Wanted: A Very Accurate Timer

--- For me, your suggestion that he use a 120Hz clock implies that you don't know what you're talking about.

Considering that the OP has specified that: "It must to be accurate to within 1/60th of a second over the course of 6 hours."

means that, since there are 3600 seconds in an hour there will be

21,600 seconds in six hours, and since he wants to split the seconds into 60 slivers each, there will be 1,296,000 slivers in six hours.

Since he states that the accuracy must be _within_ 1 sliver, that means he needs an accuracy of one part in 1,296,000. Looking at it from a different perspective, that's an accuracy of +/- 0.000038580%.

Now, what was it you were saying about that 120Hz clock?

-- John Fields Professional Circuit Designer

You certainly appear to be trolling.

Your original question was fully answered several times, as were your followups where you kept adding details that you left out.

Please read this:

How To Ask Questions The Smart Way

I am no fan of the usual flamewars and topic drift here, but in this case the fault is 100% yours. You won't get a good answer anywhere else unless you read the above website and start following the advice in it.

Followups set. If you don't know what that means, find out.

But have you read them? Apart from that you may not be able to interpret them, I know you got some useful advise. I suggested you use an 120Hz clock, so you will actually obtain the sampling resolution you want. I have not seen you respond to that, thankful nor rejective. For me that implies you should really find an electronics designer to work with.

--
Met vriendelijke groet,

   Maarten Bakker.

The suggestion was faulty. That is why that post of his is now gone.

Darren Harris Staten Island, New York.

Only to someone who doesn't know what trolling is.

Totally incorrect. Find a single post in this thread where it was answered completely.

And I added no details that I "left out". Those "follow ups" should not have happened, since they were off post. But certain people kept needling me for details.

What for?

I don't need to read any such website.

The topic drift here is not my fault. Would it take a genius to answer the question in the first post without needing more details?

Evidently so.

Again, I have whatever answers I can get here. Let it go.

Darren Harris Staten Island, New York.

I rejected most suggestions because I did understand them,and they were adequate for my needs. Only someone truly stupid would not understand that.

Of those links that were posted, I have yet to hear back from the one company I e-mailed. And the timers didn't have enough details or were totally inadequate for my purposes.(Like those Ebay links you posted).

I read all the advice here and said thanks a several times throughout the thread, and stated that I got all the info I could get here. What else do you want from me? The crap is over details that certain individuals are looking for. Those details are complicated and totally off topic.

Darren Harris Staten Island, New York.

I'm guessing that you're trying to beat some sort of gambling/gaming system that uses a pseudorandom sequence clocked at 60Hz. A few off-the-wall comments:

1. You don't have to do it consistently, just enough to put the odds in your favor. Most games are set by law to returns in the 40-48% range. Just "hitting the button" in a 1/6 second window (sounds feasible to me) where you know you've got a 7 or 8 out of 10 chance is way better. You don't wait for the 1/60th of a second where you know you win, but instead you wait for a 1/6sec window where there's a really good chance you'll win.
2. The gaming system's clock is probably nowhere near the 1ppm accuracy you're stating that you require. It would probably make more sense to try to phase-lock the "guesser" to the system. This isn't easy if there's a lot of noise and other pseudo-random uncertainties involved, but it's not impossible.

If the gaming system is locked to AC power, then there's enough 60Hz ripple in the light out of a fluorescent or incadescent to lock to that easily.

I'd be very surprised if a gaming system had a 1/60 second clock, BTW.

Tim.

Zaadvragende Ogen! ;-P

With Friendly Greets, Rich

DOOOD!!!!! =:-O

He's trying to cheat the slots?!?!??? F-ck, man, I thought he just wanted to reinvent Bazo's Breaker or something.

Speaking of screwing a casino, I'd rather deal with real feds than casino security. Like, for example, printing out a scan of a bill, then trying to use it in a casino changer - you wouldn't even make it out of the building. (although, I haven't tried to pass one to a blackjack dealer...) But the little girl at the bank teller window will happily break it to small bills for you - or actually, the easiest place to pass bogus bills is at the nudie bar - you flash your bogus twenty, and ask the babe for change. Then you leave, and go to the next nudie bar, where you rip off another bimbo $19.00.

It's almost trivial. >;->

(of course, if you're going for hundreds or thousands, then you'll have to find your own foreign investors. I hear gun-running pays pretty well, if you like that sort of people.)

Chears! Rich

I was not presenting it as a complete solution, but as a useful part of finding another strategy to solve the problem.

--
Met vriendelijke groet,

   Maarten Bakker.

