Search found 4 matches

by zzzz898
Sun Oct 07, 2018 9:37 am
Forum: NESemdev
Topic: Sprite evaluation timing
Replies: 4
Views: 7484

Re: Sprite evaluation timing

Yes, that's what I meant, thanks :)
by zzzz898
Thu Oct 04, 2018 12:09 am
Forum: NESemdev
Topic: Sprite evaluation timing
Replies: 4
Views: 7484

Re: Sprite evaluation timing

Well, now I'm confused. The way I had it setup didn't work (step 1 and step 2 happen on different cycles): 1. fetch data from OAM 2. step 1 - sprite not in range 3. fetch data from OAM 3. step 2 - go back to step 1 There is no way you can scan through 64 different sprites, if 1 of them takes 4 cycle...
by zzzz898
Tue Sep 11, 2018 9:03 am
Forum: NESemdev
Topic: Sprite evaluation timing
Replies: 4
Views: 7484

Sprite evaluation timing

I'm trying to figure out a good way of programming the PPU sprite evaluation state machine, but the nesdev page is a little unclear to me. n even cycles, data is written to secondary OAM (unless secondary OAM is full, in which case it will read the value in secondary OAM instead) 1. Starting at n = ...
by zzzz898
Mon Aug 20, 2018 1:33 am
Forum: NESemdev
Topic: Emulator failing ppu_vbl_nmi test #2
Replies: 2
Views: 5639

Re: Emulator failing ppu_vbl_nmi test #2

I'm trying to fix the exact same bug right now in my emu.
Some info: check out "VBL FLag Timing" at this page http://wiki.nesdev.com/w/index.php/PPU_frame_timing