The Microsoft Windows Software Development Kit (SDK) includes a debugging version of the MMSYSTEM module to aid in debugging applications that use multimedia services. This version of MMSYSTEM.LIB displays commands sent to MCI and performs error checking unavailable in the retail version.
To control the MCI debugging output, add an MCI entry to the [mmsystem] section of SYSTEM.INI. Assign the value 1 to this entry (MCI = 1) to enable MCI debugging output. The debugging output returns to the Windows function DebugOutput a string representation of each MCI command. To disable the MCI debugging output, either remove the MCI entry from the [mmsystem] section of SYSTEM.INI or assign the value 0 to the entry.
The services in the debug MMSYSTEM module supplement other Windows debugging services and tools provided with the Windows Software Development Kit. See the Microsoft Windows Programming Tools manual provided with the SDK for information about using these debugging tools.