Steren CAL-150 Instructivo De Uso página 189

Negative numbers is binary, octal, and hexadecimal will be
displayed as two complements.
In order to distinguish letters A, B, C, D, E, and F used in
hexadecimal mode, they will be displayed as shown in the
following chart
Binary:
Octal:
Hexadecimal:
Positive
Negative
Positive
Negative
Decimal
Positive
Negative