Minecraft wiki entry for Clock, associated text: In electronics this device is commonly known as a "Linear Feedback Shift Register" (LFSR), players can make them count up, count down, create psudo-random binary sequences for testing logic circuits. In TCP/IP a 32-bit 'Linear Feedback Shift Register' is used to perform data integrity checks ie CRC-32. LFSR's also create the codes for CDMA phones and GPS (Global Positioning System).