Bay Networks NauticaRS Reference Manual page 404

NauticaRS 5.5R Reference Guide
12-8
In the next example, a mask of 96 has been entered. The
mask specifies that we are checking positions 8 and 1 in
the first half of the byte and positions 4 and 2 in the
second half:
Using this mask, we want to match a 1 in position 8 and
a 0 in position 1 of the first half of the byte and a 0
against position 4 and 2 in the second half. The value
entered here (in hexadecimal) is 80.
117237-E Rev.00