INT 2F - Lotus CD/Networker - INSTALLATION CHECK
        AX = D000h
Return: AL = FF if CD/Networker TSR is loaded
        BX = 4D44h ("MD") signature
        CX = Windows mode word (from INT 2F/AX=1600h) at time of TSR load
        DX = bitmap identifying all loaded CD/Networker TSRs.
Notes:  INT 2F/AH=D0h is used by CD/Networker to communicate between a
          resident redirector TSR and a transient program that controls the
          TSR's CD-ROM drive emulation (volume attachments, caching, etc).
        At present there is only one CD/Networker TSR; the bitmap always = 4.
SeeAlso: INT 2F/AX=1500h"CD-ROM"