Format of 386|DOS-Extender run-time parameters:
Offset	Size	Description	)
 00h  2 BYTEs	signature "DX" (44h 58h)
 02h	WORD	minimum number of real-mode params to leave free at run time
 04h	WORD	maximum number of real-mode params to leave free at run time
 06h	WORD	minimum interrupt buffer size in KB
 08h	WORD	maximum interrupt buffer size in KB
 0Ah	WORD	number of interrupt stacks
 0Ch	WORD	size in KB of each interrupt stack
 0Eh	DWORD	offset of byte past end of real-mode code and data
 12h	WORD	size in KB of call buffers
 14h	WORD	flags
		bit 0: file is virtual memory manager
		bit 1: file is a debugger
 16h	WORD	unprivileged flag (if nonzero, executes at ring 1, 2, or 3)
 18h 104 BYTEs	reserved (0)