Nostr notes by Andrew Zonenberg

Hypothesis: genderfluid is not a classical gender identity. The ...

2026-10-29T00:30:50Z

Hypothesis: genderfluid is not a classical gender identity.

The actual identity is that of a superposition, with the wave function collapsing to one gender or another each time it's measured.

Which raises the question of whether multiple entities can have entangled genders such that measuring them at different, spatially separated locations yields correlated measurements.

Ooh interesting PMMA depolymerization work out of ETH Zurich. One ...

2026-10-27T02:41:53Z

Ooh interesting PMMA depolymerization work out of ETH Zurich. One step closer to real viable plastic recycling... Not melt it down into impure mystery meat, not burning or shredding, but actual depolymerization to clean methyl methacrylate ready for reuse

https://ethz.ch/en/news-and-events/eth-news/news/2026/10/new-method-makes-acrylic-glass-recycling-economically-viable.html

https://www.nature.com/articles/s41557-026-02232-4

Do I know anyone in the greater Seattle area with a rubidium ...

2026-10-26T05:17:50Z

Do I know anyone in the greater Seattle area with a rubidium clock and a spare weekend to run an experiment with me?

Is FTDI trying to silently hide their past sins? Early FT232Hs ...

2026-10-26T01:48:51Z

Is FTDI trying to silently hide their past sins?

Early FT232Hs had a truly cursed package design with exposed lead frame at extremely fine pitch around a very small thermal pad. And it would short if you looked at it funny and had anything but an absolutely perfect paste print.

I know this was real, I've personally had to rework under-chip bridges caused by this boobytrap.

But in the current datasheet revision I can't find any mention of it, distribution websites show a standard (sane) QFN, and I can't find any PCNs or datasheet revision history talking about a lead frame change.

EDIT: my memory is to blame. It was the 2232h not the 232h, and there was in fact a PCN

I mean this is very common for folks who dont understand the ...

2026-10-22T22:11:30Z

In reply to nevent1q…xhjq
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I mean this is very common for folks who dont understand the power demands of IT and T&M gear.

When I air conditioned the garage that turned into my lab the contractor tried to spec like a 5K BTU/hr window unit or equivalent. I very rapidly talked them out of that stupidity showing my calculations for expected thermal loading and we put in a 18K BTU/hr minisplit.

Which has been struggling to keep up some summers.

Today is one of those days when people might not look at me ...

2026-10-20T18:42:40Z

Today is one of those days when people might *not* look at me like I have three heads when I say disabling root certificates from smaller CAs in countries you don't do business with can be a good mitigation against MITM by shrinking the pool of roots an attacker would have to compromise to make a cert you trust.

Like a lot of countries have private CAs for signing their own government websites. How many of you would have problems if your users couldn't reach the Turkish or South African government? If you're not in one of those countries, probably not a lot.

I apologize for nothing. ...

2026-10-20T03:02:46Z

I apologize for nothing.

Post with cw "selfie ec" but it's a selfie of ...

2026-10-18T00:51:11Z

Post with cw "selfie ec" but it's a selfie of somebody with the European Commission

Self deprecating: when you grab a marker and write [[deprecated]] ...

2026-10-17T16:04:37Z

Self deprecating: when you grab a marker and write [[deprecated]] on your body

Me: "i asked claude..." Fedi: "eew" Me: "no ...

2026-10-09T02:11:44Z

In reply to nevent1q…v2vg
_________________________

Me: "i asked claude..."
Fedi: "eew"
Me: "no he actually had some great ideas. I went over his house and he gave me this book that he said was a great introduction to the subject"

lol. Me: "Me and Claude built this" Fedi: "go away ...

2026-10-09T02:07:15Z

In reply to nevent1q…zjvx
_________________________

lol.

Me: "Me and Claude built this"
Fedi: "go away slop"
Me: "no seriously it took us all weekend, here's a pic" (posts selfie of me and Claude sitting at a crowded workbench"

I wish I had a friend named Claude who was an engineer or ...

2026-10-09T02:05:08Z

I wish I had a friend named Claude who was an engineer or software dev.

We could have so much fun trolling people.

chat what does this icon in my steam library mean ...

