On Sun, 20 Jul 2008 02:51:55 GMT, johnsuth@nospam.com.au wrote:
>
>The Adaptec 29160N card has a seemingly redundant key slot on the PCI bus comb.
>
>Adaptec literature is silent on the reason for this feature, but it may allow
>the card to plug into a PCI-X slot.
>
>Would this work and at what bus frequency?
It will work in any PCI slot, or any PCI-X Mode 1 slot, but it is limited to
32 bits x 33mhz, regardless. If you plug it into a PCI-X bus, it will force
the bus to operate at 33mhz.
"daytripper" <day_trippr@REMOVEyahoo.com> wrote in message
news:l5c584hlsut6dsqb25rink62215tp7v6br@4ax.com...
> On Sun, 20 Jul 2008 02:51:55 GMT, johnsuth@nospam.com.au wrote:
>>
>>The Adaptec 29160N card has a seemingly redundant key slot on the PCI bus comb.
>>
>>Adaptec literature is silent on the reason for this feature, but it may allow
>>the card to plug into a PCI-X slot.
>>
No, it's a standard PCI 2.1 feature (3.3/5V) for 66 Mhz.
>>Would this work and at what bus frequency?
>
> It will work in any PCI slot, or any PCI-X Mode 1 slot, but it is limited to
> 32 bits x 33mhz, regardless. If you plug it into a PCI-X bus, it will force
> the bus to operate at 33mhz.
No, all U160 cards are PCI 66Mhz. U320 is usually PCI-X.
Not entirely but above page would give you reason to think that that key
is indeed wrong (not redundant, just wrong) *if* you were to think that that
key is for PCI-X (or even 66MHz PCI):
> > but it may allow the card to plug into a PCI-X slot.
If that is what that key is for which I think it's not.
I believe it's just a 3.3V key which on a card merely means that it's not
limited to 5V signalling. As a consequence it can be used in PCI-X slots too.
The key may also be a clue to what (minimum) PCI specification the card
adheres to.
> >
> > Would this work and at what bus frequency?
> It will work in any PCI slot,
3.3V and 5V alike, since it has both 3.3 and 5 Volt keying.
> or any PCI-X Mode 1 slot,
Which apparenty uses 3.3V signalling _only_.
> but it is limited to 32 bits x 33mhz, regardless.
As is the specification for that card, (by omission?).
However, it's not the specification of the AIC7892 chip that it uses.
> If you plug it into a PCI-X bus, it will force the bus to operate at 33mhz.
As in 'PCI' mode.
However, since the chip is 66MHz capable (and also 64-bit capable, which
the card isn't, so maybe that can be configured off) it may run at 66MHz
too, unless that too can be configured off.
Adaptec 29160N 
Linear Mode
