Assembly Language Help (alang.hlp) (Table of Contents; Topic list)
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Processor Selection Directives
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  See also: .MODEL with .386 and .486, OPTION M510, OPTION NOKEYWORD:
 
  The processor selection directives determine which instructions may
  be assembled. You can combine processor and coprocessor selection
  directives to obtain the desired instruction set. The .8086 directive
  is in effect by default. Select a processor selection directive for more
  information.
 
            8086 80186 80286 80386 80486  8087 80287 80387 Privileged
          ┌─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬──────────┐
  .8086   │  +  │  -  │  -  │  -  │  -  │  +  │  -  │  -  │    -     │
          ├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼──────────┤
  .186    │  +  │  +  │  -  │  -  │  -  │  +  │  -  │  -  │    -     │
          ├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼──────────┤
  .286    │  +  │  +  │  +  │  -  │  -  │  +  │  +  │  -  │    -     │
          ├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼──────────┤
  .286P   │  +  │  +  │  +  │  -  │  -  │  +  │  +  │  -  │    +     │
          ├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼──────────┤
  .386    │  +  │  +  │  +  │  +  │  -  │  +  │  +  │  +  │    -     │
          ├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼──────────┤
  .386P   │  +  │  +  │  +  │  +  │  -  │  +  │  +  │  +  │    +     │
          ├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼──────────┤
  .486    │  +  │  +  │  +  │  +  │  +  │  +  │  +  │  +  │    -     │
          ├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼──────────┤
  .486P   │  +  │  +  │  +  │  +  │  +  │  +  │  +  │  +  │    +     │
          ├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼──────────┤
  .8087   │     │     │     │     │     │  +  │  -  │  -  │          │
          ├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼──────────┤
  .287    │     │     │     │     │     │  +  │  +  │  -  │          │
          ├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼──────────┤
  .387    │     │     │     │     │     │  +  │  +  │  +  │          │
          ├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼──────────┤
  .NO87   │     │     │     │     │     │  -  │  -  │  -  │          │
          └─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴──────────┘
 
  The directives that enable privileged instructions do not cause the
  processor to enter protected or privileged mode. You must write code
  to perform this transition.
 
  The .286C and .386C directives are equivalent to the .286 and .386
  directives respectively. They are provided for compatibility with
  previous versions of the assembler.
                                    -♦-