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  Title:    Bit Tests                             Flags: O D I T S Z A P C
            80386/486 Only                               ═════════════════
                                                                         ±
  Syntax:   BT dest,src
            BTC dest,src
            BTR dest,src
            BTS dest,src
 
  See also: .386
 
  Description:
 
     Copies the value of a specified bit into the carry flag, where it
     can be tested by a JC or JNC instruction. The destination operand
     specifies the value in which the bit is located; the source
     operand specifies the bit position.
 
     BT copies the bit to the flag. BTC copies the bit and complements
     (toggles) it in the destination. BTR copies the bit and resets
     (clears) it in the destination. BTS copies the bit and sets it in
     the destination.
                                    -♦-