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Chicago

hey guys!
So I recently bought a modded gameboy on eBay, and it was very cheap (20$) but all in all a good mod. it had a backlight, internal prosound, and a variable clock mod. the only problem is that there is no off switch for the clock mod.

so, since i will probably never need it, i would like to know how to remove it.

thanks!

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Taichung, Taiwan

Step 1: Open up Gameboy.
Step 2: De-solder variable clock components.

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Sweeeeeeden

If the clock crystal (indicated in the picture) is still in there, you should be able to just desolder the mod and it should work normally. If not, you need to replace the clock crystal with a new one (or one nabbed from another Gameboy). If possible you should get a replacement one that is exactly 4.194304 MHz. If not, you can use a 4 MHz one or any value in the vicinity, ordered from any electronics part distributor like Mouser. Using a different clock crystal than the stock value will offset the note pitches and BPM values, however. This can be fixed with a ROM modification, though.

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perth, WA

i'm curious...how much leeway does the ROM modification give you?

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Sweeeeeeden

All the leeway you want, basically, with one caveat. With an original close to 4 MHz clock, the lowest possible frequency (because of hardware limitations) corresponds to about C-3. No problem. With a close to 2 MHz crystal, it would instead be C-2, which is just one octave below. (Often done to gain an extra octave of bass.) Also no problem.
If you put in say a 3 MHz crystal, the lowest frequency would be something G-2. You now have a couple of options. Make the scale start at G-2. Map everything to their true notes starting at C-3, and ignore the newly available half octave below C-3. Map everything to their true notes starting at C-2, but map C-2 to F#2 (or so) to the frequencies one octave above. It can be a bit extra tricky, but anything is possible, really.

Things to keep in mind though, too low clock frequency, LSDj or other software may run too slowly to play your song without lagging. Too high frequency, and you put a limit on how low notes you can play, and also, there's some limit on how hgh frequencies the CPU can tolerate.

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West Yorks, UK

man just swap it with someone who wants the clock mod? seems a shame to waste it!

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If it's already in there why not just add a switch to it? The effort of removing it couldn't be much more than throwing in a switch.

EDIT: If it is a variable mod and the board is separate above statement stands. Otherwise I rephrase this to... "Can we get a picture of the inside?"

Last edited by Adil Soubki (Jun 12, 2014 11:32 pm)

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Sweeeeeeden
Adil Soubki wrote:

If it's already in there why not just add a switch to it? The effort of removing it couldn't be much more than throwing in a switch.

Yeah, but adding a switch is also a risk. The switch may break during a gig or make the GB more crash-prone.

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Chicago

my soldering skills are pretty weak. could i just cut the wires, or would that cause issues?

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Matthew Joseph Payne

You should be able to just cut them. If you have nice, angled cutters, you should cut them as close as you can to the board (close to flush if possible). If not, cut them longer and cap the wires off with heat-shrink or electrical tape.