Turns on networking in FMSLogo. This must be called before any other network commands will work.
synchronous_dns input is not given, FMSLogo uses asynchronous DNS.
You may optionally call NETSTARTUP with the
synchronous_dns input as 0 (asynchronous) or 1 (synchronous).
Synchronous DNS makes FMSLogo unresponsive during a network name lookup.
Support for synchronous DNS was added to work around "Host not Found" errors with Trumpet WinSock in the early 1990s.
It should not be needed today.