INT 10 - VIDEO - SET SINGLE PALETTE REGISTER (PCjr,Tandy,EGA,MCGA,VGA)

	AX = 1000h
	BL = palette register number (00h-0Fh)
	   = attribute register number (undocumented) (see #00017)
	BH = color or attribute register value
Return: nothing
Notes:	on MCGA, only BX = 0712h is supported
	under UltraVision, the palette locking status (see AX=CD01h)
	  determines the outcome
SeeAlso: AX=1002h,AX=1007h,AX=CD01h