DSO Quad suggestion and bugs.

Hi!
DS0230 after calibration in all range, given invalid value in Vdc, real value = 3.2 Vdc=2.80.
may by DS not uses callibration data, same marker “zero line” then display shifting up or down from channel marker then callibration work on real value, and not sift line the calibration performed only GND

the add by ideas:
-the ability to view and values ​​korrektiroyvki salibrovki without recalibration of choosing from the menu