Fwd: Re: RE: Resolving ISA card IRQ interference with PCI INTA# to IRQ assignment

[Mike Jadon <mikej@umem.com>]

Austin-
 
I would think it is the task of the system BIOS to reserve the ISA card ISR. I don't know how to find out what ISR it has assigned to the ISA card. Second, it is my understanding that ISA cards use edge triggered interrupts, unlike PCI which uses level triggered interrupts, and consequently ISA IRQs are not sharable.
 
Mike
 
 

----- Original Message -----

From: "Austin Franklin" <darkroom@ix.netcom.com>
To: "Mike Jadon" <mikej@umem.com>
Subject: RE: Resolving ISA card IRQ interference with PCI INTA# to IRQ  assignment
Date: Wed, 17 Oct 2001 19:16:50 -0400
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Two things.  What about "reserving" the ISA IRQ in the motherboard BIOS?  Second, any is supposed to be written such that it allows IRQ sharing.
 
Regards,
 
Austin Franklin
austin@darkroom.com
 
 -----Original Message-----
From: Mike Jadon [mailto:mikej@umem.com]
Sent: Wednesday, October 17, 2001 6:40 PM
To: pci-sig@znyx.com
Subject: Resolving ISA card IRQ interference with PCI INTA# to IRQ assignment

We have a 64-bit/33MHz PCI card which uses INTA# and has no ROM BIOS extension (even though space has been provided for it) which prevents a PC from booting if it installed in a particular PCI slot, and an ISA is installed in a corresponding ISA slot. If either of these cards are moved to different slots on their respective busses the system will boot.

 

The theory is that the PCI card is getting assigned the same IRQ as the ISA card. Does anyone know of a BIOS mechanism which we could use in a ROM BIOS extension to ensure there are no IRQ conflicts between the ISA card(s) and our PCI card?

Mike Jadon

 

Mike Jadon

Micro Memory, Inc.

(US) Tel 818 998 0070 x 318

(US) Fax 818 998 4459

mikej@umem.com

www.umem.com

9540 Vassar

Chatsworth, Ca.

USA 91311

Mike Jadon
Micro Memory, Inc.
(US) Tel 818 998 0070 x 318
(US) Fax 818 998 4459
mikej@umem.com
www.umem.com
9540 Vassar
Chatsworth, Ca.
USA 91311

Mike Jadon
Micro Memory, Inc.
(US) Tel 818 998 0070 x 318
(US) Fax 818 998 4459
mikej@umem.com
www.umem.com
9540 Vassar
Chatsworth, Ca.
USA 91311