SPC700 help

mic_ · Post by **mic_** » Wed Apr 18, 2012 9:49 am

I'd suggest disabling echo, clearing the ADSR registers, setup the gain registers / master volume for a constant volume, setting up the sample source dir, the pitch register, clear KOF, set KON.

wiiqwertyuiop · Post by **wiiqwertyuiop** » Wed Apr 18, 2012 10:47 am

ok i think im getting closer the only problem i have now is that sound effects constantly play,is there some way to make them stop after a bit (I guess using a timer?).

mic_ · Post by **mic_** » Wed Apr 18, 2012 11:42 am

Either use a timer to key the channel off, or mark the BRR sample as non-looped if it's a one-shot sound (e.g. an explotion/scream/etc).

Bregalad · Post by **Bregalad** » Wed Apr 18, 2012 11:51 am

Have you even read my long post ?
I explained how you need to have a routine that is called regularly, and one of the first things you should do is to deal with key on, key off and pitches.

wiiqwertyuiop · Post by **wiiqwertyuiop** » Wed Apr 18, 2012 12:24 pm

Yes I read it now and it helped me very much, thank you.

Ok I got the sound effect to stop after a certain amount of frames and everything seems to work fine.... but now the sound effect plays too quietly and im not sure why. I have the master volume (left and right) set to #$7f and the volume for the voice at #$7f as well yet I can barely hear it. Here is my current code.

Bregalad · Post by **Bregalad** » Wed Apr 18, 2012 12:46 pm

I think it's a problem with the enveloppe. It looks like you write 0, 0, 0 to enveloppe regs which should normally not work (in fact its weird if you hear sound with this settings, this should result in silence !)

You should write 0xFF to ADSR1 and 0xE0 to ADSR2 to have no enveloppe (sustain at max value forever). In this setting the value in GAIN have no effect.

Alternatifely you could write 0x00 to ADSR1, and 0x7F to GAIN, to directly force the enveloppe to 0x7F. Both should be completely equivalent.

wiiqwertyuiop · Post by **wiiqwertyuiop** » Thu Apr 19, 2012 6:54 am

Er.. sorry for all the questions... but now channel 3 seems to cut in and out when I activate it for some reason. None of the other channels seem to do this and I have all the channels set the same way. Here is my current code. Thanks!

mic_ · Post by **mic_** » Thu Apr 19, 2012 7:27 am

I don't see anything in your SPC code that prevents processing the same command over and over. Does your code on the 65816 side write zero to the communication port a while after sending a "START CHANNEL X" command?

wiiqwertyuiop · Post by **wiiqwertyuiop** » Thu Apr 19, 2012 5:22 pm

mic_ wrote:I don't see anything in your SPC code that prevents processing the same command over and over. Does your code on the 65816 side write zero to the communication port a while after sending a "START CHANNEL X" command?

Yes, all im doing is making the channel stay active for as long as im holding a button, but for some reason when I hold up (which activates channel 3) it cuts in and out while the other ones don't.

KungFuFurby · Post by **KungFuFurby** » Fri Apr 20, 2012 8:26 am

Try using a different button to activate channel 3... sometimes it ends up being on the SNES end that causes a hiccup (or it could be your keyboard). Either that, or make sure your auto-fire is completely off (you may have accidentally activated it for the up key).

wiiqwertyuiop · Post by **wiiqwertyuiop** » Mon Jul 30, 2012 2:43 pm

Um... sorry if this is considered a bad bump...

After taking a break from this for a while and working on some other things I decided to try to make a functional sound engine, I first wanted to start off with just playing sound effects so I wrote this:

http://www.pastebay.net/1069545

and when i try to play it in snes9x it makes some short sounds but never plays the whole things, and i get nothing in bsnes! Getting rid of the second:

Code: Select all

mov $f2, #$4c   ;\
mov $f3, #$00   ; | Turn off all voices
mov $f2, #$5c   ; |
mov $f3, #$FF ;/

plays the whole thing but only once and still nothing in bsnes! So yeah any help would be great!

Jsolo · Post by **Jsolo** » Mon Jul 30, 2012 4:54 pm

A channel that has KOFF=1 (and does not play any sound yet) is effectively muted and will be put into release state immediately after it has been turned on; try clearing the KOFF bit for channel 0 before toggling KON.
Furthermore, you don't need to write 1 to KOFF at all; writing $FF to KOFF once at startup puts all channels into release state.

wiiqwertyuiop · Post by **wiiqwertyuiop** » Tue Jul 31, 2012 8:55 am

Ok thanks, i think im getting closer now. The sounds play correctly in snes9x, but in bsnes I get this loud beeping sound and I don't know why. Here is the code im using:

http://www.pastebay.net/1069601

wiiqwertyuiop · Post by **wiiqwertyuiop** » Fri Aug 03, 2012 5:51 pm

Does anyone have any ideas?...

If not, does anyone know of a working SPC engine I can study (Preferably one with comments

)?

Shiru · Post by **Shiru** » Fri Aug 03, 2012 5:55 pm

You can check out my engine from Christmas Craze sources (spc700.asm).

nesdev.org

SPC700 help

Re: SPC700 help

Re: SPC700 help