INT 21 U - IBM SYSTEM 36/38 WORKSTATION EMULATION - VDI.SYS - GET ???
        AX = 4402h
        BX = handle for character device "GDMS"
        CX = number of bytes to read (>= 4)
        DS:DX -> buffer (see below)
Return: CF set on error
            AX = error code (see AH=59h)
        CF clear if successful
            AX = number of bytes read

Format of returned data:
Offset  Size    Description
 00h  4 BYTEs   ???
 04h    DWORD   pointer to ???
 08h  4 BYTEs   ???