The regulator should be marked K850(5.0V) or K833(3.3V).

The 16MHz resonator may be marked with "A1" or "A'N"
The 8MHz resonator may be marked with "80'0"

As others have indicated, you can apply up to 12V at the RAW pin, and measure the output of the regulator.

The regulator should be marked K850(5.0V) or K833(3.3V).

A 5 volt part has a 16MHz resonator may be marked with "A1" or "A'N"
A 3.3 volt part has a 8MHz resonator may be marked with "80'0"

As others have indicated, you can apply up to 12V at the RAW pin, and measure the output of the regulator.

The regulator should be marked K850(5.0V) or K833(3.3V).

The regulator should be marked K850(5.0V) or K833(3.3V).

The 16MHz resonator may be marked with "A1" or "A'N"
The 8MHz resonator may be marked with "80'0"

As others have indicated, you can apply up to 12V at the RAW pin, and measure the output of the regulator.