Confused about IRQ Settings

[rharbin]

I have had lots of trouble installing my internal PCI 56K USR modem. I just reformatted my HD and Win98SE will not recognize the modem that I've had working fine for a year. So I'm not positive it is an IRQ issue but I've done lots of reading about IRQs. I have a couple questions specific to my assignments (below is a list of what shows in my device manager). Note - before I reformatted, I had reset my cmos and it messed up some of my bios settings (two of which were to disable the on board sound card and modem).

My questions are:

1. Are there any IRQs available that I could try and assign my modem to? My cmos says the modem should be assigned to IRQ 3.
2. If I "remove" Com 1 and Com 2 in the device manager, will they auto reinstall when I reboot? I'm thinking IRQ 3 or 4 might be tied to the on board modem which i disabled in my bios.
3. IRQs 5, 10, and 11 list a "ACPI IRQ Holder for PCI IRQ Steering" device. What is that? Are these "reserved"?
4. Item 9 lists "SCI IRQ used by ACPI bus". What is this?


00 System Timer
01 Keyboard
02 Programmable interrupt controller
03 Communications Port (COM2)
04 Communications Port (COM1)
05 ACPI IRQ Holder for PCI IRQ Steering
05 Creative SB PCI 512
05 VIA Tech 3038 PCI to USB Universal Host Controller
05 VIA Tech 3038 PCI to USB Universal Host Controller
06 Floppy Disk Controller
07 Printer Port (LPT1)
08 System CMOS/Real time clock
09 SCI IRQ used by ACPI bus
10 ACPI IRQ Holder for PCI IRQ Steering
10 Rage Fury Pro/Xpert 2000 Pro (English)
11 ACPI IRQ Holder for PCI IRQ Steering
11 3Com HomeConnect(tm) 10M PCI Phoneline Adapter
12 Mouse
13 Numeric Data Processor
14 VIA Bus Master PCI IDE Controller
14 Primary IDE controller (dual fifo)
15 VIA Bus Master PCI IDE Controller
15 Secondary IDE Controller (dual fifo)

 

[DaveK]

You can try disabling one of the COM Ports in your BIOS to free up an IRQ.

DaveK

 

[DN]

What motherboard do you have..? In your BIOS settings, disable COM2 only.. Reboot.. You should no longer be using IRQ3 - check device manager to ensure this.. Turn off PC.. Install the modem.. Reboot.. See if the modem gets detected now.. Post results..

 

[bacillus]

<< 1. Are there any IRQs available that I could try and assign my modem to? My cmos says the modem should be assigned to IRQ 3. >>


at present all your irqs are being used.
first off, if you're not using your serial ports then I suggest you disable one or both in bios to free up 1 or 2 irqs & then try installing your modem. the modem does not have to use irq3!



<< IRQs 5, 10, and 11 list a "ACPI IRQ Holder for PCI IRQ Steering" device. What is that? Are these "reserved"? >>


that's normal windows behaviour when dealing with hardware.
Iwould also try moving your soundcard to another slot to try to stop it sharing with PCI to USB Universal Host Controller. this may or may not actually be a problem but I find that a soundcard works best if it's not sharing its irq with anything else.