On Thu, Jun 09, 2005 at 08:19:25PM +1000, Max Matveev wrote:

> When why is ChalS in IP22 class - it's the same board as Indy.

If the board sets bit 0 in IOC_SYSID, it is an IP24 ("Guiness").  If the bit
is not set, it is an IP22.

The Challenge S might use a chopped-down IP24 board -- if such were the
case, one would expect that bit to be set.  However, SGI design engineers have
been known to make interesting hardware design decisions.

(disclaimer: I've never seen the inside of a Challenge S, and I've never
seen the dmesg from a Challenge S)

The IP22/IP24 hardware docs make a distinction between IP22/IP24, there are
numerous minor register-level differences between the two, so we continue the
differentiation.

> Actually, IP24 and IP26 never have being used for product names, they
> were for internal use only.

That's nice.  Every hardware reference that I've seen, SGI or otherwise,
lists IP24 as a valid ID.  Google a bit for "SGI IP24", or read the IOC
documentation.

Your headers indicate that you work at/for SGI Australia.  For concrete reasons
why SGI decided to use IP24 as a designation for the Indy rather than IP22,
I suggest that you ask your counterparts in Mountain View.

-- Chris