Sound capabilities of the Firebee

[simonsunnyboy]

Which known Atari audio devices are available on the Firebee?
According to a Wiki atleast the YM2149? Is this correct?

How about STE compatible DMA audio or the Falcon Audio subsystem?

[Orion_]

I don't know about ym2149, but the Falcon DMA is fully working using xbios function !

[simonsunnyboy]

I have never used the Falcon XBIOS routines for audio sofar. Is there a guide or manual available about its capabilities beyond what I can find in tos.hyp?

[joska]

The Firebee has a YM that's fully (and from what I can tell perfectly) emulated in the FPGA. It also has STE DMA sound thanks to some software trickery (transparent to the user). There is no Falcon sound *hardware*, but there is XBIOS support for the AC97 soundchip. This XBIOS is GSXB compatible. See http://assemsoft.atari.org for docs on GSXB.

[simonsunnyboy]

Having the YM sounds great already

"Software" trickery for the STE DMA sound? Does it intercept reads and writes to the associated hardware registers?

[Orion_]

This is what I use for sound:

Code: Select all

Init:
   if (Locksnd() != 1)
      return (false);

   SoundBuffer = Mxalloc(SOUND_BUFFER_SIZE, MX_STRAM);   // Malloc in STRam !
   if (!SoundBuffer)
   {
      Unlocksnd();
      return (false);
   }

   Settracks(0,0);
   Setmontracks(0);
   Setmode(MODE_MONO);
   Devconnect(DMAPLAY, DAC, CLK_25M, CLK_25K, NO_SHAKE);   // 24585Hz

   Setbuffer(PLAY, SoundBuffer, &SoundBuffer[SOUND_BUFFER_SIZE]);
   Buffoper(PLAY_ENABLE | PLAY_REPEAT);   // Play in Loop -> Ring Buffer

   return (true);


DeInit:
   Buffoper(0);
   Mfree(SoundBuffer);
   Unlocksnd();


[joska]

"Software" trickery for the STE DMA sound? Does it intercept reads and writes to the associated hardware registers?

If I understand this correctly there are dummy registers in the FPGA that are monitored by an interrupt driven routine. The AC97 is then set up accordingly when these registers are written to.

[simonsunnyboy]

Thanks for the explanation! So compatible HW registers are there but the actual processing is done by the modern day IC part and there is no audio generating circuit otherwise designed into the system?

@Orion_: Thanks for sharing your code, i have also taken a look at Ozk's website. It seems to me that this is the new interface to allow hardware independant audio access? So that an additional hardware driver has to provided? Some ES1371 for the Hades with PCI card and something AC97 compatible for the Firebee?

[Orion_]

I don't know about GSXB, I'm just using xbios functions, and this is working on both falcon and firebee without modification

[simonsunnyboy]

Oh really. Now you see why asking for something beyond tos.hyp as this only lists a couple of calls as being available on the Falcon. My question remains valid: is there any combined documentation available for the Falcon Sound XBIOS?

[joska]

http://dev-docs.atariforge.org/files/Falcon030_Dev_Doc_1-25-1993.pdf

[simonsunnyboy]

http://dev-docs.atariforge.org/files/Falcon030_Dev_Doc_1-25-1993.pdf

Ahh thanks, I didn't have a deep look yet but it is probably exactly what I have been missing sofar.

[nativ]

There are the XBIOS Docs relating to Milan sound somewhere... I recall downloading some thing about it all... few years back!

[joska]

Thanks for the explanation! So compatible HW registers are there but the actual processing is done by the modern day IC part and there is no audio generating circuit otherwise designed into the system?

Correct. The only thing that *generates* audio in the FPGA is the YM. DMA sound is done by the AC97 and the ColdFire DMA.