[geeks] Home made SGI O2 CPU upgrade

[Rob Fielding]

> It won't work in an Octane, nor would we want to do it to an Octane.
> You do that to an Octane and you turn the Octane from a 64bit machine to
> a 32bit machine.

Yes of course. I didn't mean to suggest the mod as intended would be fit 
for the Octane, but the idea of home made CPU hackery is certainly 
appealing.

> R5000 chip used in lesser O2s and the Indy are not pin compatible and
> they are from NEC (to my recall).  

They are supplied by NEC and probably not pin compatible - does anyone 
know for sure? Whilst you are probably right about the arch speed, it 
would probably still be nice to have more MHz and a larger cache in the 
old Indy, and as they are virtually throw away machines now (I have one 
in throw-a-way condition) if I knew more, I'd probably have a go. I may 
just stick to an upgraded clock crystal and boost myself to 200MHz.
.
> Perhaps if someone in a country that legally allowed it would disasseble
> the machine code and post a summary of what it does, someone could write
> a knock off?

For the small scale not-for-profit hobby you'd probably get away with 
it. If someone wanted to start trying to make something out of it, which 
is completely out of order, then the cease and desist letters would 
surely start.

Cheers,

Rob