diff --git a/0019-B b/0019-B
index 43c72b6..56dc5cf 100644
--- a/0019-B
+++ b/0019-B
@@ -1,4 +1,5 @@
 B = function(skip_updating_screen_top_for)
+print('B', skip_updating_screen_top_for)
 	-- recompute various aspects based on the current viewport settings
 	for _,obj in ipairs(Surface) do
 		if obj.type == 'line' then
@@ -22,4 +23,5 @@ B = function(skip_updating_screen_top_for)
 			end
 		end
 	end
+	print('end B', skip_updating_screen_top_for)
 end
diff --git a/0021-compute_layout b/0021-compute_layout
index 86d1d3c..3324470 100644
--- a/0021-compute_layout
+++ b/0021-compute_layout
@@ -1,4 +1,7 @@
 compute_layout = function(node, x,y, nodes_to_render, skip_updating_screen_top_for)
+if node.editor then
+print('compute_layout', node, node.type, node.editor.screen_top1.line, skip_updating_screen_top_for)
+end
 	-- append to nodes_to_render flattened instructions to render a hierarchy of nodes
 	-- return x,y rendered until (surface coordinates)
 	if node.type == 'text' then
@@ -59,7 +62,7 @@ compute_layout = function(node, x,y, nodes_to_render, skip_updating_screen_top_f
 			if not child.width then
 				child.width = node.width  -- HACK: should we set child.w or child.width? Neither is quite satisfactory.
 			end
-			subx,suby = compute_layout(child, x,suby, nodes_to_render)
+			subx,suby = compute_layout(child, x,suby, nodes_to_render, skip_updating_screen_top_for)
 			if w < child.w then
 				w = child.w
 			end
@@ -87,7 +90,7 @@ compute_layout = function(node, x,y, nodes_to_render, skip_updating_screen_top_f
 				subx = subx+child.margin
 				w = w+child.margin
 			end
-			subx,suby = compute_layout(child, subx,y, nodes_to_render)
+			subx,suby = compute_layout(child, subx,y, nodes_to_render, skip_updating_screen_top_for)
 			w = w + child.w
 			if h < child.h then
 				h = child.h
@@ -100,5 +103,6 @@ compute_layout = function(node, x,y, nodes_to_render, skip_updating_screen_top_f
 			node_to_render.h = h
 		end
 	end
+	print('end compute_layout', skip_updating_screen_top_for, node)
 	return x+node.w,y+node.h
 end
diff --git a/0023-on.keychord_press b/0023-on.keychord_press
index b1f8e2d..a07b87d 100644
--- a/0023-on.keychord_press
+++ b/0023-on.keychord_press
@@ -22,8 +22,9 @@ on.keychord_press = function(chord, key)
 		if not eq(Cursor_node.editor.screen_top1, old_top) then
 			print('==', old_top.line, old_top.pos, '=>', Cursor_node.editor.screen_top1.line, Cursor_node.editor.screen_top1.pos)
 			Viewport.y = Cursor_node.y + y_of_schema1(Cursor_node.editor, Cursor_node.editor.screen_top1)
-			print('=>', Viewport.y)
+			print('->', Viewport.y, Cursor_node.editor.top, Cursor_node.editor.screen_top1.line)
 			A(--[[skip updating screen_top for]] Cursor_node)
+			print('=>', Viewport.y, Cursor_node.editor.top, Cursor_node.editor.screen_top1.line)
 			return
 		end
 		A()
diff --git a/0026-on.draw b/0026-on.draw
index f160288..64e4247 100644
--- a/0026-on.draw
+++ b/0026-on.draw
@@ -32,8 +32,9 @@ on.draw = function()
 			if obj.w == nil then
 				love.graphics.draw(obj.text, vx(obj.x), vy(obj.y))
 			else
+--? 				print('edit.draw', obj.y, obj.editor.top, obj.editor.screen_top1.line)
 				edit.draw(obj.editor, obj.fg or {r=0,g=0,b=0}, not obj.show_cursor)
 			end
 		end
 	end
-end
\ No newline at end of file
+end
diff --git a/0028-A b/0028-A
index 2d44c6b..b6d8a1e 100644
--- a/0028-A
+++ b/0028-A
@@ -1,8 +1,11 @@
 A = function(skip_updating_screen_top_for)
+	print('A', skip_updating_screen_top_for)
 	love.graphics.setFont(love.graphics.newFont(scale(20)))  -- editor objects implicitly depend on current font
 	Surface = {}
+	print('calling compute_layout', Page, Page.x,Page.y, Surface, skip_updating_screen_top_for)
 	compute_layout(Page, Page.x,Page.y, Surface, skip_updating_screen_top_for)
 	-- continue the pipeline
 	B(skip_updating_screen_top_for)
 	-- TODO: ugly that we're manipulating editor objects twice
