Int 2F Fn 1684  P - Ms Windows - Vcd - Get Api Entry Point                 [W]

   AX = 1684h
   BX = 000Eh (virtual device ID for VCD device) (see #2329)
   ES:DI = 0000h:0000h

Return: ES:DI -> VxD API entry point (see #2339)
         0000h:0000h if the VxD does not support API in current mode

See Also: AX=1684h"DEVICE API",INT 20"Windows"

(Table 2339)
Call VCD entry point with:
   EDX = function number
       0000h get VCD version

       Return: CF clear
           AH = major version
           AL = minor version
       0001h get ???

       Return: CF clear
           AX = bit mask of ???
       0002h get ???
       CX = COM port number

       Return: CF clear
           DX:AX -> ???
       0003h set ???
       CX = COM port number
       DX:AX -> new ???

       Return: CF clear
       0004h acquire COM port
       AX = ???
       CX = COM port number

       Return: CF clear
           AX = ???
           EBX = ???
           DX = ???
       0005h release COM port
       CX = COM port number

       Return: CF clear
       0006h ???

       Return: CF set
           AL = 00h
       else

       Return: CF set
           EAX = FFFFFFFFh

Note:  these functions are apparently only available from the system VM,
     returning CF set and EAX=FFFFFFFFh otherwise

See Also: #2338,#2340