MDI is documented in the following:
Network drivers that use other media types can be implemented with the DLPI messages that are documented on the Section D7dlpi manual pages. Drivers that use the SCO UnixWare 2.X DLPI interface cannot be built on UnixWare 7 systems, although most existing drivers will run on UnixWare 7. Support for SCO UnixWare 2.X DLPI drivers will be dropped in the next major release of the operating system.
The MDI interface versions for UnixWare 7 and SCO OpenServer are quite similar, although the UnixWare 7 version supports more functionality than the SCO OpenServer version does. Most modifications required when porting MDI drivers between the two platforms are related to the differences between the basic driver interfaces on the two platforms: differences in the entry point routine sets, the synchronization primitives that are supported, and the configuration facilities that are used. See ``Porting network adapter drivers to MDI 2'' for more information about porting MDI drivers between SCO OpenServer and UnixWare 7 systems.