GBC Turbo 2

themadhacker · Post by **themadhacker** » Sat Nov 22, 2008 10:05 am

Presenting my GBC Turbo 2. This is my second overclocked/LED modded GBC, only this time, it uses a 14 mhz crystal and orange and red LEDs.
pic!

BTW: this is the one in my for sale thread.

eurddrue · Post by **eurddrue** » Sat Nov 22, 2008 12:57 pm

nice!

you beat me to my first one lol.

nitro2k01 · Post by **nitro2k01** » Sat Nov 22, 2008 2:56 pm

Is it stable when running at 14 MHz? It's over a 3x overclock! Games using the GBC double speed mode will ru at a throbbing 28 MHz.

eurddrue · Post by **eurddrue** » Sat Nov 22, 2008 3:40 pm

I think that someone used a 69mhz and said it overclocked only about 4.5 times and then wouldn't go any higher. Yes it is stable at 14mhz, skyone reccomed about 16mhz.

Kyo · Post by **Kyo** » Sat Nov 22, 2008 4:14 pm

overclocking a gameboy... mhmmmmm

I like that idea. I like it a lot. Nice mod, I think I might just do it myself anytime soon.

themadhacker · Post by **themadhacker** » Sat Nov 22, 2008 4:42 pm

nitro2k01 wrote:Is it stable when running at 14 MHz? It's over a 3x overclock! Games using the GBC double speed mode will ru at a throbbing 28 MHz.

actually it is a little less than 2x original speed. unlike the other gameboys, the gbc has an 8 mhz crystal as opposed to 4 mhz.

Thanks for the comments guys, I appreciate them!

nitro2k01 · Post by **nitro2k01** » Sat Nov 22, 2008 5:56 pm

themadhacker wrote: the gbc has an 8 mhz crystal as opposed to 4 mhz.

Incorrect. The GBC has a 4 MHz crystal, just like the old DMG. But it has a special double speed mode that triggers both on positive and negative edges of the pulses. That way you effectively double the speed. But maybe this double speed mode doesn't work too well with a 14 MHz crystal.

themadhacker · Post by **themadhacker** » Sat Nov 22, 2008 6:23 pm

well, on the three( overclocked another one a while ago) that I overclocked, everythng works perfectly.

Arrow--> · Post by **Arrow-->** » Sat Nov 22, 2008 8:05 pm

you overcloked my GBA with a 13 and ruined it

Ok it was my fault too

themadhacker · Post by **themadhacker** » Sat Nov 22, 2008 8:11 pm

it still has the old crystal, doesn't it? Or does it not work at all?

Kyo · Post by **Kyo** » Sun Nov 23, 2008 1:17 am

nitro2k01 wrote:
themadhacker wrote: the gbc has an 8 mhz crystal as opposed to 4 mhz.
Incorrect. The GBC has a 4 MHz crystal, just like the old DMG. But it has a special double speed mode that triggers both on positive and negative edges of the pulses. That way you effectively double the speed. But maybe this double speed mode doesn't work too well with a 14 MHz crystal.

A special double speed mode?

Where can I find more information about that?

nitro2k01 · Post by **nitro2k01** » Sun Nov 23, 2008 8:04 am

Kyo wrote:A special double speed mode?

Where can I find more information about that?

It's a standard thing on the GBC, so it can't be used to artificially boost a normal game. It's a feature in the hardware that GBC software can use if it wants to.

Information about it is available in the Gameboy development document "pandocs" which is currently offline. However, I took the time to add it to my GB development wiki. (I was going to add it at some point anyway)
http://gameboygenius.8bitcollective.com ... eed_Switch

And to point it out clearly, this info is only useful if you're coding your own GBC game.