[plt-scheme] encoding: latin1 and utf

Hi,

how can I use latin1 strings with plt scheme 299.100? If I put something
like:

 (display "não\n")

I get:

bytes->string/utf-8: string is not a well-formed UTF-8 encoding: #"(display \"n\343o\\n\")"

[I have no intention of using utf-8]

Thanks in advanced,

Pedro Kröger