The RGB signals for PC monitors are driven through coaxcables whose characteristic impedance is 75 Ω. The graphicschip will generally have current-source output drivers that shouldbe double terminated with a 75 Ω shunt termination at each end.On the transmit end, the shunt terminations are provided toground close to the graphics IC, while the monitor terminatesits end via internal termination resistors. While this scheme workswell and is virtually foolproof for a single monitor, it leaves nomeans for passively connecting a second monitor to the same source.