.. said:
On Thu, 03 Apr 2008 23:11:20 -0400, Paul wrote:
There must be difference, otherwise why wouldn't the motherboard
recognize my PCI cards? The cards are both good. I can put them into
another PC and they are recognized.
PCI is a shared bus. The Address/Data lines go past all the PCI devices
in parallel.
The PCI spec would normally be purchased from pcisig.com . But if you
have a look with your search engine, you can find a copy of pci22.pdf
for download. About 3,835,430 bytes or so.
If you want a sample motherboard schematic, there is one at Intel.
PDF page 44 is where the PCI slots start. IDSEL gets wired to a different
AD bcon on each slot, for configuration cycles, but many of the other
signals are shared by all slots. The interrupt lines are "swizzled" but
that isn't important either to this discussion. All you need, is for
some interrupt line to be wired up, the exact line is not important
because they can be shared.
http://www.intel.com/design/chipsets/schematics/252812.htm
Something like a PCI slot clock could be disabled, and that
might be a reason for a slot to be disabled. But then the
question would be, why would that happen ? The BIOS has the
option of reaching into the clockgen, and disabling individual
clocks (it can be done to reduce EMI for example), but I don't see
why that would happen.
The clock generator on my motherboard, is this one. The register
to disable PCI clocks is on page 9, at the top of the page.
http://web.archive.org/web/20050530125355/http://www.icst.com/pdf/ics952607.pdf
And looking at the BIOS, I don't see something in particular
that would disable a portion of the PCI bus. There is an
"Onboard PCI Device" section to the BIOS, and the very last
item "OnBoard 1394 Controller" could be a PCI bus device. I
suspect the rest might be PCI Express devices. Do you have
the 1394 device disabled or enabled in the BIOS ?
I'm assuming here, that the 1394 device is an actual PCI bus
device, and seeing it visible in Windows is my proof that
*some* PCI device works. I would boot Ubuntu or Knoppix CD for
a second opinion, and try "lspci" and see what shows up there.
Paul