CODE DUP AX POPx, AX PUSHx, AX PUSHx, ;CODE
CODE ?DUP AX POPx, AX AX ORxx, IFNZ, AX PUSHx, THEN, ;CODE
CODE DROP AX POPx, ;CODE
CODE SWAP AX POPx, BX POPx, AX PUSHx, BX PUSHx, ;CODE
CODE OVER ( a b -- a b a )
    DI SP MOVxx, AX [DI] 2 MOVx[]+, AX PUSHx,
;CODE
CODE 0 AX AX XORxx, AX PUSHx, ;CODE
CODE 1 AX 1 MOVxI, AX PUSHx, ;CODE
CODE I [BP] 0 PUSH[w]+, ;CODE
CODE 1+ DI SP MOVxx, [DI] INC[w], ;CODE
CODE 1- DI SP MOVxx, [DI] DEC[w], ;CODE