Audio Sync Option

gaijinx1 · Post by **gaijinx1** » Tue Sep 28, 2004 2:06 am

I noticed that most emulators have the option to sync the sound which makes the music and sound effects much better. Why doesn't Zsnes come with that option!?!? If it did, that would make Zsnes that much more
accurate.

Post by **Nach** » Tue Sep 28, 2004 2:39 am

So you're saying you want an option to disable ZSNES' sound sync?

snkcube · Post by **snkcube** » Tue Sep 28, 2004 7:15 am

What a strange request.

Noxious Ninja · Post by **Noxious Ninja** » Tue Sep 28, 2004 3:48 pm

Depends. Timing isn't perfect yet, so you could say the SPC700 and main CPU aren't "synced". Although, for most games, this is irrelevant, as it works just fine.

JFD62780 · Post by **JFD62780** » Wed Sep 29, 2004 6:31 am

I think he means he wants SNEeSe-style smooth sound effects. Hell, so do I, but I'm patient at the very least!

Nightcrawler · Post by **Nightcrawler** » Wed Sep 29, 2004 2:10 pm

What technical reasons are there as to why it's difficult to sync the main CPU and sound CPU in the emulator?

If memory serves me, there was a problem getting a 100% accurate clock speed from both chips.

Post by **Nach** » Wed Sep 29, 2004 3:38 pm

Can you say with any certainty how fast either chip runs? Exact number we're talking here.

Post by **grinvader** » Wed Sep 29, 2004 4:09 pm

Nach wrote:Can you say with any certainty how fast either chip runs? Exact number we're talking here.

Google gave me this:

Code: Select all

    * CPU: 16-bit Custom 65C816 running at 1.79, 2.68 or 3.58 MHz (changeable)
    * RAM: 1 Mbit (128 Kbyte)
->  * Memory Cycle Time: 279 ms
    * Picture Proccessor Unit: 16-bit
    * Video RAM: 0.5 Mbit (64 Kbyte)
    * Resolution: 256x224, 512 x 448 pixels max hi res and interlaced modes
    * Colours Available: 32,768 colours
    * Max colours on screen: 256 colours
    * Max sprite size: 64 x 64 pixels
    * Max sprites: 128 (32 per line)
    * Min/Max Cart Size: 2 Mbit - 48 Mbit
    * Audio RAM: 512 Kbit
    * Sound chip: 8-bit Sony SPC700
    * Sound channels: 8, uses compressed wave samples
->  * Controller Response: 16 ms
    * Pulse Code Modulator: 16-bit
    * Power Input: 120V AC, 60Hz, 17 Watts
    * Power Output: 10V DC, 850 mA (NTSC), 9V AC (PAL)

Does this help ?

Nightcrawler · Post by **Nightcrawler** » Wed Sep 29, 2004 6:43 pm

Nach wrote:Can you say with any certainty how fast either chip runs? Exact number we're talking here.

I can say the speed no more accurate than the 3.58Mhz etc.. for CPU and 2.048Mhz for SPC700.

I assume the problem then is because that is not accurate enough to timing sensetive operations.

Based on the numbers given, you can calculate your cycle time for both chips. Ok, your cycle time will be slightly innaccurate compared to the real hardware, but why does that matter? The ratio between the two chips will be in sync.

I guess I do not understand the relationship between the two chips enough detail. You should be in sync none the less.

Zuzma · Post by **Zuzma** » Thu Sep 30, 2004 1:22 pm

I'm probably wrong on this since I don't know much about this stuff but there's more to the timing then the speed of the processors. Bus timing, DMA, HDMA, IRQs etc.

Nightcrawler · Post by **Nightcrawler** » Thu Sep 30, 2004 1:45 pm

zuzma wrote:I'm probably wrong on this since I don't know much about this stuff but there's more to the timing then the speed of the processors. Bus timing, DMA, HDMA, IRQs etc.

