Daniel, the routine you posted is exactly the code in the link that Rob posted. There, it is described as a pseudo random number generator which will produce a number between 1...255. But looking at it I must agree that it looks a bit suspect... Gimme a sec while I run this through the sim, and I'll get back to you later in this thread...

If you use a free running timer, it will only give you random numbers if you read it at random times. The randomness has to come from somewhere! I would advise you to concentrate on trying to get the code you posted to work instead of going looking for an alternative.