[rescue] Help the ailing Frankenmac
mrbill at mrbill.net
Mon May 12 09:21:02 CDT 2008
On Mon, May 12, 2008 at 08:32:56AM -0400, William Enestvedt wrote:
> I thought the CUDA button only cleared the power management settings.
"The Power Management Unit (PMU) on the Power Macintosh G3 computers, Power
Mac G4 (PCI) and Power Mac G4 Cube is known as the "Cuda button". In the
later models It is identical in function and appearance to the PMU.
Resetting the Cuda or PMU also resets date and time settings. After the
reset, on some Power Macs, the system clock is set to 00:00, 01 Jan 1904
for computers with Mac OS 9 or 00:00 (GMT), 01 Jan 1970 for computers with
Mac OS X.
The PMU is a microcontroller chip that controls power functions for the
computer. The PMU is a computer within a computer, as it has its own
memory, software, firmware, input/output, a CPU, and more. Its function is
* Tell the computer to turn on, turn off, sleep, wake, idle, etc.
* Manage system resets from various commands.
* Maintain parameter RAM (PRAM).
* Manage the real-time clock.
Over time, the settings in the Power Manager may become unusable, which can
result in operational anomalies with the computer. Examples include not
turning on, not waking from sleep, or not seeing devices plugged into the
USB and FireWire ports, among others."
More information about the rescue