LPT Switch

[cholin]

For 40 inputs, im sorry to say its not worth it.  You can get a real keyboard encoder with a reasonable amount of inputs for the same price.  With the switch its a good deal, and yes, im sure youll sell a few, but in this case, you'de be better off to just ditch the board because if you wanted one of these its better to BYO for a few bucks and get the full 60.

[Gamecab]

For 40 inputs, im sorry to say its not worth it.

[cholin]

Well I wouldnt be too sure about that.  If you sell those off for lets say $25-$30, its still a pretty good bargain, as long as you can get 60 inputs.  This will open up a whole new world for things other than arcades.  Im sure if you sold around 30 it would be worth it for you.

[Buddabing]

Well I wouldnt be too sure about that.

[Gamecab]

Ok,  Let's try this.  I'll etch out a 60 Pin proto-type board and put it togther to test on my Mame Cab.  If the results are good (I'm sure they will be) then I'll start a new thread to generate interest in this product.  If I can get enough people to commit to buy the board then I'll have them produced.
A good point was brough up by saying that this board is not just for Arcade related functions, so that is helping me sway away from Scrapping the idea.

Let me kow if this sounds ok?

Thanks
Charlie

[cholin]

Sounds awesome   Give it a go, but remember that when people say stuff, they don't necessarily follow through, as with your other board's thread   I like the idea though.

Just off topic, where do you get your boards made, and what/how do you create your prototype ones?  I was thinking of creating a board prototype using the "iron-on" method, but Im a bit worried that Ill mess up.  Not to mention that money plays a huge factor.

[Hoagie_one]

im not familiar with this iron on method, whats that all about?

[Trimoor]

You use a laser printer to print the circuit on special transfer paper, place this on the copper clad board, and press down with a clothes iron.  It should leave etchant resistant marks on the board.

I tried it a few times, but it never worked.  Half the traces never stuck the the board, and the rest had dozens of micro breaks in them.

There are also mechanical etchers/routers: a computer controlled router table for cutting small quantities.  They are horribly expensive to buy, but here is a link on how to build one.

[cholin]

You probably cheaped out on the paper for the iron method then, because I read some huge thing about it and it said staples paper worked wonders...ill find the site for you....

http://www.fullnet.com/u/tomg/gooteepc.htm

[Trimoor]

No, I used expensive stuff made specifically for this.  Maybe I should try photo paper.

[cholin]

Well check that site up there because the guy said it worked awesome, but if you use the iron method youll have to expect that youre gonna have to make a few touch ups with a pen later on...

[Gamecab]

I was just thinking that "Maybe" my CNC Router would be able to draw out the board with a fine tipped Sharpie marker.  I still have to try the Iron On first. 
Worst case, I'll make a few T-Shirts out of the design  (kidding)

[cholin]

If you do end up putting these into production, I would still like to know where you get them done.

[Lilwolf]

It doesn't sound like anyone is looking at this developming for others...

[Trimoor]

I don't think it worth $35-$40 if you can't get it working with anything but windows.
There are plenty of people who use DOS, and a stubborn few who use Linux (like me).

[Lilwolf]

I'm starting to second guess it also.  The real trouble is the quick disconnects.  You need 120 per setup.

If I sold it.  I would sell the base cable.  Then one per player (12 inputs).  Each players set of inputs would have 24 QD (2.50) let alone the cables or anything else.  So for all 60 inputes it would be 12.50 of JUST the QDs...  But your cabling would be finished!  Just plug and play.

Anyway, I want to create a prototype in the next week and see what people think after they are put together.

[Hoagie_one]

You know you can daisy chain the main 12 connectors each into 5 separate connectors so you dont have to have a 60 X 60 grid if you dont want.  Mine was a 12 X 60 grid but you have to daisy chain.

[cholin]

Well Im sure Peale would give you some type of deal if you decided to buy a few hundred from him.  Theyre usually $6/bag and I believe theres a fixed rate or a good rate for shipping...I was going to order 4 bags and I wanted to know shipping and he said a buck or two for all of the bags, so its pretty good.  You could do what Ultimarc does with the minipac and sell all the cabling optional for an extra 20+ bucks....

