Marmes wrote:According to datasheet you need to do a cold reboot, so crystal chip may be programmed again.
Maybe we're looking at different datasheets, or I haven't read it carefully enough yet, but I didn't find any mention of that requirement. The only exception is if the existing software disables Plug and Play isolation and/or the Crystal Key after the first initialisation. Other than that, its behaviour seems quite similar to the InterWave, in that you can repeat the isolation and configuration process without a full restart, and without re-writing the EEPROM.
As keropi said, it's not particularly relevant, but I think it's an interesting distinction nonetheless, and always like to know how different manufacturers designed their hardware. These details could be handy, however, in solving your difficulties with OPL3 versus Crystal FM. For Win 9x, if you have a DOS-level tool that disables the configuration interfaces, the Windows driver might not be able to forcibly re-enable the Crystal FM. Of course that may cause other problems, but may still be worth a try. There may be other, simpler, Windows-based work-arounds, but that may be one possibility to keep in mind.