Accented Greek capitals.

Accented Greek capitals.

Ones with tonos put the accent to the left of the letter rather than
above it, which makes for a rather squashed Omega.  In real teletext,
the tonos is put in the character cell to the left, but I don't know
if that can be coded in Unicode properly.  Maybe I need a silly
multiple substitution for a space followed by an capital with tonos.