On Wednesday 26 March 2003 07:44 am, Ray Phillips wrote:
> Dear port-alpha:
>
> Could someone explain about the two long (64-bit?) PCI slots in the
> PWS, please?  I mean what's special about them, and which type of
> cards should be plugged into them?  The only card I have which will
> work in them is the Q-Logic 1020 SCSI controller which came in my
> machine.

The Pyxis bug.  PCI DMA transfers that cross page boundaries are broken in the 
earlier Pyxis hardware, found on Miatas.  32-bit slots (the short ones) are 
fine to use as the PCI-PCI bridge breaks the transfer in a fortunate way.  
Devices in the 64-bit slots (long ones) won't work reliably without patchy 
code in the SRM, and the SRM refuses to let you boot with an unsupported card 
in those 64-bit slots.

You may override this check in the SRM with 'set pci_device_override 
<dev_id><vendor_id>', but expect data loss.

There's a great deal of info on this list, if you need more!

> Ray

--Dave