The transputer instruction set consisted of 8-bit instructions assembled from opcode and operand nibbles. The binary opcodes (machine language) were identical, but preceded by a new opcode prefix. Each instruction typically consists of an "operation" or "opcode" plus zero or more "operands". A later codice 2 opcode (0x45) has no operands. Zend Opcache speeds up PHP execution by opcode caching and optimization. Additional opcode tables can exist for additional instructions created using an opcode prefix. PDP-8 instructions have a 3-bit opcode, so there are only eight instructions. Each command begins with an eight-bit opcode, followed by zero or more bytes of parameters. Note that most of the instructions used occupy a single 8-bit opcode. The opcode used indicated the history of that particular branch instruction. The opcode for this instruction is codice 2. On x86 processors, the opcode of codice 1 is codice 4. The other parts of the instruction are the opcode, and destination. The RDRAND opcode will return values from an onboard hardware random number generator. The MAC control opcode for a Priority pause frame is 0x0101.