diff --git a/todo.md b/todo.md
index 1281de7..6fb0282 100644
--- a/todo.md
+++ b/todo.md
@@ -1,5 +1,11 @@
 things to try:
 
+* skip add on the top-byte multiply in sqr8/mul8
+  * should save a few cycles, suggestion by jamey
+
+* perform the zx += zx^s + cx in 32-bit space, before rounding
+  * should improve precision on max zoom, might cost a few cycles
+
 * patch the entire expanded-ram imul8xe on top of imul8 to avoid the 3-cycle thunk penalty :D
 
 * try 3.13 fixed point instead of 4.12 for more precision