I recently built myself a custom CMS clone, and noticed the same problem. I also compared with the CMS emulation of PCem and with Youtube videos of real hardware, and all of them sound like my card, so DOSBox CMS emulation is definitely out of pitch.

Ah, thanks for the confirmation! I'll see if I can find where the problem lies in the DOSBox source code. It's quite annoying that my development (which I mainly do in DOSBox) sounds different than the real thing (my NuXT with SAAYM).

Make sure to check with an SVN build, because I think the issue has been resolved there: [r4010]: Patch for SAA1099/Gameblaster emulation... (commited in r4010)

Thanks, I'll check out the SVN. Funny this patch was from 2014, committed three years later, and still not in an official build 😀.

I've just tested with DOSBox r4481, DOSBox ECE r4481 and DOSBox-X 2022.09.0 and all of the presents the same incorrect behaviour. As and example, I attach a record of the Monkey Island 1 intro, taken directly from my CMS clone with two real SAA1099 chips, which sounds exactly as 86box and PCem emulation: https://www.youtube.com/watch?v=Ur-zXDIUB3U

And a recording from DOSBox, that allows to crearly apreciate the issue:

Maybe that commit didn't fixed the problem correctly, or it was reintroduced by a later regression, but there is still an issue.

EDIT: tested also with DOSBox Staging 0.80.1 and it sounds correctly. Something weird is going on.

In my tests, pitch changes occur when the saa1099 sample generation rate does not match the mixing sample rate. After the clock rate changes committed in r4010, subsequent updating to the then-latest MAME sound cores introduced a difference in rates. The attached patch (experimental for now) appears to resolve the issue in current source; however, the latest saa1099 core may (I'm not sure) have a method for changing the sample generation rate that is not solely based on the clock rate.

Edit: revised the patch with a better/safer default sample rate.

I've also tested with DOSBox Staging, and it does get the pitch correct. Hopefully the patch can make it into an "official" DOSBox release.