I was one of the lucky purchasers of the HP service 42S calcs.
I am still getting used to seeing both X and Y values (after 30 years of keeping Y in my head).
On my model, the values are displayed against a matrix or grid (for want of better words) of LCD dots. If I adjust the contrast of the display, the relative intensity of the background versus the numbers does not change much. I find this background rather annoying, and don't see any logical reason for its presence.
Is there some way to get rid of this background? (The service calcs did not come with any manual(s).)