If you mean the DosFlatToSel and DosSelToFlat APIs, they are there because
not all pointers can be thunked by the normal means that C Set employs. 
For things like pointers to ring 0 code (I think) and others, you have to
call the APIs.  For pointers to application data, the APIs are overkill,
and, as you say, uneccesary; they're also a lot slower than the CSet
thunks!

Cheers, Graham Perks.

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