CODE + AX POPx, BX POPx, AX BX ADDxx, AX PUSHx, ;CODE
CODE - BX POPx, AX POPx, AX BX SUBxx, AX PUSHx, ;CODE
CODE *
    AX POPx, BX POPx,
    DX PUSHx, ( protect from MUL ) BX MULx, DX POPx,
    AX PUSHx,
;CODE
CODE /MOD
    BX POPx, AX POPx, DX PUSHx, ( protect )
    DX DX XORxx, BX DIVx,
    BX DX MOVxx, DX POPx, ( unprotect )
    BX PUSHx, ( modulo ) AX PUSHx, ( division )
;CODE