Top
Best
New

Posted by a1k0n 3 days ago

Pure Silicon Demo Coding: No CPU, No Memory, Just 4k Gates(www.a1k0n.net)
422 points | 72 commentspage 2
datameta 2 days ago|
Very impressive stuff. I used to frequent the JS demoscene, mostly dwitter - but this is on a whole other level.

Oh shit, this prompted me to check and turns out TinyTapeout is back to life! https://tinytapeout.com/

openinfrared 3 days ago||
Really cool!
Uptrenda 3 days ago||
[flagged]
Dwedit 3 days ago||
If you have registers, it's not "no memory".
hackernudes 3 days ago||
If you have flip flops, it's not "no memory".

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!)

a1k0n 3 days ago|||
Ah that's what I get for self hosting. What browser?

https://youtu.be/7xPS-0nydms

a1k0n 3 days ago||
And this thread shows all of them on real hardware: https://x.com/i/status/1992802154370011595
jayd16 3 days ago||||
I don't know. Analog signal processing is clearly less memory than a register, no? So a line exists somewhere and I think it's way before no RAM.
RossBencina 2 days ago|||
> Analog signal processing is clearly less memory than a register, no?

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.

jayd16 1 day ago||
I would say that there's a difference between simply a stateful circuit using capacitors etc and a digital register, at least in so far as a "hey look what I made" kind of post.

I have no qualms saying a stateful device can have no memory in the addressable memory sense.

ErroneousBosh 3 days ago|||
> Analog signal processing is clearly less memory than a register, no?

Bucket-brigade delay lines?

jayd16 3 days ago||
I'm not saying every analog signal processor is surely memory free, simply that you can imagine one that is.

But I'm not really familiar with what that is.

ErroneousBosh 3 days ago||
They're a kind of analogue dynamic memory. I'd hesitate to call them RAM because the Access is not Random, but they are a kind of shift register and early computers used those for RAM.

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.

fsckboy 2 days ago||
bucket brigades were also used to read large scale sensors like a CCD camera. they are more efficient in their use of die space because you need fewer data paths; they don't need to be digital either, each bucket can be analog for "grey" scale
fsckboy 2 days ago|||
>Needlessly pedantic!

if you have pedantry, it's also not "no memory"

jonathrg 3 days ago|||
And I better not see any capacitors on there remembering any charge!
layer8 3 days ago||
Even simple wires can be memory: https://en.wikipedia.org/wiki/Delay-line_memory#Electric_del...
fsckboy 2 days ago|
>Pure Silicon Demo Coding: No CPU, No Memory, Just 4k Gates

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"

chrisjj 2 days ago|
There is sync and there is timing. Else there'd be no meaningful image.