0x0	4	offset/pointer to portal vertex list
0x4	1	parent room
0x5	1	child room
0x6	1	flags
	01	
	02	
0x7	1	counter
	F0	repeat counter
	0F	value
	08	set if upper nibble set

  Portals are defined by vertex tables at the given offset.  These connect the parent room with the child room and are bi-directionally visable.
  

Byte 7:
  F2= lower nibble / 2
  if upper nibble set, F2+=F2

