Is it even possible to homebrew a modern computer chip?

I wanna say I read about some high schooler recently making _a_ microprocessor in his garage, but I'm guessing it's a very simple one, not what we would consider a modern design.

Also I could be thinking of something else entirely so, before repeating this, you'll probably want to google it.

no. and even if it were then are people whose job is to make sure it never really takes off.

why? because power.

what do do about it? get power. how to do that? dunno. If I told you then my own purported (and protracted) attempts would diminish. at least we don't get assasinated to death anymore..... ahahahaha (just our characters, andor career prospects, etc)

by modern do you mean just the capabilities of or include the size of as a requirement? If you accept that a DIY processor can be the size of a room and not be portable, then maybe???? Expecting a DIY to be miniaturized, then hellz to the naw

Precursor (https://www.crowdsupply.com/sutajio-kosagi/precursor) is interesting with its use of an FPGA.

That is pretty interesting, thank you!

Nope, even an EUV light source would be close to impossible.

On a technical level, sure. In the bigger picture, I'm concerned that that is simply too esoteric an interest for it to have any significant impact.

Almost any innovation starts like this.

I certainly would _like_ to believe that...I'm gonna have to think about this some.

And tinfoil.

There are better materials to make a Faraday cage out of, but foil is cheap, I'll concede that.

It's pretty hard with tinfoil. Try it with an am radio. It takes several layers, no small gaps to kill the signal.

TIL.

Would it not be easier to find the backdoor and use it to patch itself?

Basically rooting the phone but on a firmware level?

Airplane mode does work. I can put an emf meter up to my Android phone and nothing comes out of it. Same with the device off.

But is it still recording for later transmission? Perhaps!

If you're willing to believe anything can be put in passive mode, you'll absolutely drive yourself mad. There's no way to proove that a device is not listening passively, so of course people will say it is.

Anything with an integrated circuit can be proven to be not operating based on power consumption or switching noise of the transistors in the device.

Modern microphones need input clock to operate, and are physically incapable of listening when the clock is absent.

This gives a trivial way to detect of the device is listening passively, at least on the workbench.

I don't even know what the "mic needs a clock" means. I've never used a microphone that needed a clock. Making a mic that needs a clock just seems like a "WTF were they thinking" kind of thing. Can you elaborate on this concept of requiring a clock for a mic?

The keyword to search for is "digital mems", and of course we are talking individual parts to place on PCB, not the consumer device. Here is one random example: [0]. Somewhat expensive at $1 ea, but that's what you pay for US manufacturer.

This microphones take 2.4 MHz clock and return PDM (pulse density modulation) signal. Does not seem very convinient for old-school analog electronic circuits, but it's pretty trivial to interface with any micro with pulse counter hardware.

And presumably the audio won't have any hum or interference from nearby radio transmitters, which is especially useful in cell phones.

[0] https://www.digikey.com/en/products/detail/cui-devices/CMM-4...

My phone has hardware kill switches for modem, wifi/Bluetooth and mic/camera.

Do those meters work across all frequencies?