Thank you again Alex for the above and beyond help!
1. I reset tty and grub.conf to original values by restoring the SD card with the Linux SD card image provided via Intel.
2. I connected the shield to my terminal and separately connected the 3.5mm stereo jack to my windows USB port, observed the boot process in PuttY and reached the Linux prompt.
3. I attempted the initialization commands. "echo -n 40 > /sys/class/gpio/export resulted in a failure, device in use. I was able to run echo out > /sys/class/gpio/gpio4/direction and echo 1 > /sys/class/gpio4/value. Question: Are these gpio modification required to properly activate the RS-232 cutedigi shield on Galileo such that communication is possible?
4. When I run the echo test to ttyS0, a small LED on the RS-232 briefly illuminates, it suggests signal is going to the RS-232 shield board. I also (previously, and separately) ran an Arduino sketch issuing writeln commands to serial1 with a 1 second delay and observe the RS-232 shield tiny green LED blink once per second, suggesting my code is running and signal is getting that far.
5. I attempted both straight and null modem cables. I validated 9600 8N1 on both Linux and the terminal machine.
Perhaps it's not the Galileo per se, maybe the problem is the cutedigi RS-232 shield and its operation with Galileo. My terminal, a 1978 era DEC Writer III, connects perfectly to either my Mac or Windows with a serial to USB converter cable. Yet somehow with the cutedigi RS-232 shield mounted on the Galileo, it's not achieving any evidence of connection. I don't have a scope so not sure how to diagnose or what to try further.
thank you,
John
