There is a tendency at some places to not rip out old cables when putting in new. I have seen in some buildings at NASA Goddard a few runs of old 10Base5 cable

There is a tendency at some places to not rip out old cables when putting in new. I have seen in some buildings at NASA Goddard a few runs of old 10Base5 cable with vampire taps still in place. I should grab one as a souvenir of the old days. I've also found various adaptors and old switches that could bridge a 10Base5 to 10Base2 network. The 15-pin connectors at the ends of the MAU cables were designed to be used vertically, with a latching mechanism to hold it in place. Many Unix workstations mounted the socket horizontally on the motherboard and in that orientation the latch didn't really work. This created all sorts of reliability problems.