Search found 45 matches

by LightStruk
Mon Mar 28, 2016 1:32 pm
Forum: NESdev
Topic: Reasonable implementation of PCM
Replies: 20
Views: 7070

Re: Reasonable implementation of PCM

Have you considered using MMC5's raw PCM channel instead? Full 8-bit audio; far better quality than the built-in DPCM's 7 bits Write mode: Write the 8-bit sample directly to $5011, just like writing a 7-bit sample to $4011 Read mode: simply read any address between $8000-$BFFF, and that byte is auto...
by LightStruk
Mon Feb 15, 2016 2:16 pm
Forum: NES Hardware and Flash Equipment
Topic: My home-made PAL/NTSC *4 CPU* famiclone 60/72pin cart
Replies: 6
Views: 5747

Re: My home-made PAL/NTSC *4 CPU* famiclone 60/72pin cart

Very impressive. Home etching is intimidating, so kudos on making it work. Having both the NTSC and PAL CPUs and PPUs on the same 2 layer board must have been a challenge to route! I notice you simply use pins sticking out of the board for your NES controller sockets. In case you're looking for actu...
by LightStruk
Thu Feb 11, 2016 1:50 pm
Forum: NES Graphics
Topic: Graphics Challenge: Color-reduce this parrot
Replies: 33
Views: 18315

Re: Graphics Challenge: Color-reduce this parrot

tepples, was black the best background color for this image? What if you used red or orange instead? It looks like you re-used a color between the first two palettes - what if that were the background instead?
by LightStruk
Tue Jan 12, 2016 9:17 am
Forum: NES Graphics
Topic: Yet yet another NES palette capture
Replies: 13
Views: 10907

Re: Yet yet another NES palette capture

I thought YIQ was just a 33 degree phase rotation of YUV I think that's right. I guess the same RGB primaries are plugged into the YUV->RGB equation as the YIQ->RGB equation, so it's just a question of whether AviSynth lets you change the primaries. ("c.ConvertToRGB()" almost certainly defaults to ...
by LightStruk
Tue Jan 12, 2016 8:59 am
Forum: NES Graphics
Topic: Yet yet another NES palette capture
Replies: 13
Views: 10907

Re: Yet yet another NES palette capture

With the capture format set to YUY2, there are two colorspace conversions that led to the PNGs you posted: one from YIQ to YUV (in the capture hardware), and then another from YUV to RGB when the image was exported to RGB (in AviSynth, probably). The chroma subsampling in YUY2 (4:2:2) doesn't affect...
by LightStruk
Tue Jan 05, 2016 12:52 pm
Forum: NES Hardware and Flash Equipment
Topic: FDSemu - New FDS drive emulator, with menu and large flash
Replies: 59
Views: 44435

Re: FDSemu - New FDS drive emulator, with menu and large fla

Impressive work. Still, it's frustrating that one needs a FDS RAM adapter to use it. The RAM adapter alone is ~$16 these days on eBay, so I guess that's not so bad. The only other option would be a flash cart like the PowerPak. Are there issues with the fidelity of the FDS implementation in the flas...
by LightStruk
Fri Jan 01, 2016 8:23 am
Forum: NES Graphics
Topic: A more accurate NES palette?
Replies: 61
Views: 75808

Re: A more accurate NES palette?

But I'm not really willing to go to quite that much bother to improve this palette; in my opinion, it's already as close to 'perfect' as one can get. :p …At least, for an NTSC palette. Nor should you. If there's anything these palette threads have taught me, it's that there are so many things that ...
by LightStruk
Thu Dec 31, 2015 1:14 pm
Forum: NES Graphics
Topic: A more accurate NES palette?
Replies: 61
Views: 75808

Re: A more accurate NES palette?

I'd say, "I can confirm this on my own TV," but TVs can differ greatly even between identical models from the same brand, and some people have their TV's tints set differently as well, sooo… Sure, these are analog systems we're talking about, so that's why I'm wondering about calibration. But that ...
by LightStruk
Wed Dec 30, 2015 1:00 pm
Forum: NES Graphics
Topic: A more accurate NES palette?
Replies: 61
Views: 75808

Re: A more accurate NES palette?

Something that has always seemed weird to me for as long as I've used NES emulators - was the sky in SMB1 and Zelda 2 really this purple? smb1title.png zelda2ruto.png I no longer have a real NES console or a CRT TV, so I can't check for myself. Assuming that this palette matches the behavior of corr...
by LightStruk
Sat Mar 08, 2014 8:17 am
Forum: NESemdev
Topic: Reverse-engineered FDS BIOS?
Replies: 5
Views: 2644

Reverse-engineered FDS BIOS?

Has anyone ever attempted to make a replacement FDS BIOS? Using the dumped real FDS BIOS obviously works for emulation, but that dump is still a copyrighted work. The replacement BIOS wouldn't need to be a drop-in replacement for the real thing on real hardware. It would only need to work well enoug...
by LightStruk
Sat May 04, 2013 8:56 pm
Forum: NESemdev
Topic: Passing blargg's 10-stack.nes test
Replies: 10
Views: 6694

Re: Passing blargg's 10-stack.nes test

That was it - I was generating NMIs when I should not have been. My half-baked PPU logic was worse than no PPU at all. :D Now my emulator passes all of your instr_tests!

Thank you so much for your help!
by LightStruk
Sat May 04, 2013 7:10 pm
Forum: NESemdev
Topic: Passing blargg's 10-stack.nes test
Replies: 10
Views: 6694

Re: Passing blargg's 10-stack.nes test

One more thing - I downloaded instr_test-v3 today, and despite passing everything in nes_instr_test except test 10, I get failures all OVER the place with instr_test-v3. Not every instruction, but many of them. For example, the failures for tests 1 and 2: instr_test-v3/rom_singles/01-implied.nes: 0A...
by LightStruk
Sat May 04, 2013 7:03 pm
Forum: NESemdev
Topic: Passing blargg's 10-stack.nes test
Replies: 10
Views: 6694

Re: Passing blargg's 10-stack.nes test

PHP:

Code: Select all

PushStack(Registers.p.raw | 0x10); // PHP pushes the flags with b set to 1
by LightStruk
Sat May 04, 2013 10:45 am
Forum: NESemdev
Topic: Passing blargg's 10-stack.nes test
Replies: 10
Views: 6694

Re: Passing blargg's 10-stack.nes test

Thank you for helping me investigate this! With regard to wrapping, I use a uint8_t to store the stack pointer, which I post-decrement on Push and pre-increment on Pop: inline void CPU::PushStack(uint8_t value) { Write(value, STACK + Registers.sp); --Registers.sp; } inline uint8_t CPU::PopStack() { ...
by LightStruk
Sat May 04, 2013 8:52 am
Forum: NESemdev
Topic: Passing blargg's 10-stack.nes test
Replies: 10
Views: 6694

Passing blargg's 10-stack.nes test

I've been scratching my head over how my emulator can completely pass all of blargg's nes_instr_test ROMs except for the stack test ROM. The message at $6004 says 08 PHP 68 PLA 28 PLP 9A TXS BA TSX 10-stack Failed My emulator also produces output on nestest.nes identical to the "golden" Nintendulato...