[Coco] Demo Meeting

johnmarkmelanie at gmail.com johnmarkmelanie at gmail.com
Sun Aug 7 23:55:05 EDT 2022


All,

On the third Thursday of the Month at 6:30 PM to 7:30 PM Chicago Time
Glenside Color Computer Club, Inc. is having a demo meeting.
If you would like to demo something during this time, then let me know.
I plan to give a talk on Nanoscale vacuum-channel transistors.
I like this transistor because it is very fast and will allow us to emulate
the CoCo at a higher clock rate.
NASA likes this transistor because it can operate at 500 degrees C and in
radioactive environments.

https://en.wikipedia.org/wiki/Nanoscale_vacuum-channel_transistor

A vacuum-channel transistor works like a vacuum tube, but it has no heater.
Also, there is no warm up time required.

It works like an n-channel JFET.

If you have 0 volts on the gate in reference to the source, then the
transistor is on.
If you have negative volts on the gate in reference to the source, then the
transistor is being turned off. The more negative the more off.

N-channel JFET logic gates:
https://www.techbriefs.com/component/content/article/ntb/tech-briefs/semicon
ductors-and-ics/3415

Vacuum tube logic gates:
https://hackaday.io/project/169147-low-voltage-vacuum-tube-logic-gates

Look at the pictures in this article:
https://technology.nasa.gov/patent/TOP2-174

The emitter, source, and cathode are the same.
The gate and grid are the same.
The collector, drain, anode, and plate are the same.

Notice that the emitter, source, cathode is pointy and not heated.
Apparently, electrons are more likely to travel off a point.

If both the emitter, source and collector, drain are pointy then the then
the source and drain are interchangeable. 

Making the source pointy and the drain flat may make the device work
somewhat like a diode.

I believe you can have a N-type vacuum-channel transistor, but not a P-type
vacuum-channel transistor. Even if someone from NASA tells you overwise.

There is some good information in this article, but I disagree with the
P-type vacuum-channel transistor claims.
https://physicsworld.com/a/nasa-scientists-design-a-nanoscale-complementary-
vacuum-field-emission-transistor/

What was old is new again.

So study up and come to the meeting and join me in the discussion.

John Mark Mobley




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