Mac Clock Chipping!

Do you have a technical question that doesn't really fit a specific console? Want some general info on electronics, hacking, making cookies, etc? Here's the place to ask! Go nuts.

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ArtemisGoldfish
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Mac Clock Chipping!

Post by ArtemisGoldfish » Mon Sep 04, 2006 1:14 pm

Has anyone here tried overclocking an old m68k Mac? I'm looking to see if anyone has any experience doing before OCing my 33Mhz 68LC040 to 40Mhz.

Might not be the best forum to ask on, but it's worth a shot.
Logan Whitehurst, Musician Supreme
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sgtpepper
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Post by sgtpepper » Mon Sep 04, 2006 1:26 pm

I haven't, but I've been thinking about overclocking my old Macintosh SE (a blazing 8 MHz right now). Post pictures of your progress please!
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bicostp
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Post by bicostp » Mon Sep 04, 2006 1:57 pm

You can replace one of the oscillators in a IIsi to bring it up to IIci speeds.

Desolder the 40mhz oscillator closest to the SIMMs. Be careful because the board is multi-layered and you don't want to overheat it. Now solder in a socket that can handle the oscillators, and slip in the new one. Reinstall the motherboard and fire it up. Don't close the case until you've played withit a while.

This will boost the IIsi from 20 to 25 mhz.

^ I just pulled that out of the old Spring 1993 BMUG newsletter. I'm sure you could figure something out for other models. Just don't push the 68k processors too fast, like anything they have their limits.

I think the fastest non PowerPC Mac is the Quadra 840AV (40 mhz '040), but I could be wrong.

ArtemisGoldfish
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Post by ArtemisGoldfish » Mon Sep 04, 2006 3:40 pm

Finished it, I'll yank the mobo out again and take a few pics. The LC63X's could be overclocked by just changing a few surface mount resistors, which ended up being nerve wrenching, but not too hard. Yanked the resistors off their current seats with a desoldering tool, and soldered them back on to the other points (as is instructed on various websites). It's booted up, and I'm watching Little Shop of Horrors on it through the Coaxial Video-in hooked to a VCR. I also ran Marathon Infinity and it seems to run well, but I'm not sure if it gained much of a speed boost.
Logan Whitehurst, Musician Supreme
R.I.P. (Deceased Dec 3, 2006)
You are missed.

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