I am trying to utilize the GPIO pins on Port G for controlling some external peripherals.
I have written a library to provide access to all GPIOs for this purpose.
I also have written a PeekPoke utility to allow me to manipulate the internal peripheral registers of the A400 for test.
We will not be using PCMCIA of CF devices on this platform and have not included the drivers in our environment.
I enable Port G for GPIOs by setting the PCMCIACON register PCEN12 (bits 1 and 0) to zero. Further, for debugging, I ensured that the Port G GPIOS were set as inputs at this time.
Once I have disabled PCMCIA, I then set the Port G pins to be outputs but initially all high.
I can manipulate all of the 8 GPIO pins to be high with no ill effects. I can manipulate pins 0,3,4,5,6,7 to be either High or Low, but if I set G:1 or G:2 low, the touch screen stop functioning.
I have looked at the schematics for both the card engine and development kit and can see no connection between these.
Is there some use of the Port G pins for touch panel that I do not see?
Since I only need 5 pins for my peripherals, I will plan to move all 5 signals to pins 3,4,5,6,7 for now.

Rich