When doing some recent audio testing, I came across some Prince of Persia MT-32 compatibility issues.

With an MT-32 with either firmware 1.04 or 1.05, Prince of Persia's MT-32 music does not play back correctly. It plays incorrect notes for a few seconds before stopping on a sustained note. I've tested this in a few setups including with an MPU-401AT, an ESS Solo-1 and a Roland RAP-10.

If I play it on an MT-32 with firmware 1.07, it plays back correctly. I've tested the latter with both an MPU-401AT and an ESS Solo-1 PCI sound card via the joystick port.

With the older firmware versions, I discovered that if I ran The Secret of Monkey Island first for a few seconds, quit, and then launched Prince of Persia, it would playback correctly. This was the case for both the 1.04 and 1.05 firmware.

I'm assuming that The Secret of Monkey Island is sending some sort of SysEx command(s) that is doing something to the MT-32 allowing Prince of Persia to work correctly. I'm also assuming that whatever changed in the 1.07 firmware maybe caused some sort of commands to initiate on power up by default?

From what I've found on the 1.07 firmware, the update includes:

• Fixes a bug related to specific values in uninitialized sram on startup causing the unit to act bizarre.

Maybe The Secret of Monkey Island is initializing something that allows it to work with Prince of Persia?

Before I dig much deeper, I'm curious if anyone else can shed any light on this. Any suggestions for SysEx commands to test out?