Mars seismic data obtained by Viking Lander 2 mission in 1970's are released from DARTS. The original data were processed by UTIG and MIT independently. Therefore, there have been two different datasets in the world from the same measurement. The UTIG processed data were sent to ISAS together with the Apollo seismic data. The MIT processed data have been archived at NSSDC, which, unfortunatelly, do not seem to be widely used. At DARTS, we provide both datasets with technical description. To validate them, we have compared the two versions of the datasets. As a result of the comparison, they are found to be essentially identical, although formats are different. For instance, the famous figure published in the old report "Seismology on Mars" in 1977 (right, top) can be newly re-constructed using the MIT version of the data: DD030692_F3/8260, 8270, 8280, 8290, 8300