Hi,
I have done this many times before, I don't know if the error is coming from the site or if it means something is amiss with my system.
I just today installed Ubuntu Mate 16.4.3 onto USB and ran an update.
Than in a terminal, I ran:
sudo add-apt-repository ppa:dansmith/chirp-snapshots
and I get the error:
input output error
 
and the PPA isn't added.
Any thoughts?
 
 
 
Lenny/Glenn/N0YJV
 
"Was the government to prescribe to us our medicine and diet, our bodies would be in such keeping as our souls are now."
Thomas Jefferson
 
“Happiness depends more on the inward disposition of mind than on outward circumstances.”
Benjamin Franklin