2026-10-06T23:49:02Z

In reply to nevent1q…5w9p
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chat what does this icon in my steam library mean

Why are all the best puzzle games so expensive and why won't ...

2026-10-06T23:43:15Z

Why are all the best puzzle games so expensive and why won't the state department let me share them?

I just wanna have fun with frens but i don't have a few hundred k$ and an export license :(

why does a vector graphics format allow active content in the ...

2026-10-06T15:29:41Z

In reply to nevent1q…vnt6
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why does a vector graphics format allow active content in the first place? This has never made sense to me

almost certainly neural network models of typing and typos

2026-09-22T16:43:26Z

In reply to nevent1q…p37a
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almost certainly neural network models of typing and typos

My local grocery store has an aisle labeled "conven. ...

2026-09-20T13:28:19Z

My local grocery store has an aisle labeled "conven. breakfast" where all the granola bars, poptarts, etc are sold. Presumably this is an abbreviation of "convenient".

My brain keeps trying to interpret that as an abbrevation of "convent" and I picture a bunch of nuns sitting around a table eating poptarts

I have no problem paying a decent amount for something I will ...

2026-09-20T13:04:39Z

In reply to nevent1q…xy8p
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I have no problem paying a decent amount for something I will probably keep in the lab for a decade.

The main thing is, I want it to be local IP capable and not run through an outside cloud service or something, and not have to write custom firmware.

If I'm gonna have to learn a new platform and write my own firmware I might as well just DIY it with a raw panel and STM32.

I'm looking for something that I absolutely could DIY but ...

2026-09-20T12:55:14Z

I'm looking for something that I absolutely *could* DIY but am pretty sure exists as a commercial product.

* Large format red/black/white (yellow optional) eink display, 7 inch or so
* Ethernet or wifi
* Local push based update (i.e. I can make a POST request or something directly to the device to dump an image onto it without needing to go through a cloud server or be on a VLAN with internet access. Timer-based pull update (device downloads an image at regular intervals) is also acceptable but less desirable
* Good documentation

Anybody have suggestions? I see random eink displays all over the internet but most either provide no obvious docs on how to update them, or want to go through some kind of cloud management system.

Tempted to just buy a panel and bolt a stm32 or something on it

ok we need to hear how that happened

2026-09-13T20:52:00Z

In reply to nevent1q…vj00
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ok we need to hear how that happened

Biblically accurate nfpa diamond ...

2026-09-12T18:04:53Z

Biblically accurate nfpa diamond

Hashtag JustDebuggingThings ...

2026-09-09T06:46:33Z

Hashtag JustDebuggingThings

And yet another shipping WTF. Why would I ever choose 3-day ...

2026-09-07T19:34:41Z

And yet another shipping WTF.

Why would I ever choose 3-day delivery for a higher price than 2-day delivery?

We all know slop company logos look like buttholes, but has ...

2026-08-27T02:42:51Z

We all know slop company logos look like buttholes, but has anyone made one that has the hands and ring yet?

and i doubt the rest of the aircraft is Linux there's a lot ...

2026-08-23T14:25:30Z

In reply to nevent1q…ulna
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and i doubt the rest of the aircraft is Linux there's a lot of weird rtoses and vxworks and such in aviation

foreflight is ios only but I'm not sure of the details of the ...

2026-08-23T14:24:42Z

In reply to nevent1q…lpl4
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foreflight is ios only but I'm not sure of the details of the market forces that led to them being so dominant. I'm sure other efb software for e.g. android exists but basically nobody uses it by comparison

and most importantly unlike e.g. android auto it is a completely ...

2026-08-23T00:28:00Z

In reply to nevent1q…6ds5
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and most importantly unlike e.g. android auto it is a completely standalone device that has no connection to the aircraft, its failure (other than like catching fire or something) can't impact flight systems whatsoever.

I wish cars were built the same way...

Characterizing my first draft of the 10 GHz bandpass filter. ...

2026-08-22T22:58:42Z

Characterizing my first draft of the 10 GHz bandpass filter.

Are there any virtualization platforms that will create a fake ...

