There's good reason why Run mode memory depth is managed, to retain high throughput and reduce blind time.
Step back a minute and think about it... what is the scope doing when you are in split screen zoom mode? You have the zoom area at your target resolution and its buffering the rest of the data so you can zoom out and see more if you choose
Now... what is wanted is the ability to be at your target resolution but be able to change your timebase to zoom out but without actually 'activating' zoom mode. How do you do this? Activate zoom mode and hide the horizontal scroll bar, remove other zoom UI components. Now what happens when someone changes to a higher timebase? it zooms out because it has the buffered data from someone saying they want more memdepth at a lower timebase...
Like i keep saying.. this is all UI illusion bits now with just how people want to use it.. it already has the power to do it because... IT ALREADY DOES IT! Less for some weird reason that wouldn't work? I cant think of one anyway to fret over so really its just waiting for someone to prioritize such a thing and build the UI out for it as a second layout for zoom mode
Omg
Whole solution need only one toggle push button without even need add any more HW buttons. In "normal" split window zoom mode just push this button and zoomed window is full screen and next back to split screen zoom display push again this button.
Again, simplest solution can solve it least as baseline solution and whole mess and <censored> around this thing is gone....
Siglent: Do It! Now! Or better - yesterday.
--------------------------------------------------------------------
Common sidenote to wfm history buffer:
Btw there seems live some rumors that when it do short acquisitions using faster timebases then it use rest of acquisition buffer memory for normal runtime history. No, it is not limited to amount of acquisition memory length least in some Siglent models. Example in some SDS1000 models maximum history buffer can have over 100M data points when max acq memory length is specified for 14M or example 4x7M. Same for fast sequence mode aka "segmented memory acquisition". Why it is not called using this historical name - because it is not limited to divide normal acq. memory to segments as in historical some scopes. So it is just sequence mode. (it can use also more slow internal free memory than just fast acquisition memory because there is time to push these "segments" to other free memory places what memory places are not at all usable to max continuous acquisition memory length.
I do not remember how this same thing is arranged in R&S some RTO models who is or have been perhaps one leader in this - runtime always background working history buffer principle - but no dogs are barking.
Who can check what is max amount of history buffer data in Siglent 2000X Plus
Something like in this table what I made time ago, not need whole table but even with some different settings so we can see do it still exceed normal acq. memory max length. Of course better place for this is other thread about this Siglent model.
Just wish to Siglent. Do NOT change this principle how it is now, continue Siglents own road - when dogs are barking they know they get food (mediabusiness is...)!
But "side" features you can ADD as example just said, based to @elasia comment, solution and it can also develop and implement so it works nice and robust. How solution can be so simple... just behind corner. (do it so that also mediabusiness peoples can understand it when they do DTFTLIE method) - simple solution and it works and you get two bird using one shot.
(DTFTLIE = Do (Test || Things) First and Think Later If Ever)