Arduino Micro Serial1

[abc1]

Hello, I'm trying to use an arduino micro to communicate using the serial pins rx/tx.
To test the communication connected pins rx/tx to a serial to USB adapter and run this code:

/*
  TEST SERIAL0 (USB) e SERIAL1 ( RX/TX PINs)
*/
int IntTesto = 0;
char CharTesto = 33;


void setup() {
  // initialize serial communication at 9600 bits per second: Standard 8-N-1
  Serial.begin(9600, SERIAL_8N1);
  Serial1.begin(9600,SERIAL_8N1);
  delay(1000);
}


void loop() {

  IntTesto = 0;
  for (int i = 0; i <= 50; i++) {
    Serial.print(IntTesto);
    Serial1.print(IntTesto);
    delay(300);
    IntTesto = IntTesto + 1;
  }
  Serial.println();
  Serial1.println();
  CharTesto = 33;
  for (int i = 0; i <= 64; i++) {
    Serial.write(CharTesto);
    Serial1.write(CharTesto);
    delay(100);
    CharTesto = CharTesto + 1;
  }
  Serial.println();
  Serial1.println();
}

Everything works well with the USB port but monitoring the serial port only produced gibberish characters

Anyone can help me out?

Thank you.