I’ve just noticed he said “an arbitrarily fast mind running in a human body”, not an actual human being, so I don’t think it would be much slower at typing uuencoded compressed stuff than natural language (at least with QWERTY—it might be different with keyboards layouts optimized from natural language such as Dvorak, but still probably within a factor of a few).
The 120WPM is pretty good for the physical limits: if you are typing at 120WPM, then you have not hit the limits of your thinking (imagine you are in a typing tutor—your reading speed ought to be at least 3x 120WPM...), and you’re not too far off some of the sustained typing numbers in https://en.wikipedia.org/wiki/Words_per_minute#Alphanumeric_entry
I’ve just noticed he said “an arbitrarily fast mind running in a human body”, not an actual human being, so I don’t think it would be much slower at typing uuencoded compressed stuff than natural language (at least with QWERTY—it might be different with keyboards layouts optimized from natural language such as Dvorak, but still probably within a factor of a few).
The 120WPM is pretty good for the physical limits: if you are typing at 120WPM, then you have not hit the limits of your thinking (imagine you are in a typing tutor—your reading speed ought to be at least 3x 120WPM...), and you’re not too far off some of the sustained typing numbers in https://en.wikipedia.org/wiki/Words_per_minute#Alphanumeric_entry
My point was that 1 bit per character is an underestimate.