if line.dataB == nil or #line.dataB == 0 then

--?   if line_index == 8 then print('checking for B side') end
  if line.dataB == nil then

--?     if line_index == 8 then print('return 1') end

--?     if line_index == 8 then print('return 2') end

--?   if line_index == 8 then print('drawing B side') end

--?   if line_index == 8 then print('a') end

--?     if line_index == 8 then print('b') end

--?       if line_index == 8 then print('c', State.cursor1.line, State.cursor1.posB, line_index, pos) end

  Text.populate_screen_line_starting_posB(State, State.cursor1.line)

  local x = Margin_left + Text.screen_line_width(State, State.cursor1.line, #line_cache.screen_line_starting_pos) + AB_padding
  Text.populate_screen_line_starting_posB(State, State.cursor1.line, x)

--?   print('to2:', State.cursor1.line, State.cursor1.pos, State.cursor1.posB)

  top2.screen_pos = 1  -- start of screen line

--?   print('to2: =>', top2.line, top2.screen_line, top2.screen_pos, top2.screen_lineB, top2.screen_posB)
  -- slide to start of screen line
  if top2.screen_pos then
    top2.screen_pos = 1
  else
    assert(top2.screen_posB)
    top2.screen_posB = 1
  end

  local line_cache = State.line_cache[loc1.line]

  for i=#State.line_cache[loc1.line].screen_line_starting_pos,1,-1 do
    local spos = State.line_cache[loc1.line].screen_line_starting_pos[i]

  for i=#line_cache.screen_line_starting_pos,1,-1 do
    local spos = line_cache.screen_line_starting_pos[i]

  Text.populate_screen_line_starting_posB(State, loc1.line)
  for i=#State.line_cache[loc1.line].screen_line_starting_posB,1,-1 do
    local sposB = State.line_cache[loc1.line].screen_line_starting_posB[i]

  local line_cache = State.line_cache[loc1.line]
  Text.populate_screen_line_starting_pos(State, loc1.line)
  local x = Margin_left + Text.screen_line_width(State, loc1.line, #line_cache.screen_line_starting_pos) + AB_padding
  Text.populate_screen_line_starting_posB(State, loc1.line, x)
  for i=#line_cache.screen_line_starting_posB,1,-1 do
    local sposB = line_cache.screen_line_starting_posB[i]

    print('a')

--?     print('a')

    print('b')

--?     print('b')

      print('c1', loc2.line-1, State.lines[loc2.line-1].data, '==', State.lines[loc2.line-1].dataB, State.line_cache[loc2.line-1].fragmentsB)

--?       print('c1', loc2.line-1, State.lines[loc2.line-1].data, '==', State.lines[loc2.line-1].dataB, State.line_cache[loc2.line-1].fragmentsB)

    print('c', loc2.line-1, State.lines[loc2.line-1].data, '==', State.lines[loc2.line-1].dataB, '==', #screen_line_starting_posB, 'starting from x', x)

--?     print('c', loc2.line-1, State.lines[loc2.line-1].data, '==', State.lines[loc2.line-1].dataB, '==', #screen_line_starting_posB, 'starting from x', x)

      print('c2')

--?       print('c2')

      print('c3')

--?       print('c3')

  -- bifold text

  elseif chord == 'C-d' then
    if State.cursor1.posB == nil then
      if State.lines[State.cursor1.line].dataB == nil then
        State.lines[State.cursor1.line].dataB = ''
      end
      State.lines[State.cursor1.line].expanded = true
      State.cursor1.pos = nil
      State.cursor1.posB = 1
      if Text.cursor_out_of_screen(State) then
        Text.snap_cursor_to_bottom_of_screen(State, State.left, State.right)
      end
    end
  -- zoom

  -- undo