Problem with looking for advise or information on usenet is that you are not the person who is in control over what others do to help you. It's the other way around. If someone has an idea, he or she will try to help you as good as possible. The more questions you are asked, the better. It means people are really trying to help. In the end you will have to evaluate all answers you get yourself. The more answers you reject, the more dissatisfied you will be with the help you are getting. I myself have not analysed your problem toroughly (as repair and design is a hobby and I have more things to do for which my time is paid), but I did try to give you some hints for other approaches that may work. That is the kind of information you will get from the usenet. With lots of luck you will find an out-of-the box solution here, but that is in no way guaranteed.

--
Met vriendelijke groet,

   Maarten Bakker.

What?!?

Was that paragraph really necessary?

The problem is the *abuse*. Being called stupid, and troll, or a bonehead by individuals who couldn't even understand the question, let alone come up with answers.

Darren Harris Staten Island, New York.

Thanks.

I agree with all that. But what I'm doing has nothing to do with a gambling system.

Darren Harris Staten Island, New York.

You seem to know quite a bit about this stuff.

Personal experience perhaps? :-)

Sigh...

OK. Here we go.

There are 3 or 4 gamers in the U.S. who have confirmed ability to play the classic game Ms.Pac-man all the way to the end(133 mazes), while consuming *all* of the bonus prizes and monsters along the way.

The problem is that our highest scores vary by as much as 100,000 points. So the scores cannot really be a determining factor as far as who the best in the world is at this game, because we have all accomplished the same thing. We cannot go further thanks to the game's end.

Our varying high scores are attributed to the "random" aspects of the game. There are 252 "random" bonus prizes in a complete game, and these prizes vary in value from 100 points(Cherry) to 5,000 points(Bananna).

register that determines which bonus prizes appear at any given time incriments 60 times a second. So in 7/60th of a second it will incriment through all 7 bonus prizes before beginning again. And the last joystick input before the dot that triggers the prize output is eaten is responsible for which prize appears. Now if a player could determine the exact 1/60th of a second a number corresponding to the

5,000 point prize would be the selection *and* had the timing to activate the correct joystick input at that exact 60th of a second, that player would be able to make nothing but Banannas appear throughout the whole game. But of course this is not humanly possible. So basically the game uses human inconsistency to randomize the prize output.

There is however an anomaly in the odds. Each of the 7 bonus prizes *do not* have a 1 in 7 chance of appearing because of the way the Ms.Pac-man programming code was written.(See below)...

Cherry 0 7 14 21 28 Strawberry 1 8 15 22 29 Orange 2 9 16 23 30 Pretzel 3 10 17 24 31 Apple 4 11 18 25 Pear 5 12 19 26 Banana 6 13 20 27

The register runs through all 32 incriments in just over half a second. As you can see, all prizes have corresponding numbers. The sequence goes from 0 to 31, and continually repeats without a pause, skip, or reset from the time the game is powered on to when it is powered off.

***Unfortunately, the high bonus prizes(Apple, Pear, & Bananna) are shortchanged in that last line. So as a result the average complete game score is 874,342.5 points instead of the 905,280 points that it would be if the odds were in fact 1 in 7 for each prize. The *actual* odds of getting each prize is shown as fractions and percents here:

Odds of Appearance

****************** Cherry 100 points = 5/32 = 15.625% Strawberry 200 points = 5/32 = 15.625% Orange 500 points = 5/32 = 15.625% Pretzel 700 points = 5/32 = 15.625% Apple 1,000 points = 4/32 = 12.5% Pear 2,000 points = 4/32 = 12.5% Banana 5,000 points = 4/32 = 12.5%

As I mentioned consistently reacting within 1/60th of a second is not possible, but 1/20th of a second can be achieved with *relative* consistency, which should be enough to shift the scoring odds ever so slightly. I say 1/20th because the numbers representing the high value prizes(Apple, Pear, and Bananna) run through the register within that amount of time. Determining the exact instant this happens will be possible through a series of visually references. Since each maze produces two prizes, and the speeds of game's character movements are consistent throughout the game. And since we have and can create maze patterns that run from before the appearance of the first prize to after the appearance of the second, the exact time the first prize appears, what it is,and possibly it's travel pattern will make it the reference for determining what adjustment/s will have to be made before the second prize appears.

***So the last joystick movement before the dot that triggers the second prize will be the key.

Since our maze patterns have a lot of pauses, the possibility of resuming motion at the exact same time a particular second on the display clicks over is doable with some accuracy above and beyond rolling the dice.(It's a matter of how many times we can hit this high speed window over the course of a 5 or 6 hour game).

Even a 25% accuracy of hitting that 1/20th of a second window will add an average of over 45,000 points to one's scores, with a large deviation either way.(This is rough math). This would greatly increase the probability of moving the world record up on the game.

