Once again, thanks for the information. I read the posts and their individual links and tried to copy those techniques as much as possible.
I ran GPSMAPSerieswithSDCard_20170825.exe which placed GUPDATE.gcd and the folder “updates” on a blank card. I placed it in the machine and held the power button down until “Transferring to Recovery Region” appeared. I released the power on button at this point. After 15 or 20 seconds, the machine started the update process which still ended with software version 11 still installed.
I noticed in message #11 that GUPDATE.gcd is the only file that should be on the card, no “updates” folder. I tried this, but nothing would happen until the “updates” directory was returned.
Also, I’m wondering if running GPSMAPSerieswithSDCard_20170825.exe is what I’m supposed to be doing. I’m getting the impression that files are supposed to be extracted from the executable which is probably way beyond my skill set.
Thanks again!