Bitfields for segment attributes:
Bit(s)	Description	)
 0	data segment rather than code segment
 1	unused???
 2	real mode
 3	iterated
 4	movable
 5	sharable
 6	preloaded rather than demand-loaded
 7	execute-only (code) or read-only (data)
 8	relocations (directly following code for this segment)
 9	debug info present
 10,11	80286 DPL bits
 12	discardable
 13-15	discard priority