37 pins of GPIO with an external D-Sub connector, plus DAC/ADC with Libraries built in to the OS. https://www-s.acm.illinois.edu/bug/Be%20Book/The%20Device%20K

37 pins of GPIO with an external D-Sub connector, plus DAC/ADC with Libraries built in to the OS. https://www-s.acm.illinois.edu/bug/Be%20Book/The%20Device%20Kit/GeekPort.html https://www-s.acm.illinois.edu/bug/Be%20Book/The%20Device%20... http://www.hardwarebook.info/GeekPort http://www.hardwarebook.info/GeekPort