Are we ever going to circle back to the notion of creating circuits that can hold more than 2 states? We seem to be doing that for SSDs but not for logic.
Or has the space already been explored and there's nothing there?
Or has the space already been explored and there's nothing there?
For digital, noise-free logic, it's generally more power efficient and physically simpler to have logic gates operate on two cleanly separated states with more gates, than to have bulkier, more complicated gates that do the same thing with combined states. A transistor which is fully on or fully off in a logic circuit uses low power either way (like a wire or a gap in the circuit), but the in-between state uses more power (like a resistor, it produces heat). This is one reason why power consumption goes up with the amount of logic state switching (the in-between resistor-like state occurs briefly during each state change), and also why many-level stable logic states aren't so efficient, except with complicated gates that use many transistors to implement many thresholds.
For non-volatile storage, that doesn't apply. Information density is more important, individual memory cells do not change state often so switching power is less of a thing per memory cell, and the logic sits at the edge of the memory array, shared among many cells. The edge circuitry can afford to be more complicated, to optimise the bulk of the memory array.
In magnetic storage and communication, the signal processing to encode many states in a small signal takes considerable power, but the trade off is worth it.
I checked Mouser just now and memristors are not in stock: https://www.mouser.com/c/?q=memristor
If we are talking about imaginary components, then I think quantistors will change everything.
If you are interested in learning, the idea of memristors (and other computational memory technology) is not to replace traditional memory, but rather to augment small portions of it with increased/additional computational functionality.
For example, you could add a (relatively speaking) extremely small number of memristors to an existing memory module, load two matrices into that area of memory, and reading from the adjacent region of memory would immediately yield the result of multiplying those two matrices. If you could simply instruct the RAM module where the existing data lies, this would be an immense boost in efficiency to AI/deep learning prediction algorithms. Here is a video explanation of how this could be use to perform matrix vector multiplication in O(1): https://youtu.be/30K5i8bdiyg?t=1492 .
That video mentions later that something similar can be used in solving linear and partial differential equations. Applications for deep learning training is discussed at 40:20 .
You'll notice everything discussed in the keynote has experimental results. At 41:27, he mentions that you can actually send images to their memristor chip over their website . Though the link is unfortunately dead, it definitely worked, and was in fact performing neural network computations using memristors over the network.
Without the buffering step, you'll eventually get the middle logic levels drifting (e.g. your "1"s become "0"s or "2"s). Binary gets this for "free" because there's no middle states; this doesn't apply just to a simple buffer, similar details apply to the implementation of all other gates (many of which are rather awkward to implement).
Analog works out for rough calculations because you can skip the buffering process, at the expense of having your calculation's precision limited by the linearity of your circuit.
SSDs are more of a special case, because to my knowledge they're not really doing work on multi-level logic outside of the storage cells. They pump current in on one axis of a matrix, read it out on the other, and then ADC it back to binary as fast as possible before doing any other logic.
Random sidebar: I don't see any constraint like this for mechanical computers, so a base-10 mechanical computer doesn't strike me as any more unreasonable than a base-2 mechanical computer (i.e. slop and tolerance is independent of gear size). In fact, it might be reasonable to say you should use the largest gears that the technology of your time can support (sorry Babbage).
What I was trying to say is that there are things we don't do because they're hard or we don't know how, and there are things that we don't do because we've proven they don't work.
Ternary does have some cool features though.