This is an amazing WORKING 4x4 screen!
You can program it to show what you want!!
There is 11 programmable slides!!!
Because some pushed out pistons is broken when you paste a schematic, you will have to check if the piston isn't broken. (The piston is located at the back of the schematic, it is pushing a redstone block, just replace it with a normal piston, if it is broken.)
Each redstonelamp is wired to a set of pistons that pushes glass/stone:
--Stone = ON
--Glass = OFF
The screen's redstonelamps are numbered like this:
Each set of pistons has a color code. (Use it to determine the redstonelamp it is connected to) (It is the wool block):
It is for Minecraft 1.6.2