Hello List:
Although the questions are prompted specifically by my experience with my G4 AGP 450 Sawtooth model, a broader understanding of the CUDA would be interesting information.
What do Macs do differently when the CUDA is depressed for over 15 seconds vs. depressed for a couple of seconds?
Will the CUDA switch effects when depressed a few seconds vs. over 15 seconds vary from model to model?
Rephrased, are the G3 trayloader Imac CUDA effects vs G4 sawtooth CUDA effects vs other Mac models the same?
G4 Experience alluded to: Apparently there is a difference based on the experience I posted under Tiger on AGP 450:
Holding the CUDA switch for over 15 seconds, I was able to install Tiger.
When I had depressed the CUDA switch for only a couple of seconds, Tiger would not install for me on several attempts, however.
Thank you.
David Johansson
http://docs.info.apple.com/article.html?artnum=86760
The CUDA is powered by the PRAM battery if mains power isn't connected (which is supposed to removed when resetting the CUDA/PMU) so if the PRAM is bad/low/flaky then a CUDA/PMU reset may not happen as it should.
Mac PRAM, NVRAM, CUDA/PMU & Battery Tutorial
http://www.geocities.com/texas_macman/pram.html
Cheers, Tom
Thank you Texas Mac Man! The linked info is Wonderful!
After scanning the linked info, the issue of cleaning a possibly dirty CUDA switch arose.
Can spray on contact cleaner be used effectively to clean the switch?
(Easier to verify the apparent "obvious" solution than to discover the normal operating procedure does not apply the hard way in this particular case!)
Thank you again for the link, Tom!
David