Posted by a1k0n 12/20/2025
Oh shit, this prompted me to check and turns out TinyTapeout is back to life! https://tinytapeout.com/
If you have a ROM, it's not "no memory".
Needlessly pedantic!
I thought this was pretty cool but the first video didn't play. All this write up and I really just want to see the damn demo in action first! (Edit: reloaded the page and it worked. I still would like to see it on rela hardware!)
You are going to have a hard time doing analog signal processing with memoryless elements. In the linear domain all you can do is apply gain and mix signals together. If you work with memoryless nonlinearities you can do waveshaping, which is generally only useful when applied to special signals (e.g. sine waves).
Any time you want to do frequency-dependent behavior (filtering, oscillation) you need energy storing elements, usually capacitors, sometimes inductors. A capacitor is just like a register: it stores charge, similarly, inductors store energy in the magnetic field. Needless to say these devices are not memoryless. In fact, since the quantity that they remember is a continuous variable, they store a lot of information.
I have no qualms saying a stateful device can have no memory in the addressable memory sense.
I'm not sure where addressable comes in. A digital register is literally a flip-flop (or a bank of flip-flops). It's wired into a larger circuit the same way that a capacitor is.
Bucket-brigade delay lines?
But I'm not really familiar with what that is.
Imagine a pair of MOSFETs connected to a pair of capacitors, and a bunch of those joined together in a chain. All the gates of each one of the pair of MOSFETS are connected together, giving you a "left" and "right" clock input.
When you put a signal in if you pulse the "left" and "right" inputs, it'll store the signal voltage in one capacitor, then pass it off to the next capacitor in turn, like old-timey firefighter handing buckets of water down a line of people.
They used to use this for delaying audio signals before digital memory and analogue to digital conversion was cheap enough to use.
if you have pedantry, it's also not "no memory"
ok, but silicon is doped so it's slightly impure, and CPUs are also silicon and memory is also silicon.
you actually meant "4K gates, no clock, no synchronization, no timing" and maybe a little "not exactly sure when the output is rea... is rea... is ready"