It appears that somewhere along the way, the IDE switched from an 8-bit ASCII code to a 16-bit Unicode system. As such, you need to print both bytes with no intervening characters. Try this:
void setup() {
Serial.begin(9600);
for (int i = 128; i < 256; i++) {
Serial.print(i);
Serial.print(" ");
Serial.write(0xC0 |(i >> 6)); // Notice Serial object uses write()
Serial.write(i & 0x3F | 0x80);
Serial.println();
}
}
void loop() {
}
You'll note that code 167 is not the Unicode for the degree symbol; 176 is.