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FRE returns several types of information about available memory. See "Usage
Notes" for complete details.
 
FRE(stringexpression$)
FRE(numeric-expression%)
    ■ The argument stringexpression$ can be a string literal or a string
      variable.
 
Usage Notes
    ■ The values returned for different types of arguments depend on whether
      you are using near strings or far strings:
 
      Function               Near strings            Far strings
      ═════════════════════  ═════════════════════   ═══════════════════════
      FRE(a$)                Remaining space in      Remaining space in
                             DGROUP (in bytes)       a$'s segment (in bytes)
      FRE("string literal")  Remaining space in      Remaining space for
                             DGROUP (in bytes)       temporary strings (in
                                                     bytes)
      FRE(0)                 Remaining space in      Error message: "Illegal
                             DGROUP (in bytes)       function call"
      FRE(-1)                Remaining space in      Remaining space in
                             far memory for DOS      far memory for DOS
                             (in bytes);             (in bytes);
                             long integer            long integer
                             2147483647 (for OS/2)   2147483647 (for OS/2)
      FRE(-2)                Remaining stack space   Remaining stack space
                             (in bytes)              (in bytes)
      FRE(-3)                Remaining space in      Remaining space in
                             expanded memory         expanded memory
                             (in kilobytes)          (in kilobytes).
      FRE(any other number)  Error message:          Error message:
                             "Illegal function       "Illegal function
                             call"                   call"
 
Using FRE(-3) and Expanded Memory
    ■ If expanded memory is not available, FRE(-3) returns the message
      "Feature unavailable."
    ■ If you start QBX without the /E:n switch, you will be using all
      expanded memory available on your computer.
    ■ If you start QBX with the /E:n switch, you can limit the amount of
      expanded memory available to your program. For example, if your
      computer has 5 megabytes of expanded memory but you want to use
      only 4 megabytes of expanded memory, you would start QBX with this:
 
        QBX /E:4096
 
      If you have specified 4 megabytes of expanded memory as shown above,
      and then you use 2 megabytes of expanded memory in your program,
      FRE(-3) will return 2048.
    ■ If you are using BC to run a program with expanded-memory overlays,
      the value returned by FRE(-3) is based on the total amount of
      expanded memory available. (When using overlays, you cannot limit
      the amount of expanded memory used by your program.)
    ■ For more information on using expanded memory, see
      ◄Using Expanded Memory►.
    ■ For more information on memory allocation, see Chapter 15,
      "Optimizing Program Size and Speed" in the Programmer's Guide.
 
Important
    ■ FRE(-2) returns meaningful values only when a program is
      executing. Values returned by FRE(-2) are not accurate when the
      function is called from the Immediate window, during program
      tracing, or when watching a variable. The unused stack space
      indicates how much stack is needed so that DGROUP can be reclaimed.