How to control GPIO?

Hi,

I'm using the STM32F103ZE uC on the MCBSTM32E development board.
I tried the example programs, they all compile and download and run fine, but they are NOT SIMPLE. They use a lot of Library files etc, etc, etc.
I just try to make some ports go high or low.

The example GPIO program states:
- Enable the clock signal for the GPIO.
- Configure the Alternate Function to use a GPIO (usually standard after reset).
- Configure the GPIO pins as input or output.
- Set remaining parameters like speed, pull-up/down.
- Enable the GPIO.
- Read from or write to the GPIO.

Can someone give me a simple (and I mean REALLY SIMPLE) program to control just one single GPIO port?

My questions to activate some port:
- do I need something to know about internal clock signals?
- do I need some startup file?

Thanks,

Henk