SGI: Hardware

Does anyone know where on a single-CPU module for Octane resides the NIC chip?
It's this which reports back the info given by hinv -vm for serial no. and part no.

I have a CPU which works 100% ok (ide diags, every benchmark, etc.), but it halts
on power-up because the serial number NIC on the module is bad. If I can locate
the NIC, perhaps I can swap it for a NIC from a lesser CPU. It'll report a different
SN/PN of course, but at least it will then boot and function ok. Anyone know? Is it
perhaps the DS2505 IC?

Ian.

Solved!!

There is a surface-mount 6-pin IC inside the module on the PCB, marked DS2505. This is the NIC. I swapped
it for the same IC found in an old R10K/175; bingo! No more halt at power-on, PROM hinv is fine, CPU working
as normal (performance checks with c-ray, etc.), IRIX hinv is fine. Only the PROM command 'system' and IRIX
'hinv -vm' show a different PN, and a serial that doesn't match the sticker on the CPU.

Makes a chance... fixing a PITA problem in just a couple of hours.

Ian.

Just so that future generations can find this more easily: the NIC discussed here is the "number in a can" eprom(?) which is used in e.g. Octane and O2 to store the serial number, not the network interface...

Indeed, good point! And yes it's an EPROM.

For anyone reading this in the future, note that the part used in O2 looks completely different; located on
the PCI tray PCB, it looks just like an ordinary transistor, has only 3 pins and is not surface-mount.
Thus, if you want to change an R5K O2 to R10K (or vice versa), then swap over this component
between the two PCI trays and this will retain the serial no. to match the sticker on the back of the O2.

Ian.

The DS2505 is available in TO-92 ('transistor') and TSOC (surface mounted) packaging. The datasheet is available here .

I've edited my post so it makes more sense.

Ian.