Two changes are made in this checkin.

Two changes are made in this checkin.
The first is a change to force the console to stay 8N1, the configuration
of the bug/prom during the first open to the device by init.

The second is to not enable interupts until the port is opened. Previously
receive and CD change interrutps were enabled at config time. If a
character arrived before the port was opened for the first time, it
would crash the system.