Re: [hatari-devel] STe DMA sound

[ Thread Index | Date Index | More Archives ]

On 14/04/2018 at 18:23, Vincent Rivière wrote:
With current HG sources, I have also commented out DmaSnd_GenerateSamples() as a test.
Result: Good YM music, no DMA digidrums, and no 7 KHz issue
It seems to indicate that the 7 KHz artifact comes from the DMA, unless I'm mistaken...

Other test:
dmaSnd.c, line 553:
			switch (microwire.mixing) {
				case 1:
					/* DMA and YM2149 mixing */
MixBuffer[nBufIdx][0] = MixBuffer[nBufIdx][0] /*+ dma.FrameLeft * -((256*3/4)/4)/4*/;

Note that I have commented out the DMA part (I could have simply commented out the whole line).

Result in Lethal Xcess main menu:
YM music, no digidrums... but annoying 7 KHz artifact present!
So it seems to indicate that the noise comes from YM.

Opposite conclusion of my previous test...
I need to have a rest.

NB: The only sane possibility would be that DmaSnd_GenerateSamples() trashes the YM sound by some side effect.

Vincent Rivière

Mail converted by MHonArc 2.6.19+