core: add word "MOVE"

dictionary.txt

@@ -98,6 +98,8 @@ C!          c a --          Store byte c in address a
 CURRENT     -- a            Set a to wordref of last added entry.
 HERE        -- a            Push HERE's address
 H@          -- a            HERE @
+MOVE        a1 a2 u --      Copy u bytes from a1 to a2, starting with a1, going
+                            up.
 
 *** Arithmetic / Bits ***
 

forth/core.fs

@@ -118,3 +118,12 @@
 ( Set up initial SYSVNXT value, which is 2 bytes after its
   own address )
 46 RAM+ DUP 2 + SWAP !
+
+( a1 a2 u -- )
+: MOVE
+    ( u ) 0 DO
+        SWAP DUP I + @    ( a2 a1 x )
+        ROT SWAP OVER I + ( a1 a2 x a2 )
+        !                 ( a1 a2 )
+    LOOP
+;