Jeffrey Engle wrote:
> 
> On Oct 23, 2009, at 9:58 AM, Jason Brown wrote:
> 
>>
>> On Oct 23, 2009, at 11:11 AM, Jeffrey Engle wrote:
>>
>>> Funny thing... I have an early 2005 Powermac G5 with "3 USB ports" on
>>> the tower itself. Two on the rear and one on the front. Why does
>>> system profiler say that I have 4 "USB Bus" and 1 "USB High-speed
>>> Bus"? equalling 5 usb busses all together? and I thought ALL of the 3
>>> that I do have were "High-Speed" Can someone explain?  Thanks, Jeff

>> Your tower has 3 usb ports. Your keyboard has 2 non powered ports on
>> them. The other part of the question, the USB high speed bus. The best
>> that I can figure is that it is driven by another driver in the system
>> or is a physically different chip. Someone else that is more
>> knowledgeable may be able to answer that part.
>>
>> Jason Brown
>>
> 
> Jason, please keep in mind that system profiler only "sees" those USB  
> ports available to it. Thus, if the keyboard is NOT plugged in, you  
> will not see those ports. So, back to the drawing table. Jeff

The ports on the keyboard are just that, ports, not busses.  They are on 
the same bus as the port the keyboard is plugged into.

The way the system reports busses is strange.  I don't know why it does 
what it does but it does change the reporting of high speed busses 
depending on what you have plugged in.  It seems to overlap the "high 
speed" and low speed busses.  That is it reports 4 low and 1 high but 
that high is really the same as one of the low speed.  I tried to figure 
it out once on my iBook and just found more confusion.

There is a USB diagnostic tool, part of XCode, that is more detailed and 
technical but less confusing once you get past the details.  IIRC when I 
looked with that it was clear, but it's been a while since I did that 
and I can't recall the specifics.

I think in the OP's case there are 4 busses, one for each of the three 
ports and one additional port, either a connector on the motherboard and 
or used by hardware built into the motherboard such as BlueTooth.  Even 
if the machine doesn't have BT there may be some support for it on the MB.

For example, this MacBook Pro.  ASP shows 5 "USB Bus" (lo) and 2 "USB 
High-Speed Bus" (hi).  Now 2 lo and one hi are used internally for BT, 
keyboard / trackpad, IR receiver and iSight.  Leaving 3 lo and 1 hi not 
tasked and two external ports on the MBP.

If I plug in a USB 2.0 card reader it appears on the previously untasked 
hi bus.  If I switch it over to the other port it now appears on the 
same bus as the iSight.  With a mouse plugged in to the first port, it 
shows up on the same lo bus with the BT controller.  That is it is 
plugged into the same connector that the card reader was plugged into 
and appearing on a hi bus.

I guess the one hard piece of data is that the ASP list is screwy.


-- 
Clark Martin
Redwood City, CA, USA
Macintosh / Internet Consulting

"I'm a designated driver on the Information Super Highway"

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are a member of G-Group, a group for 
those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs.
The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette 
guide is at http://www.lowendmac.com/lists/netiquette.shtml
To post to this group, send email to [email protected]
For more options, visit this group at http://groups.google.com/group/g3-5-list
-~----------~----~----~----~------~----~------~--~---

Reply via email to