Wait, if the default -:t setting could be changed from "1"("A"?) to "8" with the motivation that that would make it friendlier out of the box,

what would the implied worst-case be, for instance on a 0..255 only terminal?


So the -:t setting affects both console IO (print read-line etc.) and REPL IO (the Read step).

(
I guess the implied worst-case for the current "1"("A"?) default is

 * If the terminal is UTF-8 only: Trashing of input of >=128 characters, e.g.

gsi
> (string->list "ü")
(#\xc3 #\xbc)

   (REPL left-right input behavior when attempting to input them is messed up but that could maybe be fixed.

    Non-escaped output of the trashed input has an "untrashing" effect which can conceal the trashing problem, but that is intended, as in that the ISO-8859-1(&ASCII?) coder has a 1:1 byte to char mapping, and also showing the same with escaped output immediately shows the problem e.g. "\303\274" for what should have been "\374".)

 * Scary error messages when trying to output unicode chars

> (print (make-string 1 (integer->char 1234)) "\n")
*** ERROR IN ##write-substring -- Can't convert to C ISO-8859-1-string
(write-char #\u04d2 '#<input-output-port #2 (console)>)
1>
)