diff --git a/blk.fs b/blk.fs
index 8040a8b..9b94928 100644
--- a/blk.fs
+++ b/blk.fs
@@ -2214,24 +2214,24 @@ See doc/grid.txt.
 Load range: B402-B403
 ( ----- 402 )
 : XYPOS [ GRID_MEM LITN ] ; : XYMODE [ GRID_MEM LITN ] 2+ ;
-: _cl* COLS LINES * ;
-: AT-XY ( x y -- ) COLS * + _cl* MOD XYPOS ! ;
+'? CURSOR! NIP NOT [IF] : CURSOR! DROP ; [THEN]
+: XYPOS! COLS LINES * MOD DUP CURSOR! XYPOS ! ;
+: AT-XY ( x y -- ) COLS * + XYPOS! ;
 '? NEWLN NIP NOT [IF]
 : NEWLN ( ln -- ) COLS * DUP COLS + SWAP DO 0 I CELL! LOOP ;
 [THEN]
 : _lf XYMODE C@ IF EXIT THEN
     XYPOS @ COLS / 1+ LINES MOD DUP NEWLN
-    COLS * XYPOS ! ;
-: _bs 0 ( blank ) XYPOS @ TUCK CELL! ( pos ) 1-
-    _cl* MOD XYPOS ! ;
+    COLS * XYPOS! ;
+: _bs 0 ( blank ) XYPOS @ TUCK CELL! ( pos ) 1- XYPOS! ;
 ( ----- 403 )
 : (emit)
     DUP 0x08 = IF DROP _bs EXIT THEN
     DUP 0x0d = IF DROP _lf EXIT THEN
     0x20 - DUP 0< IF DROP EXIT THEN
     XYPOS @ CELL!
-    XYPOS @ 1+ DUP COLS MOD IF XYPOS ! ELSE _lf THEN ;
-: GRID$ 0 XYPOS ! 0 XYMODE C! ;
+    XYPOS @ 1+ DUP COLS MOD IF XYPOS! ELSE _lf THEN ;
+: GRID$ 0 XYPOS! 0 XYMODE C! ;
 ( ----- 410 )
 PS/2 keyboard subsystem
 
diff --git a/cvm/forth.fs b/cvm/forth.fs
index a6899bf..ad37562 100644
--- a/cvm/forth.fs
+++ b/cvm/forth.fs
@@ -1,6 +1,6 @@
 : COLS 80 ; : LINES 32 ;
-: CELL! ( g pos -- )
-    COLS /MOD 6 PC! ( y ) 5 PC! ( x ) 0x20 + 0 PC! ;
+: CURSOR! ( pos -- ) COLS /MOD 6 PC! ( y ) 5 PC! ( x ) ;
+: CELL! ( g pos -- ) CURSOR! 0x20 + 0 PC! ;
 : NEWLN ( ln -- ) DROP 0xa 0 PC! ;
 
 SYSVARS 0x70 + CONSTANT GRID_MEM
diff --git a/doc/protocol.txt b/doc/protocol.txt
index fc833be..e92d6f4 100644
--- a/doc/protocol.txt
+++ b/doc/protocol.txt
@@ -48,6 +48,7 @@ CELL!     g pos -- Set glyph at pos
 
 Optional:
 NEWLN     ln --    "Enter" line ln
+CURSOR!   pos --   Set cursor's position
 
 "pos" is a simple number (y * cols) + x. For example, if we
 have 40 columns per line, the position (x, y) (12, 10) is 412.
@@ -69,3 +70,7 @@ time.
 If it's not defined, the grid system uses multiple CELL!
 calls to clear it. On some devices, this is highly inefficient.
 Drivers for those devices should define NEWLINE.
+
+CURSOR! is called whenever we change the cursor's position. If
+not implemented, it will be a noop. It is never called with an
+out of range "pos" (greater than COLS*LINES).