Moves all sprites and viewports on a channel by a relative offset of xdist,ydist at a speed of speed pixels per frame. If speed is negative, it is seen as the number of steps to complete the movement in.
For example:
"M 10,10,-10"
Means move 10 pixels right and 10 pixels down in 10 steps.
"M -10,-10,1"
Means move 10 pixels up and 10 pixels left at a speed of 1 pixel per frame.
See also the Move Sprite and Move Viewport commands.