PX20		(('P' << 24) + ('X' << 16) + ('2' << 8) + '0')

/* One of these for each opened, powerpacked file, which has not yet been
** closed by the Open()'er.
*/
struct filenode
{
	struct MinNode mn;

	BPTR filehandle;
	char *new_filename, *orig_filename;
	short dirty;
};

/* One of these for each caller to NewOpen() */
struct caller
{
	struct MinNode mn;

	struct Task *tc;
};

/* For inter-process communication */
typedef struct
{
	struct Message     