AGP, PCI Slots and IRQ Sharing

Frequently asked questions about the BP6.

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hyperspace
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AGP, PCI Slots and IRQ Sharing

Post by hyperspace »

How does the BP6 share its IRQ's?

The BP6 PCI slots are numbered 1-5 starting with the PCI slot closest to the AGP slot. ISA1 is next to PCI5 and ISA2 is next to the edge of the mainboard. Many problems experienced with the BP6 are due to not understanding how IRQ's are shared between the AGP, PCI and ISA slots. Knowing the IRQ shares will help with your PCI card placement. Many BP6ers have all PCI slots filled.

AGP and PCI1 share an IRQ.

PCI2 does not share its IRQ.

PCI3 and the HPT366 share an IRQ.

Here's what the BP6 manual says:

PCI slot 3 shares IRQ signals with the HPT366 IDE controller (Ultra ATA66). The driver for HPT366 IDE controller supports IRQ sharing with other PCI devices. But if you install a PCI card that doesn't allow IRQ sharing with other devices into PCI slot 3, you may encounter some problems. Futher, if your Operating System doesn't allow peripheral devices to share IRQ signals with each other -- Windows NT for example, you can't install a PCI card into PCI slot 3.

PCI4 and PCI5 share an IRQ. They also share the same bus mastering signal.

Here's what the BP6 manual says:

PCI slots 4 and 5 use the same bus mastering control signal, therefore, you can't install two PCI cards that will occupy the bus master signal into both PCI slots 4 and 5 at the same time. What kind of PCI cards needs to use the bus master signal? Generally speaking, most of the PCI cards need to use the bus master signal but some Add-on cards such as the Voodoo series of graphics cards and some PCI-VGA and LAN cards don't occupy the bus master signal.
jwelch
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MB lockup on boot w/wireless G

Post by jwelch »

The comnputer does not boot @ all when I put the Linksys 2.4 GHz WMP54G in any pci slot. I pulled every card except the video card and still no go. Any suggestions? Thank you!
hyperspace
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Re: MB lockup on boot w/wireless G

Post by hyperspace »

jwelch wrote:The comnputer does not boot @ all when I put the Linksys 2.4 GHz WMP54G in any pci slot. I pulled every card except the video card and still no go. Any suggestions? Thank you!
Is ACPI enabled in the BIOS? If yes, disable and see what happens.
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Post by energy »

I put a MSI PC11B2 card (WiFi 802.11b) on a my BP6 motherboard but my PC doesn't boot : there's no message at all !
I tried to disable ACPI, I tested all PCI slot and I also tried to disable any controller I can (IDE, FD ...) but the result is always the same : black screen !!!

Please help, thanks, David.
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