Int 41 Fn 0050  P - Ms Windows Debugging Kernel - "definedebugsegment"     [G]

   AX = 0050h
   BX = segment number in executable (0-based)
   CX = selector
   DX = instance handle
   SI = segment flags (0=code, 1=data)
   ES:DI -> module name of owner

Return: ???

See Also: AX=0012h,AX=004Fh