Complex sentence: The DIDS system was never implemented, partly because it was too expensive and partly due to it being a one way system with nothing going up the line, the job of attack warning in the US remained with the EBS (now the Emergency Alert System).
Split into simpler sentences: The DIDS system was never implemented, partly because it was too expensive and partly due to it being a one-way system with nothing going up the line. The job of attack warning in the US remained with the EBS (now the Emergency Alert System).