* Mouse does not move properly. 

  Under MSDOS, the mouse moved according to the acceleration settings
  in the mouse driver.  Under SDL, the mouse is measured more directly,
  and acceleration effects are not included.  As a result, the mouse
  moves slower under chocolate doom (it may be harder to quickly "whip"
  the player round for example). This needs some investigation to see
  how mouse acceleration was typically performed under DOS.

* Sound may not set volumes correctly.

  It is possible that volume of sound effects does not scale properly 
  with distance from the sound source.  This needs further investigation.

* Music plays back differently.

  The DOS music code was not in the Doom source release as Doom used
  a proprietary sound library.  The mus <-> mid conversion mostly 
  works well but some patches are different.  By closer examination 
  of which MIDI instruments are used by doom.exe, it may be possible
  to get a closer conversion.