I have recently built a portable game system that lets you play 12* TOTALLY RADICAL Namco games such as Pac Man, Dig Dug, and all that good stuff.

Now, I want to make five things perfectly clear before we begin...
1) This is my first instructable. :3
2) No matter how much you hate this, please refrain from being negative.
3) I'm not responsible for any mishaps that may happen whether its a burn or an explosion.
4) I'm so very sorry...I didn't exactly take pictures as often as I should have, so I'm going to have to assume you can find screws and such ;)
5) Enjoy It! Now onto the instructable! PULL THE STRING!!!

*11 are compatible

Step 1: General Idea

There are five main components to a portable system.

1) The Screen
2) The Game
3) The Controls
4) The Battery
5) The Enclosure

I used this as my LCD screen because it was cheap, small, and accepts the right input.

I found this thing at Goodwill for 2 bucks. Score!! :)

The A, B, and Pause buttons came from an NES controller. The Directional Buttons are these cute things.

The screen takes 12V, and the game takes 6V. Very different voltages (we will fix this later) and obviously you don't want 8 AA batteries weighing your handheld down! So I got a 12V rechargeable Li-ion battery from eBay.

I chose a RadioShack 6x3x2" plastic project box because it is durable and easy to cut.

You also need a soldering iron, a hot glue gun, a dremel, and a drill.

Ready to begin? Let's roll.

Step 2: Open the Screen

Our Screen is nice, but it is much too big, as the company did not make this product specifically for us to tear apart and use for videogame screens.

BUT WE'LL SHOW THEM!!

First off, on the back of the screen there is a big stand used for mounting the screen on a car dashboard. This takes up space and will be useless in our enclosure, so pull it out. It's not attached to anything.

Now, use a screwdriver to unscrew the four Phillips head (+) screws on the four corners of the system. Pull the back off. You will notice that the wires that lead to video and power are preventing the back from being fully removed. Use your soldering iron to remove the four wires on the board (Yellow, White, Red, and Black, respectively) and you can now remove the screen. There will be no need to save these wires.

Now for the tricky part. The screen itself is glued to a very large piece of plastic that keeps the screen from getting scratched. Which is nice, but it takes up WAY too much room. Very Carefully remove this from the silver border around the screen. I messed up when I did this, which caused me get nearly 40 dead pixels on my screen, which is painful. When its removed, simply use scissors to cut off the extra parts of the protector. Okee Dokee? Let's go on.

Step 3: Open the Game

Thankfully, the game is a million times easier to open than the screen.

Remove the battery cover and remove the batteries.

Use your screwdriver remove the four screws that hold the system together. Open it up.

Remove the Red and Black wires that lead to the battery case.

Unscrew everything that's holding the blue boards in place.

Step 4: Replacing the Buttons

Remember when I said to get those cute RadioShack buttons in Step 1? Time to use them. Desolder the switches that look like this, and leave the switches that look like this.

Now, in place of the switches you got rid of, put the RadioShack buttons in. these are much nicer and feel more "directional paddy" for a handheld.

FUN FACT: I just got bored writing this, so I played a bit of Dig Dug. MAN, was it fun.

You should solder the switches a bit something like the nice picture I provided. AREN'T I GOOD AT DRAWING?

Step 5: Voltage Information

Note: Here, I'm stating basic electronics information of how to make safe circuits and how to check if they're safe. If you know how to use a multimeter and why short circuiting is bad, you may skip this.

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WARNING: Never ever ever ever let the positive and negative of a battery touch directly! The battery will smoke and explode! Which is kind of cool, but then you can't use it.

ANOTHER WARNING: Too many volts will cause some electrical components to smoke and eventually catch on fire! Don't let your components smoke and catch on fire! Because when they do, they're dead! They aren't coming back! Understand?

You see that blurry picture I added for your viewing continence? That's a digital multimeter. It measures the amount of volts in a circuit (and morrrrrrrree). Simply put the red on the positive and the black on the negative and you will get a number of volts. Always do this before wiring things, at the risk of messing it up. Now, let's go on.

Step 6: Wiring the Battery

Now, with a 12V battery, you can absolutely run the 12V screen! But how will you run the 6V game?

