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Overclock Mac LC II?

Posted by: Brooklyn on 2024-05-31 21:08:32

Hi, wondering if anyone has successfully overclocked their LC II? I’ve tried swapping out the oscillators, changing the 25.175 one makes no difference, changing the 31.3344 speeds up everything including messing with the sound (higher pitch) and video refresh.

Any way to just speed up just CPU?

Thanks!

Posted by: danny.gonzalez.0861@gmai on 2024-06-01 16:34:01

Seems like the Low End Mac page shows your same issues and they ended up upgrading the MB to a LC III. Unfortunately you might have limited options with your current setup.

If I were you I would leave things as is and maybe look for an LC III as a new project to tinker with.

Posted by: Byrd on 2024-06-01 17:35:43

Even if you can overclock an LC or LC II, you're just making a very slow Mac very slightly less slow. Maxed with RAM, a nice HD, they are still pretty good for Mac OS 6, 7 and early colour games though.

Posted by: GiGaBiTe on 2024-06-08 20:28:34

There is no easy way to overclock an LC II and not have other things affected on the logic board. The easiest solution would be a logic board swap, or installing a PDS card processor upgrade. The downside with this is that if you have a network card, you have to choose one or the other.

Someone has reverse engineered one of the Micromac LC/LC II/CC accelerator boards and made replicas. This will get you a 32 MHz 68030 with a 68882 FPU.

MacEffects Thunder PDS 32Mhz Accelerator for Apple Macintosh Color Classic and LC II

MacEffects Thunder accelerator is the perfect hardware upgrade for your Macintosh LCII (Performa 400/405/410/430) or Color Classic computer. The Thunder accelerator features a 68030 processor and 68882 FPU (math coprocessor) both clocked to 32Mhz to speed up CPU performance and math...

maceffects.com

Just remember that this faster CPU is still hobbled on a 16 bit, 16 MHz bus, so it won't speed up other parts of the system. For the price of this upgrade, I'd recommend a logic board swap instead. If you can find a Quadra 605 for a reasonable price in a junk case, you can recap the board and swap it in your LC II machine.

I did a Quadra 605 upgrade to my LC III and the performance uplift is substantial. I overclocked my Quadra 605 to 40 MHz and installed a full 68040, so it's a screaming little machine.

Posted by: mg.man on 2024-06-09 01:48:16

The easiest solution would be a logic board swap, or installing a PDS card processor upgrade.

Our own @max1zzz may have just what you need :

Thread 'FS: LC (II) Plus - Combined LCII / CC Accelerator & Ethernet card' https://68kmla.org/bb/index.php?thr...ined-lcii-cc-accelerator-ethernet-card.47380/

Posted by: GiGaBiTe on 2024-06-10 03:59:33

Nice, so you can have the best of both. If he ever gets around to adding cache to the upgrade, it'd make it a whole lot snappier on the crippled 16 bit bus.