Well, the original pdf page size is 3.54 x 4.72 in (diagonal: 5.9 in, aspect ratio: 0.75, like 600 x 800 px).
For the moment, it really seems to me that there's no way to "solve" my problem directly in M92.
So, I created a re-arranged PDF file.
There are now 4 "small" old pages (organized as 2x2) on one "big" new page.
On the big M92 screen this new file can be read quite comfortably in the "portrait" orientation (although the characters are a bit too small for my taste).
Now, I would like to get this new file working in the "landscape" orientation.
Well, I need a magic sequence of option settings to do it ... I can "rotate" the screen ... but then I cannot find any option to customize the zoom to exactly the half of the height of the pdf page ... so that at first I see the upper 2 "small" old pages (upper "row" of my new file) and then it should nicely switch to display the lower 2 "small" old pages (lower "row" of my new file). Of course, I realise that it will not use the whole width of the screen, but I don't care (actually it should use almost the whole width).
Thanks in advance,