>>Entirely different Apple custom chipset.
>
>If I may believe this source (c't magazine), it is a VLSI 9933, if
>anyone can find the pdf's, please mail me the URL. =)

I may be wrong, but I beleive VLSI is the founder used by Apple for ASIC
production.

>The Ethernet controller is an Intel 21143-TD.

Some Sawtooth G4s use the gmac inside Uni-N, others use the 21143.

>Seems that the G4/450 uses a Lucent FW803 06 for the Firewire.

You may be right for the lucent. Actually, those controllers
(Ethernet/FW) are subject to change quite quickly since ultimately,
they'll be integrated into Uni-N. Recent Sawtooth G4s now use the gmac
ethernet inside Uni-N instead of the external PCI-based lucent chip, and
Apple will certainly use the FW controller inside Uni-N too when it's ready.
Note that Apple developer notes is wrong when it writes about dbdma in
Uni-N. The gmac chipset used the classical ring-descriptor mecanism. The
Apple-like dbdma is in KeyLargo ans is not needed for ethernet. We have a
partially working gmac driver in linux now (we still lack the format of
the multicast hash tables).
The PHY apple uses with gmac is a BCM 5201 (Broadcom)

>The PCI-to-PCI bridge is an Intel 21154-BC.

As usual. This one should be transparent.

>A Lucent 1258AK3 for the KeyLargo, the 2nd ASIC, which does the
>communication between the IO controllers.

KeyLargo is yet another child of Grand Central with a dbdma controller
and a bunch of devices. It's an Apple ASIC which contains:

 - An OpenPIC (actually IBM MPIC2) interrupt controller
 - The VIA interface to the PMU (the good old VIA)
 - GPIOs (not that the PMU interrupt is no longer VIA CB_1 but is one of
the GPIO, you can look at linux/ppc source code for more details).
 - 1 Ultra/ATA channel (ata-4 node) and 2 old-flavor IDE controllers
(ata-3 nodes). The old-flavor controllers can also be used in some kind
of "pcmcia" mode which is used for the wireless card
 - 2 OHCI USB controllers (Hum... I think they are inside KeyLargo. But
they appear as different devices on PCI).
 - the good old Zilog ESCC connected to the modem. To get the modem
working on those machines, you need to tweak a few feature control bits
(again, see the linux source code for more details) and then use the SCC
channel A.
 - Some timers (I don't know about these, Apparently Apple didn't use the
OpenPIC timer)
 - A Davbus/I2S sound bus (used as I2S on iBook and davbus on G4, I don't
know for iMacDV)
 - Did I forgot something ?

>The modem is based on a Rockwell chipset.

Yep, but you don't need to care, it works with AT commands on the serial
port.