Shared slots?

[mdriggs]

What exactly does it mean when two slots (a PCI and an ISA or a PCI and an AMR)are referred to as "shared"? Does it mean that only one of the two can be used, that they share interrupts, or what?

Thanks.

--MR

 

[Heretik]

It means that they share the same IRQ channel. Most modern cards supposedly support IRQ sharing but some (especially network & video cards) seem to still have problems sharing resources.....

 

[mdriggs]

Thanks much.

--MR

 

[SaturnX]

Aside from sharing IRQs if you have a shard PCI/ISA slot then only one of the two can be used at a time. My board has that (Intel SE440BX-2), but it all depends on the board design. Most slots which share with AMR/CNR/ISA slots mean that only one of two can be used.

--Mark

 

[mdriggs]

Thanks. That's what I'm concerned about.

--MR

 

[mastertech01]

I just make sure Buss mastered devices like SCSI controllers etc arent sharing with other Buss mastered devices.

 

[mdriggs]

No bus-mastering devices. I just would like to be able to stick a modem into the AMR slot (as a backup for when the DSL is down) and still be able to put something like an audio or FireWire card in the shared PCI slot. And have each of them work when I need it. Is that a realistic goal, or am I whistling in the wind?

Thanks.

--MR

 

[Peter]

Two kinds of sharing here:

PCI slots sharing an interrupt. This is not a problem, not even with bus mastering devices - as long as their respective driver software is written to follow the PCI specification. One might think PCI has been here for long enough (seven years), but there are still some poorly written drivers out there.

The other one is mechanical sharing - that means that two slots of different kinds (PCI and ISA, ISA and AMR, ...) share a slot bracket position, meaning you can only fit one card at a time. Like when you have an ATX board (thus allowing seven slot positions total) with 1 AGP, 5 PCI and 2 ISA, then you'll have one position where you can either fit your fifth PCI card or your 2nd ISA card.

Regards, Peter

 

[mdriggs]

Thanks.

--MR