The user interface is pretty sparse. Incoming IRC messages are printed,
and your input line is marked by the regular Atari cursor. Text you
enter is displayed in inverse video. If IRC messages are received while
you're entering an input line, they're printed correctly without being
intermixed with your input.

The Atari character set lacks some commonly used ASCII characters. Most
noticeable on IRC is the ~ (tilde). FujiChat prints an inverse-video ^
(circumflex) instead. Also missing are { and } (curly braces). These
are printed as inverse-video [ ] (square brackets). There is currently
no way to type the ~ { } characters!

Non-ASCII (Unicode/UTF-8) characters are not decoded. Generally these
print as inverse capital B followed by another inverse video character
(these are the raw UTF-8 encoded bytes).

There are a few keyboard commands available. Normal Atari editing doesn't
work (cursor keys, crtl-insert, etc). The maximum input length is 256
characters: if you try to type more than that, the bell will ring,
and further keystrokes (other than Enter or backspace) will be ignored.

At the start of an empty line:

  Control-N: shows list of users on the current channel (same as
             the /names command).

  Control-W: shows more detailed list of users on the current channel
             (same as the /who command).

  Tab: inserts "/msg user", where user is the last user you received
       a private message from.

In the middle of a line:

  Shift-Delete or Control-U: delete the line you're typing.

  Control-W: delete the last word you typed (back to and including
             the last space, or to the start of the line if there's
             no space).

  Backspace: delete the last character typed, as usual.