Int 21 Fn 2B  - Super PC-kwik V3.20+ - Installation Check                  [c]

   AH = 2Bh
   CX = 4358h ('CX')

Return: AL = FFh if PC-Kwik/PC-Cache not installed
   AL = 00h if installed
       CF clear
       CX = 6378h ('cx')
       BX = ???
       DX = version (DH = major version, DL = binary minor version)

Note:  PC Tools PC-Cache v5.x and Qualitas Qcache v4.00 are OEM versions of
     Super PC-Kwik, and thus support this call (PC-Cache 5.1 corresponds
     to PC-Kwik v3.20)

See Also: INT 13/AH=A0h,INT 13/AH=B0h,INT 16/AX=FFA5h/CX=1111h
Index: PC-Cache;installation check|Qualitas Qcache;installation check
Index: installation check;PC-Cache 5.x|installation check;Qualitas Qcache