Is there any waveform monitor that can display channel A – B subtraction like what was available in the 1480?

Is there any waveform monitor that can display channel A – B subtraction like what was available in the 1480?

Yes. The VM700T has a built-in channel subtraction mode which would allow you to subtract two channels in either the waveform mode or the vectorscope mode while retaining all of the other measurement capabilities of these modes such as select line, cursors or any of the standard analog measurements the VM700T can make. To access this mode, simply press any channel source button on the VM700T while simultaneously holding down another channel source button. When this is done you should see the light on the button you held down remain steadily on while the light on the button you pressed blinks. The blinking channel will now be subtracted from the solid channel in the waveform and vector modes.

Another possibility is to use a 1760 series waveform monitor in the bowtie mode. The bowtie mode was never really designed for this purpose but technically, while looking at the bowtie display, the left side will show A-B and the right side will show A-C regardless of whether those signals are component or composite or even contain the bowtie test signal. Therefore you could connect two composite signals and get a waveform subtraction of them.