Search found 7 matches
- Fri Mar 12, 2010 8:28 pm
- Forum: Regen
- Topic: FM Timer B bug + VDP vertical scrolling bug
- Replies: 6
- Views: 20446
Re: FM Timer B bug + VDP vertical scrolling bug
After some investigation, I figured the problem came from Timer B counter not being loaded properly, in my case because I was doing this to detect Timer B LOAD bit changes (FM register 0x27): if ((v&2) & !(ym2612.OPN.ST.mode&2)) ym2612.OPN.ST.TBC = ym2612.OPN.ST.TBL; I'm surprised your compiler did...
- Tue Feb 23, 2010 2:26 pm
- Forum: Video Display Processor
- Topic: Color counts per screen
- Replies: 137
- Views: 94701
BTW, I play with your NTSC filter on my RPTV at all times. Would you consider a comparison between raw emulator output color counts, the NTSC filter's, and Composite useful in any way? Maybe for the NES one. The SNES one reduces to 13-bit RGB before filtering. The Genesis one isn't very accurate, s...
- Tue Feb 23, 2010 5:43 am
- Forum: Video Display Processor
- Topic: Color counts per screen
- Replies: 137
- Views: 94701
One thing is that the Genesis pixel rate is slightly less than twice the color carrier frequency, so the color fringes do a rainbow as you go horizontally across the screen. For example, a simple black and white alternative vertical pattern will generate a rainbow. On the other hand, the SNES pixel ...
- Mon Feb 22, 2010 11:21 pm
- Forum: Sound
- Topic: New Documentation: An authoritative reference on the YM2612
- Replies: 865
- Views: 2478350
Well, shouldn't we just apply a limit like it was done in the original core ? By doing this, you are reducing FM output level (relative to PSG)... I think it's not very common that all channels are set to max, hence why a limiter was used but I wonder which solution is best. It's definitely rare, o...
- Mon Feb 22, 2010 10:52 am
- Forum: Sound
- Topic: New Documentation: An authoritative reference on the YM2612
- Replies: 865
- Views: 2478350
yeah, it seems I can't download them :wink: OK, try this mirror: genesis_recordings.zip Yeah. I just modified the channel muting mask from ~0 to ~((1 << 7) - 1). This preserves the sign bit. This was in the MAME version, where it applies this mask to each channel, sums them, divides by 2, then outp...
- Sat Feb 20, 2010 8:53 pm
- Forum: Sound
- Topic: New Documentation: An authoritative reference on the YM2612
- Replies: 865
- Views: 2478350
Here are some recordings (sorry for mp3, as I lack FLAC or anything modern): genesis_recordings.zip (2.6 MB; let me know if you have problems, as this host sucks) These are from the original Sega Genesis model, not a later one where sound is really crappy (on those, getting rings in Sonic for exampl...
- Sat Feb 20, 2010 6:39 am
- Forum: Sound
- Topic: New Documentation: An authoritative reference on the YM2612
- Replies: 865
- Views: 2478350
I was doing some testing today on a YM2612 emulator of the number of bits in the DAC. I believe it's a 7- or 8-bit DAC, that's time-division multiplexed (as the YM2612 Wikipedia page says). This means that the DAC really operates at 6 times the normal rate, or 1/24 the clock input. So for the Sega G...