)
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
SeeAlso: #02651,#02653