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Example SGDK project for MDSDRV

This project contains the MDSDRV C language wrapper and an example of how to use MDSDRV in a C program using the Sega Genesis Development Kit (SGDK).

How to use MDSDRV in your own SGDK programs

  1. Copy inc/mdsdrv.h, src/mdsdrv.c, and res/mdsdat.res into your project.
  2. Copy mdsdrv.bin, mdspcm.bin, mdsseq.bin from the MDSDRV out directory.

Using outside SGDK

It is possible to use this code outside SGDK, however the following apply:

  1. The mddseq data must be aligned to start at an even offset. (This should normally be done automatically by the compiler)
  2. The PCM data must be aligned to start at a 32kb bank boundary. To do so, prepend __attribute__((__aligned__(32768))) to the array definition.
  3. When building mdsdrv.c, make sure to build with std=gnu11 (or higher).

Important notes

To initialize MDSDRV, call MDS_init().

The sound driver runs on the 68000 and thus it needs to be updated from user code every frame. To do this, call MDS_update(). Make sure that the sound driver has been initialized (using MDS_init()) before calling the update function.

To play a song, use MDS_request(). This function takes two parameters, the first defines the request slot. The second parameter is the sound knumber.

There are 4 request slots available, the lowest priority one (3) is intended for use with background music (BGM). As such it has the alias MDS_BGM. The other slots are called MDS_SE1, MDS_SE2 and MDS_SE3. Only the BGM track can be faded out using the MDS_fade() function.

This should be a given, but you cannot have SGDK's included Z80 sound drivers running running at the same time as MDSDRV. So, if you have already initialized a Z80 driver in SGDK, call Z80_unloadDriver() before MDS_init(). And when you want to use the SGDK drivers again, make sure you stop calling MDS_update() first.

Most of the API functions are defined in mdsdrv.c and used in main.c, so please look in those files for more information.