New LC475 user - Questions on PowerPC upgrades

[phipli]

I wonder if this would work in an LC III, it is the same computer save for the CPU

Hum, I think you're getting muddled there - the LC 475 is very different to the LC III. The LC and LC II were very similar to each other, but the LC 475 has more in common with the Quadra 610, 650 and 800. Even then the chipset isn't that similar... just related.

The LC III has much lower (what is it, 36MB by default?) RAM limits, but there are some hardware modifications that can get you higher than that, but not easily, and not 136MB.

 

[Trash80toG4]

The LC475 and Q605 are twins, there's a jumper you can change to fake up one in the other's case, all the same Quadra bits inside.

Developer Notes for Macs have Block Diagrams to compare components/architectures. Q605 was handy:

 

[Trash80toG4]

Yep, they're wildly different under the hood, entirely different architectures. I'll see if I can drop an LCIII Block Diagram in for comparison to the Q605/LC475.