Very simple...you need a 7805 Voltage Regulator! That will convert 12V into 5V (which will run the 6V machine). You can get this at good ol' RadioShack.

Note: This is the most important step. If you mess this up, you messed it up.

Picture 1: A basic drawing of how to wire everything.
Picture 2: Where to wire on the LCD
Picture 3: Where to wire on the Game
Picture 4: What mine looks like

Step 7: Getting Video / Audio

Find the wire that is labeled "VIDEO" and solder it to the screen. The screen has two inputs, pick whichever one your heart desires. Don't forget to wire ground to ground.

Now, for something a tad more complicated. Audio. I chose not to have speakers, but rather just a headphone jack, because I knew I'd just use that. If I wanted speakers, I'd simply plug an amplifier into the headphone jack and problem solved.

Something to note about audio is that it is rather quiet. The reason for this is because it relies on the TV's volume control to make it louder. But we don't have a volume control, so if we want speakers, we need a built-in amplifier. However, for headphones, the volume is perfect. So...I'm going with headphones.

Also, when you wire the headphones, you will notice that the sound will only come out of one earbud. We want both, so solder an extra wire to do so.

Picture 1: LCD Wiring
Picture 2: Game Wiring
Picture 3: Headphone Wiring

Step 8: DRILLING TIME

Congratulations, Human Worm Baby! You have successfully soldered everything in place! Now test it out! Fun, huh? Well, we're not done yet! It's time to fit everything inside the small case you picked out! YAY!

Now, clean off your area. (Picture 3) Get out your drill, and put a hole for the headphone jack, Charging Base, Power LED (if you choose to have one) and overall, switch to turn it on. Hold these in with some hot glue.

Step 9: Cutting the Hole for the Screen

Take the faceplate of the enclosure and measure the screen. Mark areas in pencil and cover it all in masking tape. Put edges of the tape on where you're cutting. Why are we doing this? Because dremels are easy to control, but if we slip, we'll make a very big scratch and it'll make your system look ugly. SO DON'T DO IT.

Take out your dremel and drill around those areas. Poke at it and a piece of plastic should fall out revealing the screen area.

It should be very bumpy along the edges, so use a needle nose pliers to take out the big chunks and a rasp to flatten it.

Step 10: Drilling Holes for Buttons

Now that you have that done, drill holes for buttons. You need the four directional buttons, A, B, and a Pause button. I chose to not include the potentiometer that plays Pole Position because it takes up a lot of space, and I couldn't figure out where to mount it. Pole Position can be played, however it is impossible to turn, which makes the game useless. But I'm okay with Pacman ;)

I salvaged some buttons from my old broken Portable NES console (which salvaged the same screen from, actually) and crammed them in.

The design is simple...hot glue A and B to the far right, put buttons on top of them, and test it out. The Start button is a little harder, but don't worry...you're almost there!! Hot glue the directional buttons and LCD Screen to the top of the case, and then put the lid back on. Put screws in, and realize...you've made a portable game system!!

Step 11: Aftermath

I never knew I liked Dig Dug so much.

Anyways, it's time to list the good things and bad things about my work, completely honest.

GOOD THINGS
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Portable System, 11 Built-In Games!!

Fits in your hands much easier than my other portables

Small and Lightweight

Rechargeable Battery

BAD THINGS
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The Directional Buttons often get stuck, this problem is solved by taking the red and black caps off, however it's less comfy.

There's a giant hole at the top, this was going to be for a potentiometer *FIXED*

There's about 40 dead pixels on the screen.

The A button handles much better than the B button. *FIXED*

The power switch can often get loose, resulting in accidental turnoffs. *FIXED*

THINGS I CUT OUT
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Mentioned several times, there was going to be a potentiometer to play a game. Removed for space.

Instead of on the top, there was originally going to be a side attachment that would plug into the left, revealing the potentiometer.

I thought of putting two Plug in & Plays into the system that would alternate with a switch. This would make wiring controls hard.

On the top there was going to be a jack that would let you play the game on the TV. Removed to make wiring easier. *EVENTUALLY ADDED*

UPDATE 7/19/12
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This has been up for a week, it has over 3,000 views and has been featured. Thank you, thank you thank you!
I plan to fix these problems in the upcoming Step 12.