Is IRQ 9 bad for sound cards?

[LeoIX]

I've heard that IRQ 9 may be secretly shared by IRQ 2. Does anyone know if this is true? I have a Delta 66 and right now device manager indicates that it is alone on IRQ 9. I'm running Win98SE and am having problems with Cakewalk hanging.

System Specs FYI:
P4 2.4GHz CPU
512 MB DDR 2100
ATI Radeon 9000 Pro AGP (with dual monitors)
MSI 645 E MAX MB(SiS 645DX chipset)
Delta 66/Omni
Midiman 2x2 USB MIDI
Win 98SE
Dual WD 40 gig HDs

[GZsound]

Usually Windows will automatically assign IRQ's and you should not disable that function. The IRQ routing may or may not be the issue with Cakewalk. There are numerous tweaks required to make Cakewalk work properly and they seem to be different for each computer. I could never get Cakewalk (Pro 9) to work on my computer no matter what I tried so I threw it away.

I would suggest the Cakewalk support site.

[Roly]

Sound card alone on 9 is a good thing
IRQs don't share each other pci slots sometimes share IRQs.
Find out if your vid card is sharing an IRQ with anything else.
What else is in your rig?
What motherboard?

[This message has been edited by Roly (edited 12-19-2002).]

[MisterX]

No IRQ 9 is not shared.
Its redirected.
To understand the difference a detailed explanation is in order.
The interrupt mechanism present on PC's is controlled by a programmable interrupt controller (PIC). The chip used on early XT machines was a 8259A device capable of handling 8 hardware interrupts.
To be able to use more hardware in combination with the computer, a second cascaded interrupt controller was added to AT systems. To make this work, the secondary controller uses one interrupt line from the first controller. In an AT machine, IRQ line 2 is used by the system to signal the second chip.
This means that in the AT configuration, only 7 interrupt lines on the first controller can be used and 8 on the second. This makes a total of 15 possible hardware interrupts. To remain compatible with older applications, the hardware line of IRQ 2 on AT systems was redirected to IRQ 9 on the second controller. The system BIOS then redirects a hardware interrupt on line 9 to the virtual handler of IRQ 2. In this way, the interrupt service routine present for IRQ 2 is called, even if the occurring interrupt is the IRQ 9.
So in other words. IRQ 2 is used by the system and can't be allocated other devices. When an application queries IRQ 2 that query gets redirected to IRQ 9 by the BIOS. And this make the application happy.
Does that clear it up?
On most modern systems IRQ 9 is used buy the ACPI controller. Windows 98Se buy default does not install the ACPI configuration it installs the APM configuration. To install an ACPI configuration you use the /p /j command line options when your run the Windows installer. Changing to an ACPI configuration can solve many problems give it a try. IRQ sharing and PCI steering will work the way they are supposed to in a modern system. http://www.audioforums.com/forums/smile.gif
If your card using IRQ 9 bothers you at all. Change the IRQ...
First try moving the card to another slot. Consult your motherboard's manual to see how it routes IRQ's.
Second disable the onboard Com Ports.
If you are not using them you don't need them simple as that.Give them back to the system. The system board should automagicly reallocate the now unused IRQ's. http://www.audioforums.com/forums/wink.gif


Roly....take a look at the first post. The author clearly listed his system components. http://www.audioforums.com/forums/wink.gif

[Pretty Pretty Cyanide]

Only change your soundcard from IRQ9 if other items are also using IRQ 9. Disable ACPI, Do not use it. Reset your soundcard settings by shutting down the computer, moving the card to a different slot (but never beside an AGP port) and reset the nvram (or similiar settings) in the BIOS.

I have used 98se with a 667Mhz computer for awhile now (and with 2 or 3 exceptions due to me chaning things) there has been nothing wrong with my DAW. And didn't have to worry about that aspect like so many others.

[+Erik.+]

Originally posted by Pretty Pretty Cyanide:
[B]Only change your soundcard from IRQ9 if other items are also using IRQ 9. Disable ACPI, Do not use it. Reset your soundcard settings by shutting down the computer, moving the card to a different slot (but never beside an AGP port) and reset the nvram (or similiar settings) in the BIOS.

B]


you only need to disable APCI if you don't have an APIC option in your bios. Ensure this is enabled. This forces all the devices onto their own IRQ and is a feature of motherboards for nearly two years now. As your system is not as old as the above guys 667mhz it's probably got APIC.

APCI disabling is not as important as it once was. My DAW runs just fine with the APIC mode set in the bios and APCI running in XP.

[Pretty Pretty Cyanide]

Originally posted by +Erik.+:

you only need to disable APCI if you don't have an APIC option in your bios. Ensure this is enabled. This forces all the devices onto their own IRQ and is a feature of motherboards for nearly two years now. As your system is not as old as the above guys 667mhz it's probably got APIC.

APCI disabling is not as important as it once was. My DAW runs just fine with the APIC mode set in the bios and APCI running in XP.

He has a P4 2.4Ghz. I am the one with a 667Mhz. I am just stating what has worked for me. That's all.

[+Erik.+]

well you said "disable acpi, do not use it", so i just wanted to add that this is not a mandatory step anymore, but for your case i believe it is http://www.audioforums.com/forums/smile.gif of course, i suppose you meant only if the irq 9 was being shared. if the apic mode was disabled, enabling it would force the devices onto seperate irqs.

[This message has been edited by +Erik.+ (edited 12-18-2002).]

[This message has been edited by +Erik.+ (edited 12-18-2002).]