+	print('end A', skip_updating_screen_top_for)
 end
diff --git a/0030-update_editor_box b/0030-update_editor_box
index 0f807dc..31feb97 100644
--- a/0030-update_editor_box
+++ b/0030-update_editor_box
@@ -1,7 +1,9 @@
 update_editor_box = function(node, skip_updating_screen_top_for)
 	if node.editor == nil then return end
+	print('update box', node, node.editor.screen_top1.line, skip_updating_screen_top_for)
 	edit.update_font_settings(node.editor, scale(20))
 	if node ~= skip_updating_screen_top_for then
+		print('update box: refreshing screen top', node.editor.screen_top1.line)
 		if node.y > Viewport.y then
 			node.editor.screen_top1.line = 1
 			node.editor.screen_top1.pos = 1
@@ -9,9 +11,12 @@ update_editor_box = function(node, skip_updating_screen_top_for)
 		else
 			node.editor.screen_top1, node.editor.top = schema1_of_y(node.editor, scale(Viewport.y-node.y))
 		end
+	else
+		print('update box: NOT refreshing screen top', node.editor.screen_top1.line)
 	end
 	node.editor.left = math.floor(vx(node.x))
 	node.editor.right = math.ceil(vx(node.x+node.w))
 	node.editor.width = node.editor.right - node.editor.left
 	Text.redraw_all(node.editor)
+	print('end update box', node, skip_updating_screen_top_for)
 end
diff --git a/text.lua b/text.lua
index a2575ca..31ed920 100644
--- a/text.lua
+++ b/text.lua
@@ -204,11 +204,11 @@ function Text.keychord_press(State, chord, readonly)
       end
     elseif State.cursor1.line > 1 then
       before = snapshot(State, State.cursor1.line-1, State.cursor1.line)
-      -- join lines
-      State.cursor1.pos = utf8.len(State.lines[State.cursor1.line-1].data)+1
-      State.lines[State.cursor1.line-1].data = State.lines[State.cursor1.line-1].data..State.lines[State.cursor1.line].data
-      table.remove(State.lines, State.cursor1.line)
-      table.remove(State.line_cache, State.cursor1.line)
+        -- join lines
+        State.cursor1.pos = utf8.len(State.lines[State.cursor1.line-1].data)+1
+        State.lines[State.cursor1.line-1].data = State.lines[State.cursor1.line-1].data..State.lines[State.cursor1.line].data
+        table.remove(State.lines, State.cursor1.line)
+        table.remove(State.line_cache, State.cursor1.line)
       State.cursor1.line = State.cursor1.line-1
     end
     if State.screen_top1.line > #State.lines then
@@ -250,8 +250,8 @@ function Text.keychord_press(State, chord, readonly)
         -- no change to State.cursor1.pos
       end
     elseif State.cursor1.line < #State.lines then
-      -- join lines
-      State.lines[State.cursor1.line].data = State.lines[State.cursor1.line].data..State.lines[State.cursor1.line+1].data
+        -- join lines
+        State.lines[State.cursor1.line].data = State.lines[State.cursor1.line].data..State.lines[State.cursor1.line+1].data
       table.remove(State.lines, State.cursor1.line+1)
       table.remove(State.line_cache, State.cursor1.line+1)
     end
@@ -363,7 +363,7 @@ function Text.pageup(State)
   while y >= State.top do
 --?     print(y, top2.line, top2.screen_line, top2.screen_pos)
     if State.screen_top1.line == 1 and State.screen_top1.pos == 1 then break end
-    y = y - State.line_height
+      y = y - State.line_height
     top2 = Text.previous_screen_line(State, top2)
   end
   State.screen_top1 = Text.to1(State, top2)
@@ -435,42 +435,42 @@ function Text.up(State)
 end
 
 function Text.down(State)
---?   print('down', State.cursor1.line, State.cursor1.pos, State.screen_top1.line, State.screen_top1.pos, State.screen_bottom1.line, State.screen_bottom1.pos)
+  print('down', State.cursor1.line, State.cursor1.pos, State.screen_top1.line, State.screen_top1.pos, State.screen_bottom1.line, State.screen_bottom1.pos)
   assert(State.cursor1.pos)
   if Text.cursor_at_final_screen_line(State) then
     -- line is done, skip to next text line
---?     print('cursor at final screen line of its line')
+    print('cursor at final screen line of its line')
