A test and measurement instrument includes a first input port and a second input port that receive a first input signal modulated according to a first clock signal and a second input signal modulated according to a second clock signal, respectively. The first clock signal and the second clock signal may be asynchronous. The instrument also includes a phase reference that generates clock data for the second clock signal. The instrument includes a processor that determines time bases for the input signals that comprise different rates based on the received and/or generated clock data. The instrument also includes a display coupled to the processor. The display concurrently displays the first input signal in a first graticule according to the first time base and the second input signal in a second graticule according to the second time base.