🚀 go-pugleaf

In article <724051521.AA09634@csource.oz.au> John.Gibney@f386.n632.z3.fidonet.org (John Gibney) writes:
/In VAX/VMS, symbol libraries are used to return status
/values, etc. for the results of calls to system services.
/This allows programs to test against, for example,
/SS$_NORMAL, for a success status.
/One of the main advantags of this is to aid program
/maintenance - if the developers of the O/S decide to change
/a status value, existing programs won't break - they will
/(probably) only need to be relinked.
/I would like to know if anyone has any ideas on how a
/similar scheme may be implemented in DOS.  I have 1 idea of
/using #include files, but I think that's a bit gauche,
/sometimes...  Any other clues?

Handling of huge pointers is done just this way. Externals __AHINC
and __AHSHIFT are referenced which provide the information at runtime
as to the gaps between selector values. This enables the same program
to run in real mode and various protected modes (as in Windows PM,
DOS extender PM, and 16 bit OS/2). The values of __AHINC/SHIFT are
provided either by the runtime library or are exported by the operating
system DLL.