INT 15 - Tandon memory mapper - Tandon MAPPER HARDWARE INITIALIZATION CHECK ??? 
	AX = F200h
	CX = 454Dh
Return: CF clear if hardware already initialised
	    BX = upper RAM(Random Access Memory)	See also DRAM, SRAM. areas in use
		bit 0: C000-C3FF
		bit 1: C400-C7FF
		...
		bit 11: EC00-EFFF
	CF set if hardware not initialised yet