2002-12-04

andrewducker: (Default)
2002-12-04 08:11 am

Why mainframes

I'm working with mainframes in my new jo, and people keep saying "Mainframes - those still exist???"

Here's why:

Each CPU die contains two complete execution pipelines that execute each instruction simultaneously. If the results of the two pipelines are not identical, the CPU state is regressed, and the instruction retried. If the retry again fails, the original CPU state is saved, and a spare CPU is activated and loaded with the saved state data. This CPU now resumes the work that was being performed by the failed chip.

article here.
andrewducker: (Default)
2002-12-04 03:33 pm

The teeth! The terrible teeth!

You've watched Buffy or played Vampire (or if not, you're my Mum. Nobody reads this list and doesn't fall into one of those categories). You've therefore always wondered - how many vamps can actually share a town with people.

And here, finally, is the answer. Worked out properly by someone far too smart who should have been working rather than calculating fictional population densities.