TAS
Sun Dec 16, 2018 11:45 am
Forum: NESemdev
Topic: 2nd2006_next_level test rom and extensions
Replies: 55
Views: 48379

Re: 2nd2006_next_level test rom and extensions

I think it would be good to modify the scroll test to check h-scroll as well. As in writing to the lower its of $2006 (and having some horizontal scroll apparent on screen of course.) It seems highly likely that the results will agree with the v-scroll ones, but having a dedicated test for would be ...
by Alyosha_TAS
Sat Dec 15, 2018 3:16 pm
Forum: NESemdev
Topic: 2nd2006_next_level test rom and extensions
Replies: 55
Views: 48379

Re: 2nd2006_next_level test rom and extensions

Can confirm that the scroll_v2 test powers up in the same state as I see on emulator, and that 'inc then &' correctly reproduces the results pixel for pixel.

Cool stuff!
by Alyosha_TAS
Fri Dec 14, 2018 3:02 pm
Forum: NESemdev
Topic: 2nd2006_next_level test rom and extensions
Replies: 55
Views: 48379

Re: 2nd2006_next_level test rom and extensions

The scrolling isn't happening because the sprite 0 hit isn't happening in VisualNES. Since Fiskbit's test doesn't rely on sprite 0, it might work, but requires user interaction. Oh, ok well that settles that. Thanks. @Sour: That's ok, I sure as heck can't fix it. It did perfectly duplicate 3 out of...
by Alyosha_TAS
Fri Dec 14, 2018 2:22 pm
Forum: NESemdev
Topic: 2nd2006_next_level test rom and extensions
Replies: 55
Views: 48379

Re: 2nd2006_next_level test rom and extensions

@lidnariq: you seem to be really good at understanding what the circuits in the ppu are supposed to do, do you have any idea why VisualNES is failing to scroll in the first version of the tests fiskbit posted? That error seems pretty serious and makes me a bit wary of VisualNES. @Eugene.S: well the ...
by Alyosha_TAS
Thu Dec 13, 2018 6:42 pm
Forum: NESemdev
Topic: 2nd2006_next_level test rom and extensions
Replies: 55
Views: 48379

Re: 2nd2006_next_level test rom and extensions

I think that the bus conflicts should only be in the "V" bits (0x7BE0) on dot 256, and should only be in the "H" bits (0x041F) in the middle of the scanline. The other bits look like they should be correctly copied from T to V. Yeah that definitely would make the most sense. Would you expect $2005 ...
by Alyosha_TAS
Thu Dec 13, 2018 5:26 pm
Forum: NESemdev
Topic: 2nd2006_next_level test rom and extensions
Replies: 55
Views: 48379

Re: 2nd2006_next_level test rom and extensions

I went over the frame by frame for scroll delay v1 test, and yeah it looks like the glitch is properly characterized by doing the v increment but then '&' the result with the latched value. My emulator gets exact results by doing this. This also still gives correct results for the original 2 tests. ...
by Alyosha_TAS
Wed Dec 12, 2018 4:47 pm
Forum: NESemdev
Topic: 2nd2006_next_level test rom and extensions
Replies: 55
Views: 48379

Re: 2nd2006_next_level test rom and extensions

Hmmm, this doesn't appear to be quite the same thing as the original tests. According to my emulator read out, the glitches that would result from the ppu scroll tests would be happening because of the v -> t operation at cycle 257. The previous tests were testing glitches at the increments at 256....
by Alyosha_TAS
Tue Dec 11, 2018 4:16 pm
Forum: NESemdev
Topic: 2nd2006_next_level test rom and extensions
Replies: 55
Views: 48379

Re: 2nd2006_next_level test rom and extensions

The second detail there seems to be on track to explain glitching when scrolling vertically in Zelda, which I've been working on recently. I discuss that in this thread , which includes test ROMs that can reproduce this on real hardware. The ill-timed writes cause some bits to get cleared, but not ...
by Alyosha_TAS
Mon Dec 10, 2018 7:26 pm
Forum: NESemdev
Topic: 2nd2006_next_level test rom and extensions
Replies: 55
Views: 48379

Re: 2nd2006_next_level test rom and extensions

ok, I can get the exact same behaviour as in the videos if I do the following things. -Delay latching of $2006 by 3 ppu cycles (this was already known and expected to be correct.) -Have a race condition between the h and v increments on cycle 256 and the latching from $2006 occurring on the same cyc...
by Alyosha_TAS
Sun Dec 09, 2018 6:33 pm
Forum: NESemdev
Topic: 2nd2006_next_level test rom and extensions
Replies: 55
Views: 48379

Re: 2nd2006_next_level test rom and extensions

These kinds of tests are kind of the last frontier for NES research, if you have any other ideas for similar tests please do put them together and hopefully we can get them run. The results so far are already very interesting.
by Alyosha_TAS
Sun Dec 09, 2018 4:09 pm
Forum: NESemdev
Topic: 2nd2006_next_level test rom and extensions
Replies: 55
Views: 48379

Re: 2nd2006_next_level test rom and extensions

So it looks like the automatic update done by the ppu is simple blocking the latching from $2006 from occurring altogether in the cases where the triangles turn blue. Not sure if it's losing a race condition or if it's intentional, but that's pretty clearly what's happening. Neat! It looks like matc...
by Alyosha_TAS
Sun Dec 09, 2018 1:56 pm
Forum: NESemdev
Topic: 2nd2006_next_level test rom and extensions
Replies: 55
Views: 48379

Re: 2nd2006_next_level test rom and extensions

Awesome thanks! That's really interesting. I didn't expect the text to go away sometimes. 0_0

Well, I know for certain now that my emulator is way off in dealing with these things, time to get at it.

(That video format is fine once I found the codec)
by Alyosha_TAS
Sun Dec 09, 2018 12:23 pm
Forum: NESemdev
Topic: 2nd2006_next_level test rom and extensions
Replies: 55
Views: 48379

Re: 2nd2006_next_level test rom and extensions

Cool thanks! That certainly raises more questions then it answers. Why do they turn blue? Curious. The other file should have 16k PRG and 8k CHR, so the header is wrong. Byte 4 should be 1 instead of 2. If you can get this version working and get some results for each of the 8 alignments that would ...
by Alyosha_TAS
Sun Dec 09, 2018 9:29 am
Forum: NESemdev
Topic: 2nd2006_next_level test rom and extensions
Replies: 55
Views: 48379

2nd2006_next_level test rom and extensions

I've been going over everything in my emulator again trying to see if there were any open ends or inconsistencies I could find. This test stands out as being pretty important but untested. Just as a refresher, this test was originally put out by fred in response to this thread. The idea is that latc...