About the grid thing -- that depends whether you sell the cables too.  If you're selling cables for an extra few bucks, you would be better off 60x60, but otherwise, you would probably be better off just making the 5x12 like Hoagie said

[Hoagie_one]

Click here to see Wiring Diagram for my big bulky version

[IntruderAlert]

I haven't had time to actually look at it closely but I believe that this is an LPT CP interface in my Korean cab

[cholin]

Dont think so...  this circuit doesnt need any chips, its all diodes.  Is that from the korean cab?  You probably have some noname one in there, not sure though.

[Lilwolf]

I slightly changes the diagram... so that each group has a 'common ground'... I'm sure you can figure it out without much trouble.

IE, you cant plug the ground wire from player one into the positive in player 2. 

But after that... cabling looks like a common ground solution...

I was thinking that instead of trying to get a way to make the connections for the end user (screw in terminal or whatever) why not just wire them up... And after that I removed the board... And after that I rewired so there where only 5 different groups of buttons... And it all seems to be great....

but TONS of diodes... TONS of QDs... and TONS of heat shrink tubing to make it look good...

and after that...

I'm still worried about the drivers and the performance on a 4 player control panel with 4 buttons each if there will be any problems... but there is only one way to test it..

[IntruderAlert]

I'll try to crawl inside there and get a better shot of it tonight

[Hoagie_one]

i tested everything i could on mine short of hooking up a 4 player panel....I might still do that eventually.

[lustreking]

I've been looking at the schematic on Trimoor's page, and there's something I must be missing.  Where do you hook up the other contact for all those switches?  There must be a common ground somewhere, right?

-Steve

[Hoagie_one]

I've been looking at the schematic on Trimoor's page, and there's something I must be missing.

[Lilwolf]

Also, its not really a ground...   Just what we are used to calling it...

[Hoagie_one]

/\
|
|__what he said

[IntruderAlert]

here's a couple more shots of the LPT control board in my "Come On Baby" cab

[Trimoor]

What do all the wires plug into?  Does it control lights or other things?
Is the LPT plug the only thing connected to the main PCB?
Is the game X86 based?

[IntruderAlert]

Yeah.. if you click my sig you'll see that it's all run off of a Celeron 500
The red, blue, white, and unused plugins across the top of the picture all go to the CP

The LPT plugs into the port on the left of the XILINX chip

I didn't trace all of the other wires down yet
I was up till 4AM just cleaning the screen, taking and posting pictures, and tracking down a faulty wire.

I'll post more info when I can get back in the cab again

[Tiger-Heli]

Not trying to rain on this at all, I think it's a cool idea, but before someone tries to sell it commercially, I would like to point out a couple of other options:

USB - Two GP-Wiz Ecos - $40 and 64 inputs.
PS/2 - http://www.surf.to/buttonbox (approx $30 to build, and 128 inputs in matrixed mode).

[Hoagie_one]

yeah, unless teh whole thing clocks at less than $30, its not financially worth it.

But it was fun playing with it

[Tiger-Heli]

Another thought - looking at the schematic, it appears that the circuit is using a 12x5  matix with pins 18 to 25 of the connector unused.

Shouldn't it theoretically be possible to just add more diodes and wire and make this into a max 12x13 matrix (156 inputs), (more than the number of keyboard keys), or at least a 12x9 (108 input) controller?

What would need to be modified to make this feasible?

[brained]

The driver seems to only handle 60 inputs, maybe you need to modify the driver to handle all the inputs, anyways the drivers are open source so you can probably hack them 

[Tiger-Heli]

The driver seems to only handle 60 inputs, maybe you someone needs to modify the driver to handle all the inputs, anyways the drivers are open source so you someone can probably hack them 

[Hoagie_one]

assuming those other leads can be used in such a manner, i believe they'd just have to hack the driver to see a third joystick.  Cant do more than 30\stick i believe

[brained]

The driver seems to only handle 60 inputs, maybe you someone needs to modify the driver to handle all the inputs, anyways the drivers are open source so you someone can probably hack them 

LMAO!!!!!!!!!!
 

[Lilwolf]

btw, I was considering, but decided it wasn't worth the time, with a slightly modified version.

No boards.. just cords....

It took 6 VGA cords (can get in bulk for 1 buck each) and 1/2 of a 25pin m/m.

Then using heat shrink tubing and diodes, and a BUNCH of ends..

In the end... it would have been a 60 port prewired with swappable capablities (since the each group of 15 (really 12 but with a ground for that group and 3 not used) would be plugged in with the db15 monitor ends.


Anyway, seemed like a good solution.

[Hoagie_one]

local dollar store had LPT cables for $1.

thought about buying a bunch of them...but didnt