[geeks] Fun compariosn between Mac Plus and AMD Dual Core PC

[Sridhar Ayengar]

Jonathan C. Patschke wrote:
> On Fri, 20 Jul 2007, Sridhar Ayengar wrote:
> 
>>> OOPs, sorry to dispoint you it's a PCI, that must make it a 7200.
>> It's probably a bigger model than even that.  If memory serves, the 7200
>> had its 90MHz processor soldered in.
> 
> The 7200 does have a fixed processor.  However, Apple sold the 7200 in
> 75MHz, 90MHz, and 120MHz variants.
> 
> There's a very perverse processor upgrade module for the 7200 that lives
> on a PCI card.  The original processor boots Mac OS, and an INIT
> identifies the add-in card, gets the main CPU's caches into a known
> state, and then "pivots" the running system over to the faster
> processor.

Wow.  That's pretty strange.

The only card-based processor upgrades I've ever used are MCA cards that 
just take over the bus.

Peace...  Sridhar