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)
Note:   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

See also: 13A0

25 - PC-CACHE.SYS - INSTALLATION CHECK