AMS 2.05

I have a ti-89 AMS 2.05 and I wonder why there's still a black line when I shut it off.

Also, I wanna know what is the best shell or OS whatever to put on it.

Finally, does someone know how to put custom things on my calc like sec, cosec, cotan, carsin, arccos??

thanks a lot

Ray Villo

[remember that 0,9999999999=1]