what is the purpose of Port D (PD7..PD0) on the atmega8L chips?

[Borot]

What is the function of Port D (PD7..PD0) on the atmega8 chips used on the 50 dollar robot ? I read that they are an i/o port with a pull up resistor, but for someone who's new to chip function what does it do when the led resistor power indicator circuit is connected?

[Pierre]

On the $50 robot Port D on the ATmega8 are digital I/O and used for the servo output for the robot.  Later you can UART by using PD0(RX) and PD1(TX).

$50 robot tells you about Port D and there is a tutorial for the UART.

Have fun