*** The command C-x RET m (toggle-enable-multibyte-characters)
turns multibyte character support on or off for the current buffer.

If multibyte character support is turned off in a buffer, then each byte is a single character, even codes 0200 through 0377--exactly as they did in Emacs 19.34. This includes the features for support for the European characters, ISO Latin-1 and ISO Latin-2.

However, there is no need to turn off multibyte character support to use ISO Latin-1 or ISO Latin-2; the Emacs multibyte character set includes all the characters in these character sets, and Emacs can translate automatically to and from either one.