Ah .. "rnd" I used that alot on my amstrad !!! In computer, there is no true random simulator ( except Win98 ;) . When you use a random algorythm, you got to tell it where to start . I remember the "randomize time" mnemonic in basic, wich used the actual time as the seed of the random algorythm . It was meant to give better hazard . I assume some procedural functions use seeds like that, and that the random algorythm is included in the shader function . When "shuffle" must be something like "randomize time", the seed allow the user to use the same random routine several times in different channels . Just a guess, any programmers around ? litst