diff --git a/TODO.md b/TODO.md
index 745816a..e30969a 100644
--- a/TODO.md
+++ b/TODO.md
@@ -4,14 +4,19 @@
 - change more methods to be direct but with buffered indirects
 - complete the GPU implementation (screen buffers and missing methods)
 - complete the screen implementation (bunch of missing methods)
+- in-memory version of `filesystem` and `drive`
+- `hologram` component
 - `computer` component
 - `modem` component
 - `tunnel` component
 - `data` component (with error correction codes)
 - `redstone` component
-- `hologram` component
 - `internet` component
-- use dynamic arrays for signals
+- `computer.getDeviceInfo()`, and subsequently, component device information
+- `computer.beep(frequency?: number, duration?: number, volume?: number)`, frequency between 20 and 2000 Hz, duration up to 5 seconds, volume from 0 to 1.
+Should use the *busy* machine state to let the sandbox suspend it until it is done playing
+- ensure the recursive locks are used correctly to prevent race conditions
+- use dynamic arrays for signals (and maybe components)
 
 # Bugfixes
 
diff --git a/src/sandbox.lua b/src/sandbox.lua
index ceed81e..941d66d 100644
--- a/src/sandbox.lua
+++ b/src/sandbox.lua
@@ -452,6 +452,7 @@ local co = coroutine.create(f)
 while true do
     timeout = nextDeadline()
     bubbleYield = false
+    collectgarbage()
 
     local ok, err = coroutine.resume(co)