Technote 1070

  // Increase the space allocated for the background only application stack.
  //
  // Warning: SetApplLimit always sets the stack to at least as large as the
  //    default stack for the machine (8K on machines with original QuickDraw,
  //    24K on machines with Color QuickDraw), so the application partition
  //    must be large enough to accommodate an appropriate stack and heap.
  //    Call this only once, at the beginning of the BOA.
  //
  // Another warning:
  //    Don't bother trying to set the stack size to something lower than 24K.
  //    If SetApplLimit is called to do this, it will silently lower ApplLimit
  //    to a 24K stack. (The limit is 8K on machines without Color QuickDraw.
  //    In this sample, we don't allow an increment less than 24K.)
 
  OSErr IncreaseBOAStack (Size additionalStackSize)
  {
    OSErr retCode;
 
    // Check that we aren't running with a corrupt heap. If we are,
    // fix the problem.  This was a bug with FBA's before System 7.5.5.
    // With System Software later than 7.5.5, this "fix" is harmless.

    myZone = GetZone ();
    if (myZone->bkLim != LMGetHeapEnd ())
        LMSetHeapEnd (myZone->bkLim);
 
    // Increase the stack size by lowering the heap limit.

    SetApplLimit ((Ptr) ((unsigned long) GetApplLimit () - additionalStackSize));
    retCode = MemError ();
    if (retCode == noErr)
        MaxApplZone ();
    return retCode;
  }

pascal Boolean ShouldThisBeLaunched (void)
{
    OSErr err;
    long response;

    err = Gestalt (gestaltQuickdrawVersion, &response);
    if (err == noErr && response >= gestalt8BitQD)
        return true;
    else
        return false;
}

• Inside Macintosh: Macintosh Toolbox Essentials、Event Manager、Finder Interface
• Inside Macintosh: Interapplication Communication、Apple Event Manager
• Inside Macintosh: Processes、Process Management
• 「Be Our Guest: Background-Only Applications in System 7」develop 9（BOAについて）
• 「Technote PT 35　Stand-alone code, ad nauseam」（'INIT'について）
• 「Technote 1069　System 7.5.5」