So, y'all got 4 RAM slots, eh? With PC133 RAM, I'm guessing it's a PM G4 Gig-E machine....?
I'll photo what I found soon.
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Edit =
OK, here's what I found in 512MB's.....
A pair of mismatched PC2700 333MHz sticks.
They're from upgrading MDD's to 1GB sticks.
IIRC, if, and that's a Big "IF", they're downclock compatible, they'll only be seen as 256MB sticks in earlier G4 PM's.
I *think* if they were correct form and function, a downgrade to G4 Quicksilver G4's was a possibility; not sure about going lower.
Do some homework, and LMK...., plus OWC has these for only $8 each anyway.....,
though I still have that 256GB SSD game console pull that I haven't done anything with.

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