truth5678 wrote:

Isolated the bug within the menu code itself. I believe, not positive yet, that the cycles updating in the menu bar is causing the midi bug. To test this, run Ykhwong's build of dosbox with cycles=max, test the midi, then change to cycles=25000, and then test the midi again. It seems like fixed cycles avoids the midi bug, but I believe it's actually the menu bar updating the cycles.

If not, then I will continue exploring the menu code for hints.

Yes, I can verify that cycles=max equals no MIDI. With fixed cycles MIDI works every time.

Thank you!

truth5678 wrote:

Has this clock frequency been verified by an expert like Great Hierophant?

The clock frequency hasn't been verified by Great Hierophant but Jmk (the ps1 audiocard emulator programmer) said he read the technical sheet and he found evidence that the sound chip is fed by a 4 Mhz clock instead of a ~3.5 Mhz clock.

You can find the documents here: ps1stuff.wordpress.com

Note: I tested the latest build and it seems that the pitch is now higher (correct), so probably Ykhwong already changed the code.

Myloch wrote:

@ykhwong: nice to see you back here! I saw a new version is out: did you perhaps fix the frequency of ibm ps/1 audio emulation?

I verified the source code already has the change. The source code is available at his web site so it is possible to check. 😀