triple combine key not responding

Using Arduino Programming Questions
#1

Hi gus.

I’m using a sparkfun pro micro to simulate a keyboard and this is the code.

const int pin[3] = {5,6,7};
int array[3] = {0x80,0x81,0xD4};
int i = 0;

void setup()
{
  for (i=0;i<3;i++)
  {
    pinMode(pin[i],INPUT);
  }
  Keyboard.begin();
}

void loop()
{
  for (i=0;i<3;i++)
  {
    if(digitalRead(pin[i]) == HIGH)
    {Keyboard.press(array[i]);}
    else
    {Keyboard.release(array[i]);}
  }
}

The problem is, CTRL+SHIFT+DELETE is not working.

I tried to replace 0xD4 with ‘a’, SHIFT+A and CTRL+A work.

the schematic is nothing special that three input pins goes with three pull down resistors.

#2

A look at the keyboard library pages tells me only some 2 key combos are supported.

#3