Not the best way, but if you're only entering numbers, try this. In the top of serial monitor, enter 127,128,0,1[ENTER].
void setup()
{
Serial.begin(9600); // set line end to Newline at
// bottom of serial monitor
}
void loop()
{
int x, y, bs1, bs2;
x = y = bs1 = bs2 = 0;
while(Serial.available() > 0)
{
x = Serial.parseInt();
y = Serial.parseInt();
bs1= Serial.parseInt();
bs2 = Serial.parseInt();
char r = Serial.read();
if(r == '\n'){}
Serial.print("x = ");
Serial.println(x);
Serial.print("y = ");
Serial.println(y);
Serial.print("bs1 = ");
Serial.println(bs1);
Serial.print("bs2 = ");
Serial.println(bs2);
}
}