diff --git a/math32.tal b/math32.tal
index e05d65b..6682720 100644
--- a/math32.tal
+++ b/math32.tal
@@ -180,19 +180,12 @@
 
 ( shift left by 8-15 bits )
 @left-shift1 ( x** n^ -> x<<n )
-    #0000 ;sh/z0 STA2 #00 ;sh/z2 STA
-    #08 SUB #40 SFT STH ( n<<4 -> r )
-    SWP SWP2 SWP POP ( x3 x2 x1 )
+    #08 SUB #40 SFT STH ( stash [n-8]<<4 )
 
-    STHkr SFT ;sh/z0 STA ( x3 x2 )
-
-    #00 SWP STHkr SFT2 ( x3 00x2<<r )
-    ;sh/z0 LDA2 ORA2 ;sh/z0 STA2 ( x3 )
-
-    #00 SWP STHr SFT2 ( 00x3<<r )
-    ;sh/z1 LDA2 ORA2 ;sh/z1 STA2 ( )
-
-    ;sh/z0 LDA2 ;sh/z2 LDA #00
+    #00 SWP STHkr SFT2                     ;sh/z1 STA2 ( store z1,z2 )
+    #00 SWP STHkr SFT2 #00 ;sh/z1 LDA ORA2 ;sh/z0 STA2 ( store z0,z1 )
+            STHr  SFT      ;sh/z0 LDA ORA              ( calculate z0 )
+    ;sh/z1 LDA2 #00
     RTN
 
 ( shift left by 16-23 bits )