10BASE-5 is the original Ethernet system. It employs a quarter of an inch diameter, 50 ohm coax cable ( with minimum bend radius
of 10 inches). 10BASE-5 segments can run in length up to 500 meters with as many as 100 transceiver connections
spaced at lease 2.75 yards apart.
10BASE-5 transceivers access the media by piercing the thick coaxial cable. These transceiver taps are known as vampire taps. Since
they don't actually require breaking the physical cable, the electrical signals over the cable are typically fairly clean.
10BASE-5 systems were originally envisioned to be cheap and fairly easey to build. The large cable needed simply to be run by rooms
where computing equipment would be located. Taps would be made into the cable by using external transceivers. As it turned out, the
requirement of an external transceiver and the thick cable, which was expensive and difficult to work with, limited the use of 10BASE-5.