sys/i386/isa/sound/HOWTO_MIDI

The following file describes the procedure for adding modules to MIDI
Please READ the main documentation files for the driver first!!!


 Example: We have a sound card with a MIDI chip & port on it
          and, we call it  the 'MYBLASTER' card:

 **************************************************************************

  0: Run 'configure'. Select the MIDI on CHIP support option.

  1: Write a midi driver module; 'blast_midi.c'
        (with functions for open,close,read,write,attach.)

  1a: Write all functions except the 'attach' the way you want.

      For the 'attach' function, look at a model in the 'pro_midi.c'
      file. Just dup it in the same fashion. For the 'generic_midi_operations'
      structure which is required, see file 'dev_table.h'.

  2:  We called the 'attach' function: 'blast_attach'.

      Go to the file 'dev_table.h' and add your driver name and the function
      pointer ( which is 'blast_attach' ) to the 'midi_supported' table.

  3:  You are almost set.  Go and make a reference
      to an 'exclude constant'; say EXLCUDE_BLAST_MIDI in your module
      (refer to the 'pro_midi.c' file for model). Also make sure to
      add the constant to the file 'sound_config.h' (for example, look
      where the constant EXCLUDE_PRO_MIDI is in the file.)

  4:  Add the line

        #define ALL_EXTERNAL_TO_ME

      as the 1st line of your  'blast_midi.c' file. This happily, makes
      you ignorant of everything else specific to the driver! :).

  4a: And of course, don't forget to make a device :). Note that your
      minor number should be = ( 15 + position of your driver in the
      'midi_supported' table in the 'dev_table.h' file ).

      Eg: Your driver is the second one in the table. viz midi_supported[1].
      Your device minor number should be ( 15 + 1 = 16 ). Then, make the
      reference to your device as, say CMIDI_DEV_BLAST in the file
      'sound_config.h'. Also add this in 'soundcard.c' for the open, read,
      write and close routines. See files for example using CMIDI_DEV_PRO
      (which is the ProAudioSpectrum on chip MIDI).

  5:  You are all set. If ever you have problems, follow the same model
      as the file 'pro_midi.c', except for substituting your own functions!