Search found 14 matches

by meynaf
Mon Aug 08, 2016 9:14 pm
Forum: AY sound chip
Topic: Oric's 8912 volume scale
Replies: 35
Views: 24280

Re: Oric's 8912 volume scale

I have a friend that could explain why emulation need some clever math for giving the correct sound, I haven't seen this video yet, I can ask him to make a simple text to explain why if some of you are interested! I already know why emulation needs some clever math. What i don't know is what this c...
by meynaf
Mon Aug 08, 2016 10:06 am
Forum: AY sound chip
Topic: Oric's 8912 volume scale
Replies: 35
Views: 24280

Re: Oric's 8912 volume scale

The links he gives at the very end of the video are also useful. Next time someone pretends the oric (or whatever ym emulation program) plays the ST tunes identical i'll send him to sndhrecord.atari.org for a comparison :p Btw. Does someone know if there is a site with oric tune recordings ? Having ...
by meynaf
Thu Jul 28, 2016 8:14 am
Forum: AY sound chip
Topic: Oric's 8912 volume scale
Replies: 35
Views: 24280

Re: Oric's 8912 volume scale

But technically there is no differences between an Oric and an Atari ST, the channel mixing is done in the same way. Really, no. They're identical only on the paper. I heard the differences. If you look at a good YM emulator you will see that it doesn't do linear mixing. Rather, it uses levels meas...
by meynaf
Tue Jul 26, 2016 4:58 pm
Forum: AY sound chip
Topic: Oric's 8912 volume scale
Replies: 35
Views: 24280

Re: Oric's 8912 volume scale

If you are looking for emulating an GI/AY chip, you can look at that code: http://obex.parallax.com/object/153 It's not made for a classic CPU, but the assembly code is quite easy to read and really straight forward. I already have this kind of emulation stuff. What i want is oric specific differen...
by meynaf
Thu Jul 21, 2016 6:55 pm
Forum: AY sound chip
Topic: Oric's 8912 volume scale
Replies: 35
Views: 24280

Re: Oric's 8912 volume scale

If the case is for emulation only, you can take a look in Oricutron and Euphoric sources. This kind of emulation takes a lot more cpu than what i intend to use. I prefer something simpler ; does not need to be perfect but must be realistic enough. I'm not writing an oric emulator, just some simple ...
by meynaf
Thu Jul 21, 2016 11:58 am
Forum: AY sound chip
Topic: Oric's 8912 volume scale
Replies: 35
Views: 24280

Re: Oric's 8912 volume scale

@meynaf : Where did you found the value 1V max output? In AY-3-8912.pdf is written "NORMALIZED voltage range" which is obvious different from the absolute 0..1V range. As said, i'm quite noob in electronics. I read "1V" in the manual, so for me a single channel outputted max 1V. I'm just a programm...
by meynaf
Wed Jul 20, 2016 6:04 pm
Forum: AY sound chip
Topic: Oric's 8912 volume scale
Replies: 35
Views: 24280

Re: Oric's 8912 volume scale

(VoltageCHA + VoltageCHB + VoltageCHC) / 3 = TotalVoltage That's what i'm saying, it is a sum. Because it's the same thing as : VoltageCHA/3 + VoltageCHB/3 + VoltageCHC/3 = TotalVoltage But applying this formula in YM/GI emulation code is doomed to fail. There are other things at play. For the YM i...
by meynaf
Wed Jul 20, 2016 9:00 am
Forum: AY sound chip
Topic: Oric's 8912 volume scale
Replies: 35
Views: 24280

Re: Oric's 8912 volume scale

No it's not the same, channel A is outputing a 440Hz square wave for exemple, and B & C are forced at 1V, you will have a 1V (full scale) square wave. If B and C are forced at 0V (which is more likely IRL) it will oscillate between 0 and 0.3333V It's the same things as connecting AA battery in para...
by meynaf
Tue Jul 19, 2016 8:04 pm
Forum: AY sound chip
Topic: Oric's 8912 volume scale
Replies: 35
Views: 24280

Re: Oric's 8912 volume scale

The formula is (V1 + V2 + V3) / Number_Of_Source so here: (1+0+0)/3 = 0.33333V So in fact it's the same, but divided by 3 ? But then, it's like if a single channel can't output more than 0.33V by itself. The theory seems to say the waveforms should just get added together (averaged if you prefer), ...
by meynaf
Tue Jul 19, 2016 5:12 pm
Forum: AY sound chip
Topic: Oric's 8912 volume scale
Replies: 35
Views: 24280

Re: Oric's 8912 volume scale

Godzil wrote: mixing all the output together is not going you a maximum of 3V when all of the channel are at the highest voltage value, but at the highest that all of the three channel can output so about 1V
Then if one channel's output is 1V, the final output is 1V regardless of the two other channels ? :?
by meynaf
Tue Jul 19, 2016 2:31 pm
Forum: AY sound chip
Topic: Oric's 8912 volume scale
Replies: 35
Views: 24280

Re: Oric's 8912 volume scale

So yes, I have first hand confirmation that some of the AY compatible chips do have linear volume output. Didn't know that. Yet the one in the oric clearly doesn't have linear volume output, so it doesn't help with my problem... (But it explains why i've found some musics that sound much better wit...
by meynaf
Tue Jul 19, 2016 10:55 am
Forum: AY sound chip
Topic: Oric's 8912 volume scale
Replies: 35
Views: 24280

Re: Oric's 8912 volume scale

Well, I've been using the Atari ST for quite a while, and the musics I converted were almost all musics I did listen to a lot on the Atari :) Some musics are quite tolerant ;) So on many musics you won't be able to tell the difference. Got some emulator source which said basically this : on the ST ...
by meynaf
Tue Jul 19, 2016 7:49 am
Forum: AY sound chip
Topic: Oric's 8912 volume scale
Replies: 35
Views: 24280

Re: Oric's 8912 volume scale

Yeah sure, you convert things, but you're never sure they're really played like they ought to be. Ym tunes are usually much louder than oric tunes ; oric is normally around 9 in volume while ym's evolve around 12-14. So ym tunes should scare you away if you play them with the same volume level. Noti...
by meynaf
Mon Jul 18, 2016 7:02 pm
Forum: AY sound chip
Topic: Oric's 8912 volume scale
Replies: 35
Views: 24280

Oric's 8912 volume scale

Hi, i'm new here. The question is related to audio output volumes. Normally they are logarithmic so that +2 volume equals *2 amplitude. Normally channels are mixed linearly so two channels playing the same sound equals twice the amplitude. All similar chips (AY 8910, YM 2149) should behave the same....