13 Swapping

 Both FM and FD requires over 220 KB of RAM. If you shell to DOS, or
 load another program from FD, this memory is not freed. FrontDoor
 allows you to swap out the memory used by FD and FM, either to
 XMS/EMS memory or to a disk file. If you have specified that you want
 the programs to use XMS/EMS memory for swapping but there is not
 sufficient XMS/EMS memory available, the swap image is written to
 disk. The swap file is placed in the SYSTEM directory and removed
 when you return to the program.

 If you enable swapping for FD, it will be swapped out when you invoke
 a DOS shell and when you invoke other programs. The FD swap setting
 also affects the Terminal. The Terminal will not flush its
 scroll-back buffer to disk if any type of swapping is enabled for FD.

 Once the swap image has been created and written to XMS/EMS memory or
 a disk file, all used (by FD/FM) memory is freed except between three
 and five KB which will always remain in memory.

     13.1 Complete path specifications

     To avoid problems when you enable swapping to XMS/EMS memory or
     to a disk file, it is recommended that all the filename and
     directory specifications under Global > Filenames in FDSETUP
     contain complete path specifications, including a driver
     specifier.

     If you choose to swap to a disk file, it is further recommended
     that you specify a complete path to where you want the swap files
     to be placed (Global > FileNames > Swapping).


     13.2 Loading programs in a DOS shell

     Make sure that you do not load any TSR (Terminate and Stay
     Resident) programs, such as DOS' PRINT and SideKick, when you are
     in a DOS shell. Failure to follow this advice may lead to system
     lockups when you attempt to return to FD or FM.