In the 1994 book "Pulsars" edited by G. Srinivasan and published by the Indian Academy of Science, Prof. Joseph Taylor discusses how there are several binary pulsar systems now known:
PSR 1913-16 the famous one! PSR 1534+12 PSR 1802-07 PSR 1855+09 PSR 2127+11 PSR 2303+46Only PSR 1534+12 has been 'timed' well enough and long enough to provide a test for general relativity. It was discovered in 1991 and discussed by Aleksander Wolszczan ( Nature vol 350, p. 688) and it promises to surpass even PSR 1913+16 after enough data has been accumulated.