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,
    BL DIVr, ( TODO: use DIVx, risk of 8086 error )
    BH BH XORrr, BL AH MOVrr, BX PUSHx, ( modulo )
    BL AL MOVrr, BX PUSHx, ( division )
;CODE