Int 15 Fn BF02  - Rational Systems DOS/16m - Installation Check            [E]

   AX = BF02h
   DX = 0000h

Return: DX = nonzero if installed
       DX:SI -> XBRK structure (see below)

Note:  this function is also supported by DOS/4G

See Also: AX=BF01h,AX=BFDCh,AX=BFDEh/BX=0000h

See Also: INT 21/AH=FFh/DH=0Eh,INT 2F/AH=A1h,INT 2F/AX=F100h,INT 2F/AX=FBA1h

Format of XBRK structure:
Offset Size    Description
 00h   DWORD   linear address of first available byte
 04h   DWORD   linear address of last available byte + 1 ???
 08h   DWORD   real-mode address of XBRK structure???
 0Ch   DWORD   ???
 10h  2 BYTEs  ???
 12h   WORD    segment of ???
 14h  8 BYTEs  ???
 1Ch 512 BYTEs protected-mode IDT
21Ch  N BYTEs  protected-mode GDT