INT 2F U - CDBLITZ v2.11 - INSTALLATION CHECK                                   
	AX = 1500h
	CH = 90h (function number)
	BX = 1234h (magic value for CDBLITZ)
Return: CX = 1234h if installed
	    CF clear
	    DX = BCD(Binary Coded Decimal) A method of data storage where two decimal digits are stored in each byte, one in the upper four bits and the other in the lower four bits.  Since only the values 0 through 9 are used in each half of a byte, BCD values can be read as decimal numbers on a hexadecimal display of memory or a file. version number (DH = major, DL = minor)
Program: CDBLITZ is a CD-ROM cache by Blitz 'n' Software, Inc.
SeeAlso: AX=1500h/CH=99h