Re: Different Mac Models.

At 12:43 PM +0000 3/15/00, Iain Sandoe wrote:

quoted

quoted

To nitpick, the chip in question (the PMU) is really a power
management chip which also happens to implement ADB in older models.

The Sawtooth, iBook, and Pismo all use a new PMU design which is the
first major revision in many years.  It probably doesn't actually
have any pins dedicated to a physical ADB bus anymore, but a virtual
ADB bus implemented in the PMU's firmware is quite possible.

 Yes, that's how it's implemented: software emulation of ADB in the PMU.
 To my knowledge it's only in the firmware of the iBook and PowerBook PMU,
 not in the new iMac nor in the G4 PMU.

firmware as in local (to the PMU) flash/rom...

Firmware local to the PMU.  Previous to the new PMU, the firmware was
in mask ROM, but the new PMU used in Uni-N based systems has flash so
it can be updated.  In both cases the ROM / flash is integrated into
the PMU die, separate from the main system firmware ROM/flash.

   Tim Seufert

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