Lynx sound buffer

[obschan]

Hello !

 

I'm new in Lynx world.

 

I was wondering how the sound data are stored in the lynx RAM buffer.

I thought it was an 8 bits 11KHz PCM format, but seems no.

 

Is anybody know the answer to this question ?

 

Thanks in advance.

 

(Sorry for my poor english)

[Harry_Dodgson]

The Lynx is build-it-yourself sound. It makes it more flexible than a fixed format, but a bit more painful to program. And the only RAM buffer is one you setup yourself (as well) and feed to the sound registers via interrupt.

[sage]

I was wondering how the sound data are stored in the lynx RAM buffer.

I thought it was an  8 bits 11KHz PCM format, but seems no.

996784[/snapback]

 

As Harry already mentioned, its up to the user to feed the sound registers. This means its up to you if you use 8bit signed raw data or some packed data. Also the frequency can be choosen freely, by setting the interrupt to the desired frequency. (Unpacking in interrupt is possible but maybe abit slow)

[obschan]

Thank you for these quick answers.

 

Sorry for my ignorance.

Ok, seems I need to do more of my Lynx homework

 

Thanks again.

[Lamer Deluxe tm]

One idea that some games use is to utilise the horizontal blanking interrupt to feed the audio system with digital samples. Depending on the display frequency this gives you a samplerate of about 6KHz.

 

The advantage is that you won't have a seperate audio interrupt slowing the system down if you're already using the horizontal blanking interrupt for something. Roadblasters does it this way, for example.

 

What's very cool about the Lynx II is that it gives you full stereo panning for each of the four voices.

[philipj]

That's definetly one system I'd like to create a better music software for. I forget the location of the link where you can download "PDF" on subjects about the Lynx, but it's here somewhere. I think Carl Forhan had something to do with posting it, but it's definetly whorth reading... You'll find a lot good stuff the Lynx sound system in the PDF's... It's a big file size though.

[jum]

I used 4-bit samples at about 3khz for my "Bezerk" clone.

 

Check out the source code to see how it worked:

 

http://jum.pdroms.de/

 

(Look in the Lynx section for Befok source code).

 

- jum

[Matthias]

Hello!

 

That's definetly one system I'd like to create a better music software for.  I forget the location of the link where you can download "PDF" on subjects about the Lynx, but it's here somewhere.  I think Carl Forhan had something to do with posting it, but it's definetly whorth reading... You'll find a lot good stuff the Lynx sound system in the PDF's... It's a big file size though.

998401[/snapback]

 

Do you mean the Lynx-Developer docs?

You could find them here:

Lynx developer-docs

 

 

But AFAIK there is also the special, Amiga-based sound-compoing software Epyx provided.

 

 

Regards

Matthias

[+karri]

But AFAIK there is also the special, Amiga-based sound-compoing software Epyx provided.

999632[/snapback]

 

And don't forget my humble Lynx ABC music attempt to tame the 22 cent audio hardware that the Lynx has.

 

My module has advanced a lot recently and I also have a tool for converting any Midi files to the Lynx. The Lynx has only 4 independent sound generators so you have to choose 4 voices to play from a multitimbral Midi tune.

 

So if someone is interested in helping I could use your time and energy to experiment with instrument settings.

 

I already have a Lynx tool for trying out unique non-clipping waveforms on the real hardware. The Lynx is capable of producing 6185 different unique binary patterns. Most of these patterns are unusable for instrument sounds because they contain an odd number of ones and zeros so the integrator will cause the sound to clip after a while and this produces a bopping engine-sound. But I have produced a tool that will cycle through the "good" sounds only and the tool will also auto-adjust the volume settings so that the sound does not get clipped.

 

What still remains is to listen through several hundreds of these "good" sounds and experiment with attack and decay settings to find sounds similar to Sax, Trombone, Piano etc. You may also have to rewrite the attack/decay code to make proper sounds. Once these are found I would like to include the instrument settings in the music driver. Then it is easy to pick good instruments automatically during the Midi conversion. And this would help a lot with creating good moods for games.

 

The reason for not using the sample-technique is that the Lynx audio hardware runs in parallell with the CPU. So it takes very little CPU resources compared to samples.

 

--

Karri