Right.. but the problem is the sound syncing with video. Offhand I don't think you can DMA data to the APU. It has it's own I/O ports for that. Same goes for HDMA. IRQ's should also be independent of the APU.

I understand your point though. There is definitely more to timing than just the clock speeds. I'm just trying to get someone to tell me exactly why it's a problem.

I'm not claiming I can do a better job or even as good of a job. I just would like to know for my own knowledge.

Maybe if Pagefault is feeling less grumpy and perusing the board, maybe he can shed some light on the subject. Maybe he needs to get back on that bong of his!

Zuzma · Post by **Zuzma** » Thu Sep 30, 2004 2:49 pm

I wasn't exactly trying to help the orignal poster but you did get my point. Err and I really know nothing compared to you guys.

kode54 · Post by **kode54** » Thu Sep 30, 2004 5:18 pm

It is possible to H-DMA to the APU, the exact clock rates are known, and most emulator implementations use some assembly code that sync on a ratio of the 5A22 master clock, or even a ratio of 5A22 to SPC instructions, regardless of how many cycles they require to execute, as it the case with ZSNES. *Whew*

Nightcrawler · Post by **Nightcrawler** » Thu Sep 30, 2004 5:33 pm

Ok.. thanks for the info. That confirms though that H-DMA can be ruled out as a sync problem.

kode54 · Post by **kode54** » Thu Sep 30, 2004 5:49 pm

How is H-DMA not a sync problem? Since the 5A22 is stopped for H-DMA operation, since H-DMA setup consumes additional cycles and such, the effective 5A22 clock rate changes. Since communication depends on both clocks, that which affects one clock (DMA, H-DMA, $4000-$41FF accesses, fast/slow memory access, etc.) affects sync.

Step back for a moment to gaze upon the big picture.

Nightcrawler · Post by **Nightcrawler** » Thu Sep 30, 2004 10:34 pm

Why is the 5A22 being stopped and the others are not? That doesn't happen on the real hardware. No clocks are stopped correct?

Your effective clock rates should not change. Everything is virtual. Your clocks should always be constant. You don't increment a master cycle counter until you've done everything that is supposed to be done for that cycle. Everything else should be tied into the master counter and not be advancing either.

kode54 · Post by **kode54** » Fri Oct 01, 2004 11:52 pm

DMA operations use both buses. Regardless of where it's executing from, the CPU must wait until at least one of the buses is free.

Nightcrawler · Post by **Nightcrawler** » Sun Oct 03, 2004 5:04 pm

I don't think we're quite on the same page. I'm missing something. Got any links to some good docs on the subject? Most ones I've looked through don't go into much detail on the subject matter we're talking about.

kode54 · Post by **kode54** » Sun Nov 21, 2004 12:48 am

I am on the "MKendora pointed this topic out on IRC, but doesn't want to get any more involved than suggesting that somebody else post known information" page.

flinx · Post by **flinx** » Fri Dec 03, 2004 6:10 am

Then games with slowdown wouldn't have it anymore but the sound effects and music will stay the proper pitch and tempo. Personally I'd like to use it in Jurassic Park. Inside buildings there is seems to be a true 3D engine rendering walls and the occasional countertop. However the framerate in the real SNES and ZSNES seems like about 6 per second. If I could double that while not speeding up the sound, that would kick ass. When I disable Auto Framerate it speeds up nicely but the sound suffers.

BTW, last night I found the hex address and value for infinite health for "Jurassic Park (U) (V1.1)", it's 7E02EB00 That was after trying the codes on websites. Then I googled for that exact address and it returns a single page: http://www.gscentral.com/codes.pl?dev=p ... es&game=jp
I believe only the first thee codes work for (V1.1), the others are the same as found on other sites.

