IBM 9729 optical wavelength multiplexer - (PWJ94)

Some computer networking technology from the 1990's. The IBM 9729 optical wavelength division multiplexer is a device that combines 20 bi-directional data streams (Ethernet, FDDI...) into one fibre. And takes it apart at the other end of the fibre back into the original 20 data streams. Sounds complicated? It is..... :-) More information about WMD's: http://spie.org/newsroom/history-and-technology-of-wavelength-division-multiplexing?ArticleID=x22960&SSO=1