Wagner,

I see your point.  It would be slightly more than a dollar, but hey,
cheap at that.

Greg

Wagner Lipnharski wrote:
>
> Greg,
> In real I am spreading the idea. Suppose there are no persons, but
> machines, circuits voting, then speed is totaly dependent.  I still
> believing a $10 circuit is cheap.  A single key and one lamp would cost
> much more than all the electronic gates necessary to make it by the
> right way.  If a key spring is stronger then other and it would delay
> the contestant answer (even that the rule is "who makes first the switch
> click", so key spring doesn't count), initially you don't have a way to
> know that, and it makes part of the game, the same way if a contestant
> is faster to know the answer but lazy to press the button.  Still
> winning who makes first the click at the switch. But you already know
> that a priority encoder circuit has a tendency, so it is changing the
> situation about who made the first click.
>
> Now, suppose you have 10 PIC units collecting data and you want to know
> which one ends up first the calculation or data gattering, would you
> still using the 148? for sure not.  Then, by the same price you can have
> a "correct" way to do that.
>
> Lets see;  each 74HCT00 can be used to build the necessary flip latches
> for two contestants, so you would need 5 units, each one cost around
> $0.20, you will spend $1.00 to have the right timming circuit, with less
> than 10ns of possible error.  Increasing $1.00 in your Quiz Master to
> make it "correct" is too expensive?  I don't think so.  Then use a 10 to
> 4 encoder and a shift register to send the 4 bits to the pic in just few
> wires....
>
> I am not trying to tell you what you should do, just telling you that
> there are better ways to do it by the same cost.
>
> :)
> Wagner
>
> Greg Brault wrote:
> >
> > Wagner,
> > I disagree.
> > Like someone had posted earlier today (sorry, i don't remember!), the
> > composition of the switches, spring constants, etc, add more variables
> > to the scenerio.  So (as quoted earlier today), the person who may know
> > the answer first, and pushes the button in the SAME INSTANT (within
> > microseconds) as another player, and even having top priority, still may
> > not get it.  Plus, I was in quizbowl for my entire high school career.
> > Their systems cost A LOT of money, and i wanted to build one for cheap.
> > very rarely did i see two lights on at the same time... indicating two
> > people were within that margin of time to do that (this can't even
> > happen with the encoder design ... just showing how often that scenerio
> > would happen)
> > Greg
> >
> > Wagner Lipnharski wrote:
> > >
> > > Greg Brault wrote:
> > > >
> > > > priority chip # is 74148
> > > >
> > >
> > > Tell me which button would be the higher order, I will be there.
> > > If everybody presses the button at the same time, I will always win.
> > > According to my point of view, this is not the best chip for the job.
> > > Simple J-K flip-flops would work better, then feed them to the 148.
> > > Wagner