Using the MIDI Mapper

MIDI files played with the Media Player (MPLAYER.EXE) application supplied with Windows 3.1 are played according to the configuration of the current MIDI setup, NOT the current value of the patch maps or key maps that appear in the Names box.


The patch maps and key maps that are used are specified within each MIDI setup. Changing the current patch map setting that is visible from the MIDI Mapper Show Patch Maps option in the Name box will not affect the patch map that is used by the Media Player unless the current MIDI setup uses that patch map. The same functionality applies to the Key Maps setting of the Show option of the MIDI Mapper.


If Media Player is not playing MIDI files correctly, the current MIDI setup may need to be changed or a custom (new) MIDI setup may need to be created for the system.


Use the information below to determine if a suitable MIDI map exists for the system, or to create a new MIDI map.

Determining the Current MIDI Setup

1. Run Control Panel.
   
2. Run the MIDI Mapper application. If the MIDI Mapper icon is not present, this indicates that no MIDI-compatible driver is installed. Before proceeding, you must correct this problem by installing a MIDI-compatible driver using the Drivers application within the Control Panel.
   
3. After the MIDI Mapper starts, change to Show Setups by pressing ALT+S. The current MIDI Mapper setup will be displayed in the Name box.
   

Components of a MIDI Map

A MIDI map is composed of four components:

1. Dest Chan (Destination Channel): The channel used by the synthesizer to play the sounds on the source channel.
   
2. Port Name: The MIDI output port that the sounds on the source channel are sent to or played on. A correct value in this box is key to producing desired results. Determining the correct port name is discussed later in this article.
   
3. Patch Map Name: The name of the patch map to be used with the source channel. Patch maps are used to define which instruments are to be used with the MIDI device. Different patch maps can be assigned for each channel through this field.
   
4. Active: Determines if MIDI information from the source channel is sent to the port.
   

Choosing Which Channels to Configure

A few general guidelines are offered below. Consult the sound card manufacturer to determine which channels the sound card supports if MIDI files do not sound correct when used according to the guidelines below.


FM Synthesizers will work best with the last four channels, 13-16. Common sound cards in this category are the Media Vision Thunder Board and the Sound Blaster I and II cards.


MIDI cards with genuine synthesizers (based on actual sampled sounds) will work best with the first ten channels, 1-10. Common sound cards in this category are the Roland LAPC-1, Roland Sound Canvas, and Turtle Beach MultiSound card.

Examining MIDI Port Settings of a MIDI Map

The proper port should be verified for each channel supported by the MIDI device. If no sounds are played from Media Player with MIDI files, check the port settings of the MIDI map very carefully. Many sound cards have multiple ports and the correct one should be chosen.


For example, the Media Vision Pro AudioSpectrum card supports two MIDI ports: one for connecting an external MIDI connector box through a 15-pin connector, the other for an internal FM synthesizer.


When editing a MIDI map, view the port settings supported by the synthesizer by highlighting the Port Name box and examining the list box (press ALT+DOWN ARROW). This reveals the port options for the Pro AudioSpectrum card:

In this case, the Pro Audio MIDI Output option is the external MIDI port, and the Media Vision FM Synth option is for the built-in MIDI synthesizer connected to the same speakers that generate output for .WAV files.


If nothing is connected to the external MIDI port, no MIDI sounds will play if this port is selected. If .WAV files can play (startup sounds, and so on), then an internal synthesizer should be able to be selected if the card supports MIDI.

Problems Playing Certain MIDI Files

Not all MIDI files are the same. Depending on how the MIDI file was authored or created, the MIDI file might contain MIDI information on channels other than those supported by the MIDI device. Usually a MIDI file will contain data on channels 1-10 or 13-16. If no output is produced, create a MIDI map that uses all channels. (The MIDI file supplied with Windows 3.1, CANYON.MID, contains MIDI information on all channels.)


For more information, see pages 185-198 in the "Microsoft Windows User's Guide" version 3.1 manual.