diff --git a/notes/todo.md b/notes/todo.md
index 76eeb54..7c83be8 100644
--- a/notes/todo.md
+++ b/notes/todo.md
@@ -17,7 +17,7 @@
 
 ## Design
 
-- [ ] Add keypad to memory map
+- [ ] Add keypad to memory map (see [dev note](2023-08-10--dev-notes.md))
 - [ ] [Replace CHP/CFC with FHP/FTG](2023-08-07--dev-notes.md)
 - [ ] Add a flag for bank-switching to the ~zero-page