machine code

3 definitions found

machine code - Collaborative International Dictionary of English v.0.48 :

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

machine code - WordNet (r) 2.1 (2005) :

  machine code
      n 1: a set of instructions coded so that the computer can use it
           directly without further translation [syn: machine code,
           machine language]

machine code - Free On-line Dictionary of Computing (26 May 2007) :

  machine code
  machine language
  
     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)