in reply to Re: SerialPort issues under Windows 10
in thread SerialPort issues under Windows 10

Aha! write_settings was the key step I think - I naively thought that was just to write settings to a file, rather than initiate the settings described!

Many thanks all.

Will try and remember strict and warnings... Have had a bug in the last several years of occasional scripting where that might have been useful, in retrospect. Old habits etc...