Also, another idea involves aiming for the larger 27/60th of a second window that the prizes do have an equal chance of occurring, thereby effectively cutting out the register numbers of 28 to 31. This of course would be much easier to do, and automatically adds about 31,000 points to one's average score.

As far as drift in the game's hardware timimg, this has already been considered. But still adjustments can be made by noting the first specific prize, and then making adjustments for the second prize.

The bottom line is that there will be a lot of human error as far as timing is concerned, but the player with the *least* amount of errors should have a higher scoring average over time.

***So it is logical to want to minimize the inconsistency of whatever timing device is used for reference as much as possible. A second on the display that doesn't click over accurately within 1/60th of a second will add it's deviation to that of the human errors which will already be plentiful. So obviously, the more accuarte the timer is, the better.

Now that was the dumbed-down explanation of my already twice simplified project.(I'll have to work my way back to the automatic pattern generator in the future).

Darren Harris Staten Island, New York.

What would occur to me first is to replicate the game on a PC and build whatever timing or scoring you need into the PC software.

N

[Perhaps drop the newsgroup that isn't sci.electronics.design]

snipped-for-privacy@mail.con.com wrote: [snip scoring and anomaly stuff and prize %'s]

...

...

I didn't see where game hardware timing drift was considered. Did I overlook something about drift in what you wrote?

Anyhow, this timing problem looks complex enough -- it looks like the timer may need to slightly speed up or slow down, or to keep track of scoring and joystick events -- that the best approach would be a PC- or micro-based timing program. Let PTP="PC timing program".

You want PTP to provide a seconds metronome, to signal the Banana zone of each second. To make it actually work, I think PTP would need to know timestamps and values for your joystick inputs and for scoring. (See * re getting this info.) With that data, PTP can get syncronized and accomodate for drift. For example, suppose you do some joystick movement x and then 5 cycles later the score goes up 500 points; this tells PTP Orange was on the bonus timer 5/60 seconds ago. After a while PTP can figure out where Ms.Pac-man is in its 0...31 bonus timer cycle. If, 123 seconds later, Orange is showing up a cycle early relative to PTP, then PTP increases its per-second delay count by 1 part in 60*123. PTP should have an adjustable reaction-time offset for different players. PTP probably should start with a half-minute or so synchronization phase, and re-sync whenever player tells it to.

• Getting event data: Of course you could set up a board with several pushbuttons on it and enter data that way, or have an assistant do so. This might work if you don't have to sync very often. Also you could attach mercury-switch sensors to wrists or perhaps to an elastic band that fits on the joystick. For definitive scoring detection, aim a TV camera at the screen area where score appears, and decode it in real time. Or if the game is running on the same computer as PTP, your program can monitor some bytes of screen memory.

-jiw

Incidentally, regarding the $49 ebay item

(Datum bc620AT ISA time and frequency counter card) that I mentioned a few days ago, there is a manual for it at . This card looks fairly involved to program, and if you were to use it I'm not sure whether it would be better to use the programmable frequency output (pp. 38-39, p. 51) or the time coincidence strobe (p. 31) or the 1 pps output (p. 11). Stability is listed as < 2 ms per hour; long term accuracy can be improved by inputting a 1 pps signal from a GPS unit.

-jiw

Next time, say that to a girl... Or better yet, about a girl behind her back ;-)

--
Met vriendelijke groet,

   Maarten Bakker.

Yes you did. Whent you mentioned drift five days ago, I said, "I'm aware of the consistency of the game hardware. And this project can't involve tapping into the games clock."

Thanks for the advice but this has to be a "real world" experiment. As I mentioned it involves going for the world record on Ms.Pac-man, so the gaming hardware cannot be tapped into to or changed in any way. The player is the only interface, and info can only be received visually from the games monitor screen and the the timer's display. This all comes down to human timing.

BTW Here is some info I uncovered on that acrd you mentioned: "When DM2000 was first released in 1996, the time synchronization hardware used was a Datum BC620AT card and time synchronization software from the Windows NT* Server Resource Kit. The hardware had a potential problem with the GPS week rollover issue. This time synchronization software has not been tested by the vendor for year 2000 issues. As a result of these issues, and because the system was difficult to set up, we no longer offer this solution."

Darren Harris Staten Island, New York.

Thanks for the judicious snip. :-)

You can get the source code here:

but you have to have a license for the ROMs. I think I have a de facto license for game ROMs, since I used to repair them for a living, and the company copied them routinely so the owners/ operators could have spares.

Pac-Man, however, for some reason, is almost impossible to find, unless you have an actual physical game that you can pull the ROMs from - and if you have that level of access, just solder a wire onto the nearest clock, and clock your joystick sniffer in sync, or whenever you want to.

Lessee....

Have Fun! Rich (I also once had to fix an NSM jukebox... ;-) )