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3 definitions found
 for machine code
From The Collaborative International Dictionary of English v.0.48 :

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

From WordNet (r) 3.0 (2006) :

  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]

From The Free On-line Dictionary of Computing (18 March 2015) :

  machine code
  machine language
  
      The representation of a computer program that is
     read and interpreted by the computer hardware (rather than by
     some other machine code program).  A program in machine code
     consists of a sequence of "instructions" (possibly
     interspersed with data).  An instruction is a binary string,
     (often written as one or more octal, decimal or
     hexadecimal numbers).  Instructions may be 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".
  
     Each instruction typically causes the Central Processing
     Unit to perform some fairly simple operation like loading a
     value from memory into a register or adding the numbers in
     two registers.  An instruction consists of an op code and
     zero or more operands.  Different processors have different
     instruction sets - the collection of possible operations
     they can perform.
  
     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 action the operation code 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 programming languages.  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.  Other languages are either
     translated by a compiler into machine code or executed by an
     interpreter
  
     (2009-06-16)
  

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