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 Debugging real mode overlaid programs
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 Almost all CodeView compatible debuggers can be used to debug non-overlaid
 real mode programs, and many can be used to debug overlaid programs. Please
 refer to the product sections above and to the individual product
 documentation for more details for specific debuggers.

 Program problems sometimes only occur when particular pieces of code are
 overlaid or called in a certain order, so the link script command MURPHY is
 provided to attempt to force these problems to manifest themselves at
 debugging time. The MURPHY command forces the overlay manager to ensure that
 at any point in time, only one overlay is active in memory.

 This worst case scenario will force all calls to other overlays to be
 executed via the overlay manager, rather than directly transferring control
 to a nearby address in memory. This in turn should force any problems due to
 non-overlayable code or non-supported references between overlays to
 manifest themselves.

 The MURPHY command may be placed anywhere on the command line or in a link
 script file, since it is global in its effect.

 For example, to link a small test program and test the overlays in the worst
 case :

 # TEST.LNK
 BEGIN             # Start of overlays
    FILE TEST1     # The first overlaid file
    FILE TEST2     # The second overlaid file
    FILE TEST3     # The third overlaid file
 END               # End of overlays
 MURPHY            # Enable worst case overlaying
 BLI CACHE XMS 256 # Cache overlays for speed
 BLI CACHE EMS 256 # Cache overlays for speed

 The final version of the program should NOT be shipped with the MURPHY
 option enabled, since it will run slower than it should, and may fail with
 errors which would not happen under normal circumstances.