diff --git a/maze.tal b/maze.tal
index b3af832..ad84299 100644
--- a/maze.tal
+++ b/maze.tal
@@ -14,17 +14,20 @@
 %EMIT { #18 DEO }
 %SPACE { #20 EMIT }
 %NEWLINE { #0a EMIT }
-%ITERATIONS { #0100 }
 %MOD { DIVk MUL SUB }
 %MOD2 { DIV2k MUL2 SUB2 }
 %DEC { #01 SUB }
 %DEC2 { #0001 SUB2 }
 %NEGATE2 { #ffff MUL2 }
 
+( TODO: once the dimensions are finalized inline constants )
+
 %ROWS { #0027 } ( rows of cells )
 %COLS { #003f } ( columns of cells )
 %MAZEROWS { ROWS #0003 SUB2 #0002 DIV2 }
 %MAZECOLS { COLS #0003 SUB2 #0002 DIV2 }
+( %MAZEROWS { ROWS INC2 #0002 DIV2 }
+%MAZECOLS { COLS INC2 #0002 DIV2 } )
 %NORTH { COLS NEGATE2 }
 %EAST { #0001 }
 %SOUTH { COLS }
@@ -38,6 +41,10 @@
 %UNSEEN { LOAD #02 AND #00 EQU } ( cell* -> bool^ )
 %PATH { ADD2 #0002 DIV2 } ( cell1* cell2* -> cell3* )
 
+%DIGIT { #00 SWP ;digits ADD2 LDA EMIT }
+%EMIT-BYTE { DUP #04 SFT DIGIT #0f AND DIGIT }
+%EMIT-SHORT { SWP EMIT-BYTE EMIT-BYTE }
+
 ( devices )
 
 |00 @System     [ &vector $2 &pad      $6 &r      $2 &g     $2 &b      $2 ]
@@ -83,7 +90,6 @@
     ( intialize rng )
     ;init-rng JSR2
 
-(    #03 .tint STZ )
     #03 .tint STZ
     #00 .regenerate STZ
 
@@ -150,10 +156,6 @@ BRK
     &done
 BRK
 
-%DIGIT { #00 SWP ;digits ADD2 LDA EMIT }
-%EMIT-BYTE { DUP #04 SFT DIGIT #0f AND DIGIT }
-%EMIT-SHORT { SWP EMIT-BYTE EMIT-BYTE }
-
 @try-move ( drow dcol -> )
     .charx LDZ2 ADD2 SWP2 ( col+dcol row+drow )
     .chary LDZ2 ADD2 SWP2 ( row+drow dcol )
@@ -282,6 +284,15 @@ RTN
     POP2 POP2
 RTN
 
+( a move is illegal if it changes both  x and y. )
+( that occurs when the player wraps around the border. )
+@illegal-move ( cell* -> bool^ )
+    DUP2
+    COLS MOD2 ;focus LDA2 COLS MOD2 NEQ2 STH
+    ROWS DIV2 ;focus LDA2 ROWS DIV2 NEQ2 STHr
+    AND
+RTN
+
 @create-maze ( -> )
     ( create starting pt, must have even coords )
     ;random-short JSR2 MAZEROWS MOD2 INC2 #0002 MUL2 ( row* )
@@ -297,8 +308,10 @@ RTN
     DUP .directions ADD LDZ ( i^ d^ )
     DUP #02 MUL .cell-offsets ADD LDZ2 ( i^ d^ off* )
     DUP2 ;focus LDA2 ADD2 ADD2 ( i^ d^ cell2* )
+    DUP2 ;illegal-move JSR2 ,&notfound JCN
     DUP2 UNSEEN ( i^ d^ cell2* unseen^ )
     ,&found JCN ( i^ d^ cell2* )
+    &notfound
     POP2 POP INC ( j=i+1 )
     DUP #04 LTH ( j^ j<4 )
     ,&search JCN ( j^ )