Emulators of Classic Computers

From: Tom Jennings <tomj_at_wps.com>
Date: Thu Jan 22 17:09:01 2004

On Tue, 2004-01-20 at 17:14, R. D. Davis wrote:
> Quothe ben franchuk, from writings of Tue, Jan 20, 2004 at 01:44:52PM -0700:
> > So are TUBE computers better?
>
> Theoretically, they could be faster than solid state computers.

Aww come on, tubes suck!

First off, a cloud of decidedly non-relativistic electrons has to travel
a SIGNIFICANT fraction of an inch. The elements are HUGE massive
capacitors (even nuvistors have at least a couple pF element to
element). Read about the Miller Effect. It's hard to make tubes run
(logic) at one motorcycle. The element areas are such that electrons
leave from different distances on their way to the plate that it causes
essentially multipath problems!

Plus, their physical size makes circuit-length a major problem.
Speed-of-light-in-metal is a limit speed factor in today's chips, and is
one of the things that Seymour figured out how to deal with in his Cray
machines. Even tubes consuming 1/100th the volume are still huge. Never
mind filaments. Filaments! Vff!

Tubes are fun, but they're not really any good for anything useful (and
I don't want to hear from any audio tube nuts :-)

tomj
Received on Thu Jan 22 2004 - 17:09:01 GMT