sound fx problem [APU related]

Zepper · Post by **Zepper** » Mon Jul 13, 2009 10:56 am

- In this topic, the explode.nsf fails in my emu. Could someone help me? From my first testing, it's not related with sweep or envelope...

- Here's a WAV record package (20kb) for you to listen. There are 2 files: explosion.wav is my emu output, megaman3.wav is how it should be played.

jsr · Post by **jsr** » Mon Jul 13, 2009 3:39 pm

This reminded me of a similar problem I had when I worked on my NSF player years ago, but that time it was noticeable in the song Daisuke by Wiz (you can find it on 2a03.org). Try playing that file in your emu and compare it to other players, if it starts to sound different 12 seconds into the song then it's probably the same problem. It was a long time ago, but I think it was caused by the sound player trying to read from the APU registers, and returning $40 to simulate an open bus solved the problem (if I remember correctly).

Hope this helps.

Zepper · Post by **Zepper** » Mon Jul 13, 2009 4:47 pm

Nope.

This song uses FDS audio and my emu doesn't support it.

jsr · Post by **jsr** » Tue Jul 14, 2009 3:35 am

Ok, but I still think it's the same problem since it was related to songs created with a certain version of MCK. Did you try to return $40 on APU register reads?

Zepper · Post by **Zepper** » Tue Jul 14, 2009 5:53 am

- What register? An invalid one? Usually, it returns address >> 8, or 40h.

jsr · Post by **jsr** » Tue Jul 14, 2009 9:08 am

I checked explode.nsf in my player, and indeed the file tries to read from $4003 and $4007. Changing the return value of these reads from $40 to $00 gives the same effect as the file you recorded.

If you do return correct values then I'm not sure what's wrong. I'd verify the return values.

Zepper · Post by **Zepper** » Tue Jul 14, 2009 11:22 am

- Fixed. Thank you so much. ^_^;;