Info about the LEDs on my 6-Slot (light up depending on which game is selected)

[Flavor]

I made a video of the LEDs in action. There's a QuickTime MOV file that's almost 5 megs and a low-quality RealMedia RM file that's about 100k. If you want to check out how it works, head over to
<a href="http://www.personal.triticom.com/~erm/Arcade/NeoGeoUprightPics/" target="_blank">my Neo Geo MVS 6-Slot pictures</a>.

I don't know if anyone really cares that much, but if anyone else is interested in doing this, feel free to ask. I don't mind explaining it, but I won't go into detail unless someone else actually wants the information.

Oh, and if you want to read the original thread about this, it's <a href="http://www.neo-geo.com/cgi-local/ultimatebb.cgi?ubb=get_topic&f=5&t=003411" target="_blank">here</a>.

 

[chris1]

Good job.

 

[Briggs]

Very cool!

How about some pics showing the LEDs themselves? I would be very interested to see a description on how you did it.

Thanks!

 

[Flavor]

Well, I had to borrow a camera to get the pics that I took, so it's not easy for me to get more pics.

BUT, I can describe what I did.

The LEDs are 10,000 mcd (milli-candellas I think). When they are off, they look completely clear, but when they're on, they glow red. I really doubt it matters much, though. Just get something bright.

For the mounting, I put a few strips of electrical tape on the back of the clear plexiglass mini-marquee holder. You know, the thing that the mini-marquees actually slide into. After that, I marked the middle of each mini-marquee and put a dot about 3/4 of an inch above each mini-marquee. I just kinda guessed on the right height so that the LEDs would be just behind the numbers.

Then, I took my smallest drill bit and drilled 2 holes for each LED (because they each have 2 "legs"). I drilled through the clear plexiglass and through the electrical tape that I just laid down.

For the LED wiring, I chained all the NEG leads together. Then, 6 individual wires go to the POS leads of the LEDs. All these wires run behind the electrical tape, so they don't make shadows on the marquee. Oh, and I used CAT5 networking cable to wire it up, because I'm a computer guy and have a bunch laying around.

So, in my next post, I'll describe how I wired into the ELA board. It's pretty simple, though.

 

[Flavor]

The logic on the ELA board is fairly simple. You could build the same logic very easily. It would probablly cost around $5 for all the parts.

BUT, my ELA board had all the logic I needed, so I figured I might as well use it.

The ELA is somewhat separated into 2 halves. The first half is the input side. It has 4 logic IC chips. It's all digital logic on that half.

The second half is the half of the board that's close to the outputs (that would normally go to electro-luminescent EL panels). This half of the board converts the +5DC voltage into a high-voltage AC (that the EL panels use).

I pretty much just ignored the second half of the board and focused on the first half.

I tapped into the digital logic right before it went to the "second half". There are 6 resistors on the board, and if you look at the bottom, you can see that each resistor has a trace that runs to a transistor on the second half.

I desoldered 1 leg of each resistor so that the output of the digital logic would go through the resistor, but would not continue on to the transistor.

So, I had 6 resistors sticking up in the air. If you solder a wire to the end of the resistor (that's sticking up), you can wire it to the POS side of a LED.

Is that clear enough? Is there anything you need more detail on? I have the spec sheets for the 4 logic ICs, and I can probablly get detailed pictures in about a week (after Thanksgiving).

 

[Flavor]

Oh, I forgot to mention that the LEDs I used take 2.4 volts. They seem to work well in series with those resistors I talked about.

 

[Briggs]

Is this possible to do if the EL panels are working as well, or can you only have one or the other?

 

[Flavor]

Well, I tried to wait until my electrical engineering co-worker showed up, but it looks like he's out for the day. I'm fine with the digital logic part, but I usually talk to him if I need real-world info.

Anyway, I can think of a few ways that you could do it and keep the EL panels on there. I can't guarantee if it'll work, but it should be easy enough to test.

