Russ,

Is this your old school again?
Amazing!

As the "quiz" series are supposed to be educational, I thought about something to point out the existence of parity flag. I could not come up with nothing better (not using EXPLICITLY the parity, such as UART transmittion with parity).

But those 2 of yours are simply... well... OK it shows a couple of interesting principles, too.

The first one is relatively straighforward, too; but you've built in a catch or two, didn't you... Let me make a variation of that one (the same speed and spares a couple of bytes):

Quiz5a: mov     b,a
        anl     a,#85
        xch     a,b
        rrc     a
        anl     a,#85
        add     a,b
        mov     b,a
        anl     a,#51
        xch     a,b
        rr      a
        rrc     a
        anl     a,#51
        add     a,b
        mov     b,#16
        div     ab
        add     a,b
        ret

The other one I admit gave me some hard time to understand... But it's definitively nice!

JW