I assume that there is an analog anti-aliasing filter that matches the sample rate. But how is the anti-aliasing filter realized when sampling at a lower rate? Does the ADC always run at full speed and the anti-aliasing and resampling is done digitally or is there a bank of switchable analog filters? If it is done digitally (which I would assume), is it done in real-time or via post-processing? Again I would assume it is done in real-time otherwise one would need a lot of memory for low sampling rates.
Do all scope modells also from other series implement the anti-aliasing filter the same way or are there differences?