Homebuilt TTL and transistor CPUs

Peter C. Wallace pcw at mesanet.com
Thu Jan 5 09:17:25 CST 2006

On Wed, 4 Jan 2006, Chuck Guzis wrote:

> On 1/4/2006 at 8:14 PM Peter C. Wallace wrote:
>> Neon bulb logic?
> Kind of neat in that the logic state is visible.  Hard to use for anything
> more than simple circuits--aging and uniformity are real problems.  I built
> a couple of ring counters using them though.
> Why not Shockley diodes?  Anyone remember the Shockley demo of a diode-only
> audio amplifier back in the 60's?

Isnt that just a four layer diode? voltage mode negative resistance?

Just build it in GaP and you'll have a solid state 'Neon' :-)

>> Tunnel Diode logic?
> Still got about a dozen of those things in my hellbox.

Hard to beat if you need a really fast (but low amplitude) edge

> Cheers,
> Chuck

Peter Wallace
Mesa Electronics

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