diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,13 @@
+concurrent-output (1.8.0) unstable; urgency=medium
+
+  * Added displayUpdateNotifier, which can be used to wait for
+    changes to console regions to be displayed.
+    (stmdemo has an example of using that to temporarily shut down the
+    region based display to run a bash prompt, and restore the region
+    display later.)
+
+ -- Joey Hess <id@joeyh.name>  Fri, 12 May 2017 16:27:41 -0400
+
 concurrent-output (1.7.9) unstable; urgency=medium
 
   * Allow lazy text to be used as an Outputable value, and as
diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright © 2015 Joey Hess <id@joeyh.name>
+Copyright © 2015-2017 Joey Hess <id@joeyh.name>
 Copyright © 2009 Joachim Breitner
 
 Redistribution and use in source and binary forms, with or without
diff --git a/System/Console/Regions.hs b/System/Console/Regions.hs
--- a/System/Console/Regions.hs
+++ b/System/Console/Regions.hs
@@ -108,6 +108,8 @@
 	consoleWidth,
 	consoleHeight,
 	regionList,
+	displayUpdateNotifier,
+	DisplayChange(..),
 ) where
 
 import Data.Monoid
@@ -207,11 +209,17 @@
 consoleHeight :: STM Int
 consoleHeight = Console.height <$> readTVar consoleSize
 
--- | The RegionList TMVar is left empty when `displayConsoleRegions`
--- is not running.
+-- | Check if `displayConsoleRegions` is running.
 regionDisplayEnabled :: IO Bool
 regionDisplayEnabled = atomically $ not <$> isEmptyTMVar regionList
 
+-- | This is a broadcast TChan, which gets a DisplayChange written to it
+-- after the display has been updated. It can be used to wait for something
+-- to be displayed.
+{-# NOINLINE displayUpdateNotifier #-}
+displayUpdateNotifier :: TChan DisplayChange
+displayUpdateNotifier = unsafePerformIO $ newBroadcastTChanIO
+
 -- | Many actions in this module can be run in either the IO monad
 -- or the STM monad. Using STM allows making several changes to the
 -- displayed regions atomically, with the display updated a single time.
@@ -431,17 +439,19 @@
 
 trackConsoleWidth :: IO ()
 trackConsoleWidth = do
-	let getwidth = maybe noop (atomically . writeTVar consoleSize)
+	let getsz = maybe noop (atomically . writeTVar consoleSize)
 		=<< Console.size
-	getwidth
-	installResizeHandler (Just getwidth)
+	getsz
+	installResizeHandler (Just getsz)
 
 data DisplayChange
-	= BufferChange (StdHandle, OutputBuffer)
+	= BufferChange BufferSnapshot 
 	| RegionChange RegionSnapshot
+	| RegionListChange RegionSnapshot
 	| TerminalResize Width
-	| EndSignal ()
+	| Shutdown
 
+type BufferSnapshot = (StdHandle, OutputBuffer)
 type RegionSnapshot = ([ConsoleRegion], [R], [[Text]])
 
 displayThread :: Bool -> TSem -> IO ()
@@ -456,22 +466,24 @@
 		let waitanychange =
 			(RegionChange <$> regionWaiter origsnapshot origwidth)
 				`orElse`
-			(RegionChange <$> regionListWaiter origsnapshot)
+			(RegionListChange <$> regionListWaiter origsnapshot)
 				`orElse`
 			(BufferChange <$> outputBufferWaiterSTM waitCompleteLines)
 				`orElse`
 			(TerminalResize <$> waitwidthchange)
 				`orElse`
-			(EndSignal <$> waitTSem endsignal)
+			(waitTSem endsignal >> pure Shutdown)
 		(change, height) <- atomically $ (,)
 			<$> waitanychange
 			<*> consoleHeight
 		let onscreen = take (height - 1) . concat
-		case change of
-			RegionChange snapshot@(_, _, newlines) -> do
-				when isterm $ do
-					changedLines (onscreen origlines) (onscreen newlines)
-				go snapshot origwidth
+		let update snapshot@(_, _, newlines) = do
+			when isterm $ do
+				changedLines (onscreen origlines) (onscreen newlines)
+			return $ go snapshot origwidth
+		next <- case change of
+			RegionChange snapshot -> update snapshot
+			RegionListChange snapshot -> update snapshot
 			BufferChange (h, buf) -> do
 				-- Note that even when every available line
 				-- is dedicated to visible regions, the
@@ -481,13 +493,15 @@
 				let origlines' = onscreen origlines
 				inAreaAbove isterm (length origlines') origlines' $
 					emitOutputBuffer h buf
-				go origsnapshot origwidth
+				return $ go origsnapshot origwidth
 			TerminalResize newwidth -> do
 				newlines <- atomically (mapM (resizeRegion newwidth) orighandles)
 				when isterm $ do
 					resizeRecovery (onscreen newlines)
-				go (orighandles, origregions, newlines) newwidth
-			EndSignal () -> return ()
+				return $ go (orighandles, origregions, newlines) newwidth
+			Shutdown -> return $ return ()
+		atomically $ writeTChan displayUpdateNotifier change
+		next
 
