bueno con un for podria ser asi
procedure TForm1.Button1Click(Sender: TObject);
var
x:byte;
cad:string;
begin
cad:=Edit1.Text;
Edit1.Clear;
for x:=0 to length(cad) do
begin
Edit1.Text:=Edit1.Text+uppercase(cad[x]);
end;
end;
o tambien Edit1.Text:=uppercase(Edit1.Text);
