NEG - Two's Complement Negation

	Usage:	NEG	dest
	Modifies flags: AF CF OF PF SF ZF


	Subtracts the destination from 0 and saves the 2s complement of
	"dest" back into "dest".


				 Clocks			Size
	Operands	 808x  286   386   486		Bytes

	reg		  3	2     2	    1		  2
	mem		16+EA	7     6	    3		 2-4  (W88=24+EA)


	- see Instruction Timing