BUD switch

The BUD Switch was a block that was possibly planned to be added in the Redstone Update for use with redstone circuitry. BUD stands for Block Update Detector.

Configurations of such a device have existed in Minecraft due to a glitch labelled as a "feature", allowing circuits to detect block updates. This block would simplify the process into one block. Although it is possible to make a B.U.D block. All you have to do is put in a command block this command: "testfor minecraft:(name of block) block state x y z x1 y1 z1 r=(blocks)" for any block in minecraft. Italic text means that you don't have to have the radius but it is helpful for compact but not accurate redstone circuts. In this command the command block looks for a block and block state. I.E an off/on lever, tnt, closed/opened doors. This is helpful for having a map or server, as you can protect your house from being griefed. You can also have a complex security system that can teleport a player away or into lava or a monster pit even to name a few places, or even a bedrock room where they cannot escape. If the command block finds the block and the optional block state the command block will when set up to a comparator will set off a redstone signal which can activate a command or set off a self destruct switch. Which can be used in horror maps. Or if you want to go into a room and set up a mine field automatically using the /setblock commands the link goes to the commands page. Or you can even wirelessly greif a base or house or world with this as you can set a block to tnt and by it redstone block which will activate the tnt thus explosions follow.

History
Redstone-Schaltkreise/BUD Schalter BUD Switch/es BUDスイッチ BUD schakelaar Датчик обновления блока (блок) BUD开关