INT 25 - PC-CACHE.SYS - INSTALLATION CHECK                                      
	AL = FFh
	SI = 4358h
Return: SI = 6378h if installed
	    CX = segment of device driver PC-CACHE.SYS
	    DX = version (major in DH, minor in DL)
Program: PC-CACHE.SYS is a small device driver used by PC-Cache v5.x to obtain
	  access to certain disk drivers for devices such as Bernoulli drives
SeeAlso: INT 13/AH=A0h