INT FF - PCIBM PC/FORTH - GRAPHICS API(Application Program[ming] Interface) The defined set of calls which a program may make to interact with or request services of the operating system or environment under which it is running.  Because the inputs and outputs of the calls are well-defined, a program using the API can continue using the identical calls even if the internal organization of the program providing the API changes. - VIDEO STATUS CHANGE
	BX = 0000h
	DS:SI -> FORTH program counter
	SS:BP -> FORTH parameter stack
	SS:SP -> FORTH return stack
	DS:DX -> FORTH video parameter area
Desc:	called to inform graphics driver of any status changes such as video
	  mode changes, character color changes, graphics XOR mode turned on
	  or off, etc.; also used as an installation check
Index:	installation check;PCIBM PC/FORTH