On the MDD G4 logic board, next to the PMU Reset button, there are 4 unpopulated button pads:
S2 (no label)
S3 is marked "NMI"
S4 is marked "RESET" and
S5 is marked "POWER"
Im assuming S5 (POWER) simply duplicates the power button on the front of the case. S4 im guessing S4 (RESET) resets the machine? Yes? What i don't know is what the heck is "NMI"? Any ideas?
Non-Maskable Interrupt?
Whats it do?
...as seen on previous Mac models
http://en.wikipedia.org/wiki/Non-maskable_interrupt
...possibly.
Under OS X it might not do anything. Is your MDD one of the ones capable of booting OS 9? Under OS 9 it should display a prompt.
Mine can run OS 9, if i could be bothered to install it. Thanks for the info guys.