Format of segment descriptor table entry:
Offset	Size	Description	)
 00h	WORD	segment limit, low word
 02h  3 BYTEs	segment base address, low 24 bits
 05h	BYTE	access mode (see #00502)
 06h	BYTE	386+ extended access mode (see #00505)
 07h	BYTE	386+ segment base address, high 8 bits
SeeAlso: #00500,INT 2C/AX=0002h,INT 31/AX=0009h