Tell us the symptoms. Is the screen only white for a long time, and then finally the gameboy logo shows up? Or does it just start with regular speed? Does it even turn on at all? What gameboy are you using?

Starts with regular speed. Always. Regular GBA

Managed to do it. although my crappy flashcard can go up to 6 MHz

Can an overclocked GBA playing pokemon trade with a non-overclocked GBA?

When I turn on my DS with the overclocking turned on, my DS flash card does not work (it acts like you don't have the micro SD card inserted). Different flash cards probably have different effects when you try running them on an overclocked system. Every official GB, GBC & GBA game that I have used in my overclocked GBA works fine.

gamemasterful
I don't know if you could trade Pokemon between an overclocked and a normal speed GameBoy. You would have to try it to find out. I tried connecting my overclocked DS wirelessly with a friend's normal speed DS to play Mario Cart or Mario Party (I forget which), but it could not connect, so I had to change back to normal speed.

I figured it wouldn't, since the signals would be a double (or whichever) speed, and the other GB's would still be at normal, and therefore couldn't read it.

Hi, first thanks a lot for this realy good guide on overclocking a gba.

I was about to do the same to my gba SP but... its so damn compact and I cant find any guide specific for the SP either, and it seems like the only option is to make a "external" mod of it
Anyone got a thought about it?

And is there anyone that figured out what exactly happens with the values when you put crystals parallel to one another?

You can find an example of the GBA SP being overclocked at the Japanese site below.
http://nds.jpn.org/jittsaini.htm
Translatedhttp://babelfish.yahoo.com/translate_url?doit=done&tt=url&intl=1&fr=bf-home&trurl=http://nds.jpn.org/jittsaini.htm&lp=ja_en&btnTrUrl=Translate

Basically, it works the same exact way as my instructions for the original GBA, but you just have less room for components.

You could make an external mod pretty easily by just soldering a wire to each contact of the Oscillator Crystal on the SP's board, and then running the wires out a hole (or two) that you drill in the side. Then you could attach a crystal to those wires to overclock your SP. If you want to make it pretty contact, just find a connector that has two contacts spaced about the same distance apart as the crystal's leads, and wire the connector so it just barely sticks out a hole in the SP's case. you could plug the crystal into the connector, or if you don't want to lose it as easily, you could make something larger that contains the crystal wired to the mating version of the connector you wire into your SP.

Placing two crystals in parallel is how I and many other people performed our overclocking mods. I don't know the exact circuit calculations of why it works that way, but usually the Game Boy runs at the speed of larger of the two crystals connected to the same contacts.

how do you find the mhz of an ocilator

View My Video is this an oscillator it says

15.5766
B 5 C H
KDS 1H

and is it possible to swich between the original oscilator and a faster one

Can you post a picture of it? Videos are blocked at my work computer.

If this is an Oscillator, then the 15.5766 would mean 15.5766 Mhz. This may be a little too fast to use to overclock a GBA since the original crystal is 4.194Mhz. You could try it, and if it doesn't work, you could find a different oscillator crystal that is closer to 8Mhz.

If you read this "Overclocking your GBA" thread, starting at the first page, it will tell you how to switch between the original oscillator and a faster one.

sorry ill post a pic i had to use my flip caue i was in a hurry and im overclocking a gbc and you said that was 8mhz

If you want to overclock a Game Boy Color, a 15 MHz oscillator should work since the GBC has faster crystal than the GBA. If you can take a picture, or save a screen shot from the video ("print screen", then paste it into Microsoft Paint, crop it, and save as a .jpg or .png) I'll see if it looks like a kind that would work. It most likely should have only 2 or 3 wires unless it is a surface mount component like what is on the GBA or GBC boards.

It'll work, it's the same style as the one you pictured in your guide.
15.5MHz will be about a 200% overclock, which leaves plenty of control for games like Pokemon (I haven't tried any other games).

will a variable oscillator and variable resistor work for a speed adjuster

The Crystal is just part of the timing circuit, so most likely, if there was a "variable oscillator" you would need to modify some of the other components. I don't really know. If you have a variable oscillator or variable resistor/potentiometer, then go ahead and try them out. You just need to be willing to take the risk to mess up your GBC if you get it wrong.

While I don't understand all of what I have read about oscillator circuits, it sounds like the capacitors have an affect on the timing. Someone would probably need to find what components are part of the oscillator circuit if we are to figure out how to make a variable oscillator.