Hi, thank you for the explanation.
In Psychtoolbox (with latest update), there are some functions to deal with the non-Latin-1 input issue as below.
Ask/GetString/GetEchoString/GetCharTest: Deal with Unicode key input. This now allows to take input in character sets / from keyboard layouts other than US layout with ASCII/Latin-1. E.g., german umlauts etc. should be processed properly. Only tested on Linux, but hopefully works on Windows/macOS as well.
I am not sure that the compiled binary from Psychtoolbox also contains GetString function.