Dmog · Post by **Dmog** » Fri Dec 03, 2004 8:26 am

flinx wrote:Then games with slowdown wouldn't have it anymore but the sound effects and music will stay the proper pitch and tempo. Personally I'd like to use it in Jurassic Park. Inside buildings there is seems to be a true 3D engine rendering walls and the occasional countertop. However the framerate in the real SNES and ZSNES seems like about 6 per second. If I could double that while not speeding up the sound, that would kick ass. When I disable Auto Framerate it speeds up nicely but the sound suffers.

Bwahaha haha!! Awww... (wipe tear) Promote that guy!
That guy...has a vision... The emulation scene could use people like you son.

Reznor007 · Post by **Reznor007** » Sat Dec 04, 2004 12:27 am

Dmog wrote:
flinx wrote:Then games with slowdown wouldn't have it anymore but the sound effects and music will stay the proper pitch and tempo. Personally I'd like to use it in Jurassic Park. Inside buildings there is seems to be a true 3D engine rendering walls and the occasional countertop. However the framerate in the real SNES and ZSNES seems like about 6 per second. If I could double that while not speeding up the sound, that would kick ass. When I disable Auto Framerate it speeds up nicely but the sound suffers.
Bwahaha haha!! Awww... (wipe tear) Promote that guy!
That guy...has a vision... The emulation scene could use people like you son.

As funny as that may sound, it does work in some games. In MAME you can run NeoGeo games(Metal Slug 2 for example) and overclock the main CPU to 2x speed. This removes the slowdowns that happen, and the audio stays at the right speed. You can only overclock stuff with cheats enabled, but it does work.

Dmog · Post by **Dmog** » Sat Dec 04, 2004 10:04 am

Reznor007 wrote:
Dmog wrote:
flinx wrote:Then games with slowdown wouldn't have it anymore but the sound effects and music will stay the proper pitch and tempo. Personally I'd like to use it in Jurassic Park. Inside buildings there is seems to be a true 3D engine rendering walls and the occasional countertop. However the framerate in the real SNES and ZSNES seems like about 6 per second. If I could double that while not speeding up the sound, that would kick ass. When I disable Auto Framerate it speeds up nicely but the sound suffers.
Bwahaha haha!! Awww... (wipe tear) Promote that guy!
That guy...has a vision... The emulation scene could use people like you son.
As funny as that may sound, it does work in some games. In MAME you can run NeoGeo games(Metal Slug 2 for example) and overclock the main CPU to 2x speed. This removes the slowdowns that happen, and the audio stays at the right speed. You can only overclock stuff with cheats enabled, but it does work.

Yeah I know, heck, you can even do that in Z to some extend. Raise the % of execution to 150% and you'll experience less slowdowns (slowdowns that would actually occur on the Snes) Fwiu, this is supposed to be a quick way to "fix" some games that normally don't work because of the timing problems.

While we're on the subject of basterdized emulation: Why not emulate the Snes CPU at something like 3x the normal speed...and then implement hacks for every game that got broken as a result? So that no slowdowns will ever occur and all the kiddies will be happy.

gaijinx1 · Post by **gaijinx1** » Sat Dec 04, 2004 3:32 pm

What I meant to say is, is there any way to improve the timing on the SPC700 and the Snes CPU. I'm asking this because games like Earthbound suffer in sound, try out the moves Teleport A and Teleport B,
you'll see what I'm talking about. Repeated sound effects suffer, why?

Noxious Ninja · Post by **Noxious Ninja** » Sat Dec 04, 2004 10:33 pm

gaijinx1 wrote:What I meant to say is, is there any way to improve the timing on the SPC700 and the Snes CPU. I'm asking this because games like Earthbound suffer in sound, try out the moves Teleport A and Teleport B,
you'll see what I'm talking about. Repeated sound effects suffer, why?

You can try SNEeSe. It's supposed to have better timing.

ZSNES board

Audio Sync Option

Audio Sync Option

Re: Audio Sync Option

Run the 65C816 faster but not the SPC700 because

Re: Run the 65C816 faster but not the SPC700 because

Re: Run the 65C816 faster but not the SPC700 because

Re: Run the 65C816 faster but not the SPC700 because