INT 2F - PCED/ASSOC - INSTALLATION CHECK                                        
	AX = 48C5h
	BL = 00h
Return: AX = 0000h if installed
	    BX = ASSOC resident segment
Program: ASSOC is a resident utility included as part of the PCED package which
	  associates files with executable programs based on their extensions
Note:	chains if BL > 02h on entry
SeeAlso: AX=48C0h,AX=48C4h,AX=48C5h/BL=01h,AX=48C5h/BL=02h