BLINKER EXECUTABLE DUAL       Specify creation of dual mode executable.
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 Purpose  : Specify the creation of a dual mode executable.

 Syntax   : BLINKER EXECUTABLE DUAL [<minimum extended
            memory>]

 Default  : <minimum extended memory> is 512KB

 Example  : # Run in protected mode if at least 2MB available
            BLINKER EXECUTABLE DUAL 2048

 This command specifies that Blinker should produce a dual mode executable
 that can be run in either real or protected mode. The optional parameter to
 this command is the minimum amount of available extended memory required to
 execute in protected mode.

 At runtime, the program will be executed in REAL mode if any of the
 following are true:

    .  The CPU is less than an 80286
    .  The CPU is an 80286 or better, but there is no DPMI, VCPI or XMS host.
    .  The CPU is an 80286 or better, but the amount of available extended
       memory is less than the specified minimum amount.

 Otherwise the program will be executed in protected mode.

 If no BEGINAREA and ENDAREA commands are used with BLINKER EXECUTABLE DUAL
 then ALL overlaying will be disabled, which will create a non-overlaid
 program which will run in both real or protected mode.

 Note: Dual mode programs must be specifically written to work in both real
 and protected mode. Use of this command does not imply that the program will
 run successfully as a dual mode program, it simply sets the format of the
 .EXE accordingly.

 For a detailed description of the requirements of a dual mode program, see
 Chapter 5 'Coding for Dual mode'.