II Morrow Inc. 50 User Manual page 180

Message Function
CLOSE Altitude
This condition occurs when the airspace boundary is
within 500 feet, or a user-selected limit in the System
function.
INSIDE
This condition occurs when the plane penetrates the
airspace.
Empty TO Waypoint: Cannot Compute Nav
Anytime the current To waypoint is empty, this
message is generated. It becomes an old message after
viewing.
GPS Self Test Failure
If the GPS self-test fails, a message displays indicating
the cause of the failure in four hexadecimal digits. It
becomes an old message after viewing.
8-4
Within 500' of
NORTON AFB
Class C
Inside of
SAN DIEGO
Class B
Empty To Wpt:
Cannot Compute
Nav Info
GPS Self Test
Failure: 1FFF
Service Needed