Your first suggestion summarized: (1) "Let's see what is the most important to measure the tunnel diode IV curve. IMO this is not the scope. You have to see that when increasing the voltage across the diode, the current through it decreases. ..."

Yes, I very much agree that the scope cannot measure the tunnel diode's current and voltage characteristics, though it is very useful, to give a very vivid picture that the I-V curve has a mysterious gap (NDR or Twilight Zone) where the electrons. split itself into two parts, like the Schrodinger Cat, with one part jail breaking, disappearing into the Bermuda Triangle, and reappearing in the free world, ...

So let us forget the scope for a while and focus on how to do the I, V measurements using adj UPS, DMMs, opAmps (which I try to avoid for now, because my audiences are the U15 hobbyists in our local maker's club) etc, ...

Wow, your following story is amazing: "... I think the best way to measure and plot IV curves is based on a computer. Apple II was very suitable for this purpose with its graphic features. The monitor software had a function "plot a point" that could be used by an additional program written in Assembler. In this way, in the late 80s, a few students and I created MICROLAB system, ..."

/ continued from above: "... The AD periphery consisted of 12-bit DAC and ADC. Later, one of these capable students, created MICROLAB BASIC - an expansion to the embedded BASIC. It consisted of a set of assembler drivers called by commands like "IN", "OUT", "PLOT", etc..."

So your MicroLab's (tunnel) diode I-V plotting equipment using Apple 2 and 12-bit ADC/DAC is 20 years ahead of my 64-bit Raspberry Pi and 8-bit DAC/ADC. For our non realtime project, Rpi's 64-bit processing is not relevant, but 12 bit resolution might be just appropriate technology, while my 8-bit PCF8951 ADC/DAC might be too weak.

Your zero resistance stuff is a bit too hard for a Sunday morning reading. Anyway, it is now tea time, So see you later. Cheers.

Oh my goodness, so your MicroLab I-V curve plotter is 20 years ahead of mine. I need to skip my lunch to catch up!

When browsing you the links you just gave me, I suddenly remember that my original question in CD is very long, including a couple of your references, and pictures stating that origins are are from you Wikibooks. But my very long question has been condensed to CD's standard format of 70 words, so many of my references I wish my readers/answers are removed. Anyway, I recovered part of the contents from the Cd's history files, but the formats are incompatible to EE，

tunneldiode.blogspot.com/2020/12/…

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