CODE DROP ( a -- )
HL POP, chkPS,
;CODE
CODE SWAP ( a b -- b a )
HL POP, ( B ) DE POP, ( A )
chkPS,
HL PUSH, ( B ) DE PUSH, ( A )
CODE OVER ( a b -- a b a )
DE PUSH, ( A ) HL PUSH, ( B ) DE PUSH, ( A )