"Quadibloc" wrote in message
...

On Feb 1, 8:35 pm, "Lord Androcles, Zeroth Earl of Medway"
wrote:

Asimov's "positronic brain" for his robots was an unnecessary fantasy
for an artificially intelligent computer,

Yes, that's true.

And Star Trek filed the serial numbers off, and had "duotronic"
computers.

But, ironically, although there is no reason to think that computers
would work faster using positrons to carry information, integrated
circuits _did_ use _holes_ instead of electrons to carry information.

This had the benefit, in PMOS circuits, that gates could be more
tightly packed - although they were slower than the ones in NMOS
circuits which used electrons. So pocket calculators, which could be
slow, but had to be complex, were made from PMOS chips back in the
'seventies.

Today, though, CMOS circuitry, which, unlike either NMOS or PMOS
circuitry, doesn't require current to flow through it (except for
unavoidable leakage) when in a stable state, only when switching, is
used in the most advanced microelectronics as the lower power
consumption allows circuits to be made at a smaller feature size,
which would be far too hot if made from NMOS (even though that would
allow them to run faster, if they could be made to run, in fact they
would be too hot to run at all).

So, if "positronics" could refer to holes as positive charge carriers,
then in real life "duotronics" of a sort _has_ won out.

John Savard
==================================================
Holes are essentially no different to +ve ions in a battery moving to the
negative terminal while -ve ions move to the positive terminal. Why does
conventional current flow the wrong
way (negative to positive) inside Volta's pile when it's positive to
negative outside, and why was the convention based on hole flow? And how do
you make people unlearn convention?
The answer is: You don't! Instead, you teach the next generation the new
paradigm and leave the old fools to carry on insisting they are right and
making even bigger fools of themselves.

He who knows not and knows not that he knows not, he is a fool. Shun him.
He who knows not and knows that he knows not, he is a student. Teach him.
He who knows and knows not that he knows, he is a tool. Use him.
He who knows and knows that he knows, he is a sage. Follow him.

Bill Owen is a tool. You are a fool.

-- This message is brought to you from the keyboard of
Lord Androcles, Zeroth Earl of Medway.
When I get my O.B.E. I'll be an earlobe.