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Cadaver · Sep 25, 2003, 08:23 PM

I'm looking at the Apple System Profiler, and apparently the G5 has 5 USB buses.

Here's what I can figure out:

USB 0 = top rear port, ADC's USB and front port (verified)
USB 1 = ?
USB 2 = ?
USB 3 = ?
USB 4 = bottom rear port (verified)

Now, I presume that one of the three mystery ports is for the modem (which I believe is USB-based in the G5). I also presume that another is actually the internal Bluetooth connector.

So, that still leaves one port for what function I have no idea.

Can anyone shed some light on this?

ZackS · Sep 25, 2003, 08:37 PM

The last one is probably the USB for the ADC card connection.

Hydra · 08:57 PM

Originally posted by ZackS:
The last one is probably the USB for the ADC card connection.

Yes the 4th is for BT. But according to the system profiler all the other USB ports go through USB 0 (the back ports, the front port and the ADC port on the Display).

-Jerry C.

Cadaver · Sep 25, 2003, 09:15 PM

Originally posted by ZackS:
The last one is probably the USB for the ADC card connection.

Not quite right.

I'm playing with the machine right now:

-Bus USB 0 connects to the G5's top rear USB port, both ADC ports, and the G5's front port.
-Bus USB 4 connects to the G5's bottom rear port.

So, Bus 0 has 4 connectors (one rear, one front and 2 on an ADC monitor). Bus 4 has one connector (one rear).

That leaves 3. One I guess is for the internal BT, and one for the internal modem. So, what's the unaccounted-for-one do??

Hydra · Sep 25, 2003, 09:24 PM

Originally posted by Cadaver:
Not quite right.

Not on my dual G5. The mystery deepens. I have USB devices plugged in all ports right now (only one port on the KB is left open). I am staring at ASP right now and it shows everything (both rear, the front port, the ADC hub and keyboard) all coming off of USB Bus 0. USB Bus 4 is the only exception and it shows it as occupied by Bluetooth HCI (I have built in BT). 1,2 and 3 empty. Could this be some mysterious motherboard revision?

-Jerry C.

tooki · Sep 25, 2003, 10:30 PM

It has to do with USB 2 -- the same physical ports can be routed to any of 3 actual USB controllers (2 OHCI [USB 1.1] controllers, 1 EHCI [USB 2] controller) as needed. These three are all inside the USB controller that's off of the PCI bus.

The other two are the two controllers that are in the I/O controller, used for the internal modem and bluetooth.

tooki

Cadaver · Sep 26, 2003, 09:37 PM

Originally posted by tooki:
It has to do with USB 2 -- the same physical ports can be routed to any of 3 actual USB controllers (2 OHCI [USB 1.1] controllers, 1 EHCI [USB 2] controller) as needed. These three are all inside the USB controller that's off of the PCI bus.

The other two are the two controllers that are in the I/O controller, used for the internal modem and bluetooth.

tooki

Ah ha! Thanks.

Hydra · Sep 26, 2003, 10:26 PM

Thanks, that clears that one up.

-Jerry C.