diff --git a/readme.md b/readme.md
index c28ff00..09a4995 100644
--- a/readme.md
+++ b/readme.md
@@ -169,13 +169,18 @@ Put differently: it starts executing instructions at the address contained in `$
 
 ## Cardiograph memory map
 
-- `00-19` - display (5x5)
-- `1A   ` - pointer to display memory
-- `1B   ` - keypad: value of latest key pressed
-- `1C   ` - reserved for future use (bank switching flag)
-- `1D   ` - initial IP
-- `1D-FE` - free
-- `FF   ` - ROM (unwriteable) pointer to initial IP (not yet implemented)
+| Address  | Used for...                                   |
+|----------|-----------------------------------------------|
+| 00 to 19 | display (5x5)                                 |
+| 1A       | pointer to display memory                     |
+| 1B       | keypad: value of latest key pressed           |
+| 1C       | reserved for future use (bank switching flag) |
+| 1D       | initial IP                                    |
+| 1D to FE | free                                          |
+| FF       | * ROM (unwriteable) pointer to initial IP     |
+
+\* Not implemented yet
+
 
 ## Cardiograph peripherals