forth: Forth-ify "SWAP"

forth/forth.asm

@@ -928,22 +928,10 @@ DROP:
 	pop	hl
 	jp	next
 
-; ( a b -- b a )
-	.db "SWAP"
-	.dw $-DROP
-	.db 4
-SWAP:
-	.dw nativeWord
-	pop	hl
-	call	chkPS
-	ex	(sp), hl
-	push	hl
-	jp	next
-
-.fill 149
+.fill 167
 
 	.db	"_bend"
-	.dw	$-SWAP
+	.dw	$-DROP
 	.db	5
 ; Offset: 06ee
 .out $

forth/icore.fs

@@ -122,7 +122,7 @@
     ( Adjust HERE -1 because SCPY copies the null )
     HERE @ 1 _c -   ( h h' )
     _c DUP HERE !   ( h h' )
-    SWAP _c -       ( sz )
+    _c SWAP _c -       ( sz )
     ( write prev value )
     HERE @ CURRENT @ _c - ,
     ( write size )

forth/z80c.fs

@@ -39,6 +39,15 @@ CODE DUP
     HL PUSHqq,      ( A )
 ;CODE
 
+( a b -- b a )
+CODE SWAP
+    HL POPqq,       ( B )
+    DE POPqq,       ( A )
+    chkPS,
+    HL PUSHqq,      ( B )
+    DE PUSHqq,      ( A )
+;CODE
+
 ( a b -- a b a )
 CODE OVER
     HL POPqq,       ( B )