Marathon Computer UNIPRO V3.5 - Manual (Page 169)

MMI Product Documentation
Unipro 3.5 Process Control 1 Aug. 1997
the [Up Arrow] or [Down Arrow] key will
change the calibration value by a thousand
units. The middle digits will show sensitivities
of a hundred and ten units respectively. It is
not important to know the relative worth of
one calibration unit. Understanding that the
location of the flashing digit affects change that
one key press will make on the calibration
value is necessary. By observing the degree of
sensitivity one key press makes at each flashing
digit location, you can quickly see how to use
this feature.