I just took another look at getting this ported.
I was able to verify that the LED address that was already discovered earlier is correct. This script:
https://chdk.fandom.com/wiki/Canon_Basic/Scripts/MMIO_LED_Blinker works unmodified (the address is 0xd20b0994). It blinks the tiny green LED near the wheel which is near the func set button, not the bright auto focus assist LED.
Having this verified is very helpful because my next goal would be to try getting the camera to blink the led by building something with the CHDK code. I'm planning to take Reyalp's advice and start from scratch and use Ghidra when needed.
One interesting thing about Canon Basic for this camera is that the hello world scripts don't seem to display anything. Maybe I'm just doing something wrong or they flash on the screen too quickly? Either way I'm happy that scripting works at all. I was also able to run the FIRMINFO.TXT script but I didn't see anything helpful in the information in that file except maybe the firmware version which I already know.
