It is a PC Clock synchronization program. It is alternative solution to synchronizing with atomic clock using NTP(SNTP) and Internet. The program works in the interactive mode or in background. The program can be used as NMEA and COM port tester. It outputs a port receiving buffer, extracts all NMEA sentences and counts check sum errors. The product is free for users of Atomic Clock Service, PC Atomic Sync and OS Non-Proxy Atomic Sync.