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Question -- I'm getting ready to add a second, fully-populated 527 board to a C4PMF to achieve 48K. Does anyone know if the two PSU's that came installed with the original C4PMF's provide sufficient current to power all that RAM?

What are the specs on the transformers?
What are the pass elements in the regulators?
How much current does a fully populated 527 board draw?

We should be able to figure this out.

I get the specs on the transformers. One of them is definitely committed to just the 527 board and the other one supplies the backplane -- and through the backplane both the 505 and 540 boards.

A 2114L draws a max of 100ma. With 48 2114's on a fully populated 527 board, the theoretical max current could be something like 4.8A?!

Call it 5 amps to account for any other logic on the board.

I'd say, in order to keep things reasonably cool you would need 7 amps reserve on that power supply to add another 527 board.

Originally my C4PMF had two 5 amp power supplies to power the two 527 boards in the system. One 5 amp for the CPU and the first 527, and another 5 amp for the second 527 and the view board. HOWEVER, I replaced the original power supplies with a new, 10 amp regulated switching one that is tremendously more reliable, and cooler. It was not expensive.

Here is a photo: /Jeff