Homebuilt TTL and transistor CPUs

[Peter C. Wallace]

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