[W/K] :: machine code

  machine code \machine code\ n. (Computers)
     Same as machine language.
     [WordNet 1.5] machine-controlled

  machine code
       n : a set of instructions coded so that the computer can use it
           directly without further translation [syn: machine
           language]

  machine code
       
          The representation of a computer program which is actually
          read and interpreted by the computer.  A program in machine
          code consists of a sequence of machine instructions (possibly
          interspersed with data).  Instructions are binary strings
          which may be either all the same size (e.g. one 32-bit word for
          many modern RISC microprocessors) or of different sizes,
          in which case the size of the instruction is determined from
          the first word (e.g. Motorola 68000) or byte (e.g. Inmos
          transputer).  The collection of all possible instructions
          for a particular computer is known as its "{instruction set".
       
          Execution of machine code may either be hard-wired into the
          central processing unit or it may be controlled by
          microcode.  The basic execution cycle consists of fetching
          the next instruction from main memory, decoding it
          (determining which operation it specifies and the location of
          any arguments) and executing it by opening various gates
          (e.g. to allow data to flow from main memory into a CPU
          register) and enabling functional units (e.g. signalling to
          the ALU to perform an addition).
       
          Humans almost never write programs directly in machine code.
          Instead, they use a programming language which is translated
          by the computer into machine code.  The simplest kind of
          programming language is assembly language which usually has
          a one-to-one correspondence with the resulting machine code
          instructions but allows the use of mnemonics (ASCII strings)
          for the "{op codes" (the part of the instruction which
          encodes the basic type of operation to perform) and names for
          locations in the program (branch labels) and for variables and
          constants.
       
          (1995-02-15)