LGDT - Load Global Descriptor Table (286+ privileged)

	Usage:	LGDT	src
	Modifies flags: None
	Loads a value from an operand into the Global Descriptor Table
	(GDT) register.
				 Clocks			Size
	Operands	 808x  286   386   486		Bytes
	mem64		  -	11    11    11		  5
	- see Instruction Timing