Search found 39 matches

by ap9
Wed Nov 22, 2017 12:08 am
Forum: NES Music
Topic: Did an orginal, unmodded Famicom sound like this? (Samples)
Replies: 13
Views: 9915

Re: Did an orginal, unmodded Famicom sound like this? (Sampl

I've attached the source code and ROM file of a pink noise generator, which I approximately verified as such by generating a wav file in FCEUX for Windows and analyzing it in Audacity. It also has a sine sweep generator; can anyone explain why it sounds so aliased? The output is aliased mostly part...
by ap9
Wed Oct 18, 2017 12:29 am
Forum: NES Music
Topic: New VRC7 patch set
Replies: 28
Views: 34798

Re: New VRC7 patch set

I found a few sustain, decay and release values are slightly off according to the waveforms in the patch test recording (internal patch first, approximated second). The set is very close, of course— I found only three instances one point off. It was in the process of updating my emulator that I made...
by ap9
Thu Oct 05, 2017 7:38 pm
Forum: General Stuff
Topic: Digital Foundry Retro Doom port comparison
Replies: 41
Views: 15040

Re: Digital Foundry Retro Doom port comparison

Possibly. But SA-1 is expensive, and few emulators support it. What? Every emulator supports the SA-1. It's not accurate, but it's there. At the time I was reading up on more exotic implementations for expansion chips (e.g., non-PC emulators). I should've used the word 'fewer' in regards to the gen...
by ap9
Tue Oct 03, 2017 3:41 pm
Forum: General Stuff
Topic: Digital Foundry Retro Doom port comparison
Replies: 41
Views: 15040

Re: Digital Foundry Retro Doom port comparison

Possibly. But SA-1 is expensive, and few emulators support it.
by ap9
Tue Oct 03, 2017 3:47 am
Forum: General Stuff
Topic: Digital Foundry Retro Doom port comparison
Replies: 41
Views: 15040

Re: Digital Foundry Retro Doom port comparison

I had somehow gotten the impression that Doom drew the walls in horizontal strips. If it really draws them in vertical strips (which honestly makes a lot more sense), then either the SNES version uses a different technique or it's wasting a lot of RAM bandwidth. It's possible the mosaic trick could...
by ap9
Sun Sep 10, 2017 4:27 am
Forum: General Stuff
Topic: Is there any equation of converting PCM to FM?
Replies: 20
Views: 6313

Re: Is there any equation of converting PCM to FM?

It is possible to develop a program to produce an FM patch from a short PCM sequence. The result would be an approximation — a simpler waveform from a sound. Any further detail would require, in theory, wave sampling — a driver (using the CPU) to render a sequence of FM waves to come closer to the o...
by ap9
Thu Aug 10, 2017 7:49 pm
Forum: NES Music
Topic: More NSF Requests
Replies: 3027
Views: 1096970

Re: More NSF Requests

rainwarrior wrote:What are the other NSFe players? I only know of NotSoFatso.
Mednafen and Mesen support NSFe. (Both have their share of limitations and bugs, of course.)
by ap9
Sat Jul 15, 2017 11:14 pm
Forum: NES Music
Topic: Famicompo Pico returns on 2017 June 15!
Replies: 48
Views: 18397

Re: Famicompo Pico returns on 2017 June 15!

Game_Music_Emu doesn't support the MMC5, FDS or VRC7 expansion audio chips or the 5B noise or envelope channels. FCEUX (and by extension Mednafen) doesn't support alternative PLAY rates or the 5B noise/envelope. Nestopia doesn't support NSFs at all. Which means the last two editions of Famicompo co...
by ap9
Fri Jun 30, 2017 2:21 am
Forum: NES Graphics
Topic: Is it possible to add new colors to the palette?
Replies: 24
Views: 12388

Re: Is it possible to add new colors to the palette?

According to the VT03 documentation PDF, the XRC 1 mode palette is divided into four 12x2 entry regions (plus mirrored transparent #0) across 3F00-3F7F, combined with parallel 3F80-3FFF for 12 bits per entry (4 bits per L, S and H). (3,500 color selection?) Up to 121 colors can be represented at onc...
by ap9
Tue Jun 27, 2017 12:42 am
Forum: NES Music
Topic: More NSF Requests
Replies: 3027
Views: 1096970

Re: More NSF Requests

Mahjong Club - Nagatacho Sousaisen (SFX) crashes or winds up at a bad address when a PCM sound effect completes. (Some players handle it better.)
by ap9
Sat Jun 24, 2017 10:53 pm
Forum: NES Music
Topic: More NSF Requests
Replies: 3027
Views: 1096970

Re: More NSF Requests

Much better in repeat, but still not quite fixed. If you restart track 1 of Battletoads repeatedly you'll find the timing wobbles a bit with each playback, sometimes by quite a lot. Yeah, the timing/tempo is slightly inconsistent (in Nintendulator, but fine in others). An improvement nonetheless. :...
by ap9
Fri Jun 23, 2017 10:57 pm
Forum: NES Music
Topic: More NSF Requests
Replies: 3027
Views: 1096970

Re: More NSF Requests

Well drat. I pass all the test ROMs for the IRQ flag so it looks like this one's going to be a headache. Definitely seems buggy that these two NSFs rips — Skate or Die 2 and Battletoads — don't work as intended in a more complete implementation of the APU, but work when turning off a few lines of c...
by ap9
Thu Jun 22, 2017 2:15 am
Forum: NESemdev
Topic: NES 2.0 expansion for maskROM data
Replies: 44
Views: 15451

Re: NES 2.0 expansion for maskROM data

Oh, tangenting all the way back to your comment about City Fighter... it really looks like it's just a 4-bit DAC in the cartridge? The rest of the emulator code doesn't support any kind of hardware decompression or hardware controlled FIFO, and yet the in-game audio still plays with just that simpl...
by ap9
Mon Jun 12, 2017 2:12 am
Forum: NESdev
Topic: Why only 52 colors instead of 256?
Replies: 63
Views: 12167

Re: Why only 52 colors instead of 256?

According to this website (or The History Of Nintendo vol. 3), Shigeru Miyamoto himself designed the palette and its color count. "Enough color to make something nice but not a lot to avoid the high price of production. Each decision about a color will influence Game’s apparences on this console. At...
by ap9
Sat Jun 10, 2017 5:15 am
Forum: NESdev
Topic: Why only 52 colors instead of 256?
Replies: 63
Views: 12167

Re: Why only 52 colors instead of 256?

the PPU had only 32 palette entries Actually, 28 palette entries, but only 25 can be used normally, the remaining 3 can only be displayed if rendering is turned off. Yes, forgot that only 28 entries actually exist in palette RAM. 7 in 32 mirror entry #0 -- 3 of which won't render because all #0 pix...