I have a feeling that it isn't computer memory as such as truncating a flight level that was above what some software designer for the En-Route Automation Modernization (ERAM) system thought was possible. Imagine the chaos if the system had dropped a zero and called it 6000 feet. All those short term conflict alerts with the low altitude aircraft
. STCAs are really really bad for controllers to get as they alert the supervisors that a controller has lost separation
. And all the time the controller had nearly 9 miles vertical separation.
It will be interesting to find out what happened from someone who knows the ERAM software.