 readRegions :: [ConsoleRegion] -> STM [R]
 readRegions = mapM (\(ConsoleRegion h) -> readTVar h)
diff --git a/concurrent-output.cabal b/concurrent-output.cabal
--- a/concurrent-output.cabal
+++ b/concurrent-output.cabal
@@ -1,11 +1,11 @@
 Name: concurrent-output
-Version: 1.7.9
+Version: 1.8.0
 Cabal-Version: >= 1.8
 License: BSD2
 Maintainer: Joey Hess <id@joeyh.name>
 Author: Joey Hess, Joachim Breitner
 Stability: Stable
-Copyright: 2015 Joey Hess, 2009 Joachim Breitner
+Copyright: 2015-2017 Joey Hess, 2009 Joachim Breitner
 License-File: LICENSE
 Build-Type: Simple
 Category: User Interfaces
diff --git a/stmdemo.hs b/stmdemo.hs
--- a/stmdemo.hs
+++ b/stmdemo.hs
@@ -7,15 +7,25 @@
 import Data.Time.Clock
 import Control.Monad
 import Data.Monoid
+import System.Process
 
 main :: IO ()
 main = void $ displayConsoleRegions $ do
+	void titleRegion
 	ir <- infoRegion
 	cr <- clockRegion
 	rr <- rulerRegion
 	growingDots
+	runBash
+	growingDots
 	mapM_ closeConsoleRegion [ir, cr]
 
+titleRegion :: IO ConsoleRegion
+titleRegion = do
+	r <- openConsoleRegion Linear
+	setConsoleRegion r "STM demo!"
+	return r
+
 infoRegion :: IO ConsoleRegion
 infoRegion = do
 	r <- openConsoleRegion Linear
@@ -48,24 +58,43 @@
 		rightAlign r
 		return r
 
+rulerRegion :: IO ConsoleRegion
+rulerRegion = do
+	r <- openConsoleRegion Linear
+	setConsoleRegion r $ do
+		width <- consoleWidth
+		return $ T.pack $ take width nums
+	return r
+  where
+	nums = cycle $ concatMap show [0..9]
+
 rightAlign :: ConsoleRegion -> STM ()
 rightAlign r = tuneDisplay r $ \t -> do
         w <- consoleWidth
         return (T.replicate (w - T.length t) (T.singleton ' ') <> t)
 
+growingDots :: IO ()
 growingDots = withConsoleRegion Linear $ \r -> do
 	atomically $ rightAlign r
 	width <- atomically consoleWidth
-	replicateM width $ do
+	void $ replicateM width $ do
 		appendConsoleRegion r "." 
 		threadDelay (100000)
 
-rulerRegion :: IO ConsoleRegion
-rulerRegion = do
-	r <- openConsoleRegion Linear
-	setConsoleRegion r $ do
-		width <- consoleWidth
-		return $ T.pack $ take width nums
-	return r
-  where
-	nums = cycle $ concatMap show [0..9]
+runBash :: IO ()
+runBash = do
+	c <- atomically $ dupTChan displayUpdateNotifier
+	-- Temporarily clear whatever console regions are open.
+	rs <- atomically $ swapTMVar regionList []
+	atomically $ waitDisplayUpdate c
+	putStrLn "We interrupt this demo to run a shell prompt. exit to continue!"
+	callCommand "bash"
+	-- Restore the console regions.
+	void $ atomically $ swapTMVar regionList rs
+
+waitDisplayUpdate :: TChan DisplayChange -> STM ()
+waitDisplayUpdate c = do
+	v <- readTChan c
+	case v of
+		RegionListChange ([],_,_) -> return ()
+		_ -> waitDisplayUpdate c