Take a look at this picture.

You can probablly solder the 6 wires on to those points without desoldering anything. I would test it first. You should be able to get an aligator clip on the leg of the resistor on the bottom of the board. The 1-6 shown in that pic are the side of the resistor that comes from the logic IC. They are not the side of the resistor that goes to the transistor. You might need to put a new resistor in series with the LED. Someone else might shed some light on this. If you just slap an LED in there, it might adversly affect the rest of the circuit.

The other way that I think it would work is to make your own LED control board and make a Y adapter so that one fork went to the ELA board and the other fork would go to your LED control board. Obviously that's more work.

And, finally, I THINK (not incredibly sure offhand) that my modified ELA board will still light the EL panels. It just won't brighten up the currently selected game.

 

[Flavor]

Okay, I think I got it.

I think that if you use those solder points, you should be fine. Just put a 85-100ohm resistor in series with your 20mA LED.

So, I suppose what I would do is to solder one leg of a 100ohm resistor on to each of the 6 solder points.

Then, solder your wire on to the other leg of the resister that you just attached. Run the wire to the POS side of your LED, and run the NEG side of the LED to NEG.

In theory, that should work, and you'd still have the EL panels intact. You would probablly want to try it with an aligator-clip setup first, though.

 

[Asure]

Ok, how about if i don't have this panel controller, do any of the points 1-6 run directly to the cable ?

I'm thinking of making a small piece of stripboard and doing some soldering

 

[Flavor]

Nope. Those solder points that I labeled don't run to the inputs.

But before I go on, is the <a href="http://www.zonko.nl/gallery/view_album.php?set_albumName=album04" target="_blank">http://www.zonko.nl/gallery/view_album.php?set_albumName=album04</a> page yours? I might have some pics to add.

You could make your own board pretty easily. I don't have the list here at work, but you'd just need to buy (and wire up) those 4 integrated circuit chips that you see in the picture. I'm no genius at this stuff, but if you give me a few days, I can come up with the info on how to wire the chips. I just don't know if I can help you with the capacitors and resistors. I am only good at the digital portion of it.

From what I have here, these are the 4 chips that are used, in order of their use from input->output.
HD74HC14 (evens out the "clock" line)
HD74HC174 (latches the input)
HD74LS138 (decodes the inputs)
SN74LS368an (can sink more current, I think)
You should be able to find PDFs of these if you search on Google.com.

I'll try to get a close-up picture of the ELA board, too. Then you can get a better idea how it all works.

Oh, and Briggs! I got another idea from my friend. Instead of putting your LEDs right at those solder points, consider wiring them through a inverter (NOT gate). Then, you will have an isolated place to put your LEDs and you can run the outputs to the NEG side of the LEDs. This means that (if you wanted), you could wire the POS side to the +5 line, and the LEDs could be brighter. Anyway, that's just an idea. It would take more work.

My guess is that you could build your own LED controller for about $5-7. The LEDs that I bought were just over $2 each.

 

[Asure]

Yup, <a href="http://www.zonko.nl" target="_blank">www.zonko.nl</a> is mine, although i'm probably going to transfer it to <a href="http://www.jamma.nl" target="_blank">www.jamma.nl</a> soon

If you have boot pics, you can mail them directly to me @zonko.nl, or provide me with a link, as i can let the gallery 'grab' it from a link if you provide one.

I'm also still after some AES bootleg pics, not modded carts, but real boots. I also spotted some pics in a recent thread but haven't bothered to add them to the page yet. Too busy modding pal snes & playing Seiken Densetsu 3 translation

- Alex

 

[Flavor]

Just a little update. I posted the info on a WWW page with some pictures showing the hardware.

<a href="http://www.personal.triticom.com/~erm/Arcade/NeoGeoUprightPics/LEDInstall/" target="_blank">Neo Geo 6-Slot LED Install</a>

[ December 05, 2002: Message edited by: Flavor ]</p>