7410 on G3 ZIF Interposer Development Thread

[croissantking]

I’m musing the idea of creating a simple interposer to enable the use of a 7410 chip on an Apple G3/G4 ZIF without blowing out the cache controller.

Rationale:

- The 7410 is the ultimate Beige and Blue/White G3 upgrade.
- Both slower G3 ZIF cards and bare 7410 CPUs are cheap and plentiful.
- 7400s can be used without an interposer, but run too hot.

The key components of this mod would be:

- Design an interposer that brings out the 7410 chip’s L2OVDD pads to a solder pad in an accessible location.
- Select a small buck converter that can supply 2.5V to this solder pad, and figure out where this would mount.
- Lift/bend back the L2OVDD pins of the cache chips and route these to the buck converter.
- Design a new heatsink clip that accommodates the slightly raised CPU position.

Should be pretty straightforward, no?

 

[pizzigri]

That would be very interesting! using a 20€ 233 mhz ZIF G3 card to upgrade would be great

 

[obsolete]

This could also be nice for upgrading G3 upgrade cards for older Power Macs to become G4 upgrade cards. Then again, if you're going the interposer route, why not aim higher than a 7410?

 

[croissantking]

This could also be nice for upgrading G3 upgrade cards for older Power Macs to become G4 upgrade cards. Then again, if you're going the interposer route, why not aim higher than a 7410?

Which chip do you have in mind?

 

[herd]

You've seen the thread on the 750G, right?:

68kmla.org/bb/index.php?threads/ppc750gx-vs-ppc750gl.39043/

In my testing, a 1GHz 750G is faster than a 600MHz 7410 for most things. The G4 chip has altivec but the main improvement is 3-4x faster memory thruput vs the G3. I have not seen if anyone has tested this specifically on the Beige or B&W machines. The large, fast, on-chip cache of the 750G seems to make up for the slow memory in most cases.

7410 chips are also a nice upgrade. That would be neat to see. What voltage would you run the external SRAM chips at? Or would you move them too?

 

[croissantking]

You've seen the thread on the 750G, right?
68kmla.org/bb/index.php?threads/ppc750gx-vs-ppc750gl.39043/

Yep.

I’m more interested in a 7410 than a 750G - the reliance on Powerlogix software to set the second PLL is offputting - but both are worth creating interposers for.

In my testing, a 1GHz 750G is faster than a 600MHz 7410 for most things. The G4 chip has altivec but the main improvement is 3-4x faster memory thruput vs the G3. I have not seen if anyone has tested this specifically on the Beige or B&W machines. The large, fast, on-chip cache of the 750G seems to make up for the slow memory in most cases.

7410 chips are also a nice upgrade. That would be neat to see. What voltage would you run the external SRAM chips at? Or would you move them too?

I’d assume I’d have to run them at 2.5V with a 7410. Or is that not the case — can I run the 7410’s cache controller at 2.5V and the cache chips at 3.3V?

 

[LightBulbFun]

I’m more interested in a 7410 than a 750G - the reliance on Powerlogix software to set the second PLL is offputting

thats only needed because of how PowerLogix themselves setup their CPU cards with the first PLL at a slow speed, you could easily just set it to a higher speed on any 750GX based project you yourself design