Firewire ExpressCard (Core Duo - 945) Problem

NTDEV
1

I’m looking for help/info on a firewire issue that is occuring on new
laptops with ExpressCard slots. The particular model that I have to
test on is a Dell M65 Core Duo (with 945PM chipset). This machine has
both a PCMCIA slot and an ExpressCard slot (but most other machines
only have the ExpressCard slot).

I’ve tested with 3 different 1394a express cards (SIIG, Belkin and
AboCom). In all cases I am unable to allocate isochronous resources
(channel and bandwidth). When I disable resource allocation then the
(isochronous) image transmission runs but suffers packet
loss leading to scrambled images. Asynchronous communication appears to
work fine but I have no option to transmit images from my camera that
way.

There is no problem when I attach the camera to a PCMCIA 1394a card
plugged into in the same computer using either the regular or the
gimped driver.

What is really strange about the packet loss is that if the computer
gets busy then the packet loss quits for the length of time that the
computer is busy. Ffor example, if I push the PCMCIA firewire card
into its slot while receiving images on the ExpressCard, then the
image transmission clears up until Device Manager updates its list at
which point the packet loss continues. It’s as if some other activity
that interferes with the ability of the ExpressCard to get data to
memory has been momentarily blocked.

Doing some searching on the Internet seems to indicate that there is
an issue with core duo processors and the 945 chipset which is
affecting Firewire and ExpressCard operation (running with /ONECPU
doesn’t help though).

If anyone else has experianced these issues or knows anything about
the processor/chipset issue or has any other thoughts on the matter I
would appreciate hearing what you know. I am currently also
communicating with Dell, Intel and someone who knows about problems
running firewire sound cards on these systems.

Likewise, if anyone has succeed with isochronous communication using
a 1394a ExpressCard I would also appreciate hearing from you.

Thanks,

Robert Newton
VX Technologies

2

Hi Robert, I’ve been working on 1394 quite a lot and should mention that I
have not seen much bus specific help on this list. I’ve had reports about
PCIe firewire card problems which I am about to look at. If I learn anything
I’ll let you know. Hopefully we can increase the 1394 awareness as I’m led
to believe that this is due to expand in popularity with a new generation of
1394b devices coming into use.

BTW is the Dell m65 on-board interface 1394a or b? The website and product
brochure don’t say. - Mike

----- Original Message -----
From: Robert Newton
To: Windows System Software Devs Interest List
Sent: Tuesday, October 31, 2006 9:24 PM
Subject: [ntdev] Firewire ExpressCard (Core Duo - 945) Problem

I’m looking for help/info on a firewire issue that is occuring on new
laptops with ExpressCard slots. The particular model that I have to
test on is a Dell M65 Core Duo (with 945PM chipset). This machine has
both a PCMCIA slot and an ExpressCard slot (but most other machines
only have the ExpressCard slot).

I’ve tested with 3 different 1394a express cards (SIIG, Belkin and
AboCom). In all cases I am unable to allocate isochronous resources
(channel and bandwidth). When I disable resource allocation then the
(isochronous) image transmission runs but suffers packet
loss leading to scrambled images. Asynchronous communication appears to
work fine but I have no option to transmit images from my camera that
way.

There is no problem when I attach the camera to a PCMCIA 1394a card
plugged into in the same computer using either the regular or the
gimped driver.

What is really strange about the packet loss is that if the computer
gets busy then the packet loss quits for the length of time that the
computer is busy. Ffor example, if I push the PCMCIA firewire card
into its slot while receiving images on the ExpressCard, then the
image transmission clears up until Device Manager updates its list at
which point the packet loss continues. It’s as if some other activity
that interferes with the ability of the ExpressCard to get data to
memory has been momentarily blocked.

Doing some searching on the Internet seems to indicate that there is
an issue with core duo processors and the 945 chipset which is
affecting Firewire and ExpressCard operation (running with /ONECPU
doesn’t help though).

If anyone else has experianced these issues or knows anything about
the processor/chipset issue or has any other thoughts on the matter I
would appreciate hearing what you know. I am currently also
communicating with Dell, Intel and someone who knows about problems
running firewire sound cards on these systems.

Likewise, if anyone has succeed with isochronous communication using
a 1394a ExpressCard I would also appreciate hearing from you.

Thanks,

Robert Newton
VX Technologies

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