     if State.cursor1.line < #State.lines then
       local new_cursor_line = State.cursor1.line+1
       State.cursor1.line = new_cursor_line
       State.cursor1.pos = Text.nearest_cursor_pos(State.lines[State.cursor1.line].data, State.cursor_x, State.left)
---?       print(State.cursor1.pos)
+      print(State.cursor1.pos)
     end
     if State.cursor1.line > State.screen_bottom1.line then
---?       print('screen top before:', State.screen_top1.line, State.screen_top1.pos)
---?       print('scroll up preserving cursor')
+      print('screen top before:', State.screen_top1.line, State.screen_top1.pos)
+      print('scroll up preserving cursor')
       Text.snap_cursor_to_bottom_of_screen(State)
---?       print('screen top after:', State.screen_top1.line, State.screen_top1.pos)
+      print('screen top after:', State.screen_top1.line, State.screen_top1.pos)
     end
   else
     -- move down one screen line in current line
     local scroll_down = Text.le1(State.screen_bottom1, State.cursor1)
---?     print('cursor is NOT at final screen line of its line')
+    print('cursor is NOT at final screen line of its line')
     local screen_line_starting_pos, screen_line_index = Text.pos_at_start_of_screen_line(State, State.cursor1)
     Text.populate_screen_line_starting_pos(State, State.cursor1.line)
     local new_screen_line_starting_pos = State.line_cache[State.cursor1.line].screen_line_starting_pos[screen_line_index+1]
---?     print('switching pos of screen line at cursor from '..tostring(screen_line_starting_pos)..' to '..tostring(new_screen_line_starting_pos))
+    print('switching pos of screen line at cursor from '..tostring(screen_line_starting_pos)..' to '..tostring(new_screen_line_starting_pos))
     local new_screen_line_starting_byte_offset = Text.offset(State.lines[State.cursor1.line].data, new_screen_line_starting_pos)
     local s = string.sub(State.lines[State.cursor1.line].data, new_screen_line_starting_byte_offset)
     State.cursor1.pos = new_screen_line_starting_pos + Text.nearest_cursor_pos(s, State.cursor_x, State.left) - 1
---?     print('cursor pos is now', State.cursor1.line, State.cursor1.pos)
+    print('cursor pos is now', State.cursor1.line, State.cursor1.pos)
     if scroll_down then
---?       print('scroll up preserving cursor')
+      print('scroll up preserving cursor')
       Text.snap_cursor_to_bottom_of_screen(State)
---?       print('screen top after:', State.screen_top1.line, State.screen_top1.pos)
+      print('screen top after:', State.screen_top1.line, State.screen_top1.pos)
     end
   end
---?   print('=>', State.cursor1.line, State.cursor1.pos, State.screen_top1.line, State.screen_top1.pos, State.screen_bottom1.line, State.screen_bottom1.pos)
+  print('=>', State.cursor1.line, State.cursor1.pos, State.screen_top1.line, State.screen_top1.pos, State.screen_bottom1.line, State.screen_bottom1.pos)
 end
 
 function Text.start_of_line(State)
@@ -632,11 +632,11 @@ function Text.snap_cursor_to_bottom_of_screen(State)
   while true do
 --?     print(y, 'top2:', top2.line, top2.screen_line, top2.screen_pos)
     if top2.line == 1 and top2.screen_line == 1 then break end
-    local h = State.line_height
-    if y - h < State.top then
-      break
-    end
-    y = y - h
+      local h = State.line_height
+      if y - h < State.top then
+        break
+      end
+      y = y - h
     top2 = Text.previous_screen_line(State, top2)
   end
 --?   print('top2 finally:', top2.line, top2.screen_line, top2.screen_pos)
@@ -906,6 +906,7 @@ end
 -- slightly expensive since it redraws the screen
 function Text.cursor_out_of_screen(State)
   edit.draw(State, --[[should be drawn over]] Cursor_color)
+  print('cursor out of screen?', State.cursor_y == nil)
   return State.cursor_y == nil
   -- this approach is cheaper and almost works, except on the final screen
   -- where file ends above bottom of screen