2026-08-12T19:29:11Z

Are there any virtualization platforms that will create a fake vTPM that isn't actually locked down?

Like, the VM thinks it has a TPM but I can still see and modify bitlocker keys and UEFI variables etc arbitrarily from the host system

Years ago I remember hearing a story of a real-life Shrek who ...

2026-08-12T12:15:57Z

Years ago I remember hearing a story of a real-life Shrek who just wanted to live in a swamp and be left alone.

His family had once owned a lot of land, maybe a farm, in the area but most of it had been sold off and was being gradually developed. He still owned a house and a small plot of land though, and couldn't stand the encroaching suburbs and strip malls.

After a bit of exploring he discovered some streams and swamps in a neighboring, vacant lot and contacted the state about it. Before long, that land was legally a protected wetland that would be expensive or impossible to develop, guaranteeing him a buffer against the approaching subdivisions.

But this made the land decrease in value, since no developer would buy it. So he picked up this plot for a fraction of what a buildable plot in the same area would cost.

After a bit of excavation and streambed restoration, he expanded the wetlands right up to the next property line. But this also meant a sizeable chunk of the neighboring lot earned protected wetland status, making *it* unbuildable and reducing its value.

I forget how many times he repeated the process but the end result was him owning a small house surrounded by a large amount of permanently unbuildable wetlands, to be left in its natural state forever. IIRC he was a guy so "bog witch" doesn't really fit, but can you be a bog wizard?

Fun engineering challenge if anyone has ideas: The DisplayPort ...

2026-07-30T18:35:17Z

Fun engineering challenge if anyone has ideas:

The DisplayPort auxiliary channel appears to reuse opcodes for request and completion packets, and uses generally the same framing. This means that, to a first order, if you have a single packet, or a capture that starts in the middle of a long burst of transactions and don't know if you are at an even or odd packet boundary, it is not trivially possible to unambiguously decode the traffic.

Is there a heuristic that you can apply to the first few packets in a capture to determine which one is a request vs a completion and correctly phase the capture?

For decades there's been a conflict between governments ...

2026-07-22T15:35:43Z

For decades there's been a conflict between governments wanting to get access to people's private data and people trying to keep them out.

Over the years I've gradually come to the conclusion that the stable "Goldilocks zone", where there's the least likelihood of a major swing that makes things worse for everyone, is *not* the privacy utopia where devices are invulnerable, or a police state where anyone with a badge who asks can root through all your data, or a fictional engineered cryptographic backdoor that''s somehow only exploitable by "the good guys".

Instead, it's the state where devices (especially phones) are breakable, but only through attack vectors that require physical access, have a high per-device cost, and are not 100% reliable. Things like "solder to an internal layer trace on the logic board to glitch it" or "FIB a per-device key out of the SoC then bruteforce the password".

I'm not saying we should be adding deliberate backdoors - quite the opposite, since these are very likely to make entry *too* easy.

But if devices become completely invulnerable, I expect we will see something like chat control turned up to 11 where the pressure to find some way in becomes unbearable and we end up with CALEA-style entry points that turn devices into total spyware with no privacy at all.

So IMO the ideal balance is where there is no viable remote attack vector, trivial drive-by USB etc attacks a la Cellebrite are blocked, but if a government has a phone off a body and are willing to spend $100K+ of lab time to have a >50% chance of breaking into *that one device*, destroying it in the process, without it easily scaling to the next, there's a good chance they can do so.

And this level of difficulty is juuust easy enough that they aren't spending the same money lobbying politicians to make it easy to break into every device belonging to an opposition party or something. They still try of course, they always want more, but they can't claim to congress that the guy who shot senator X will never be caught because they couldn't break the phone they found at the scene.

You know your device was confiscated (or are dead and not around to complain), it's not viable to do to everyone crossing a border or who was in a certain geofenced area, etc. There's no practical way to scale physical attacks to mass surveillance.

If you're ever looking for an Italian restaurant and ...

2026-07-14T02:48:49Z

If you're ever looking for an Italian restaurant and don't have a phone or map, but do have a gamma spectrometer, just look for 511 keV annihilation lines and follow them to their source. If you find them from multiple restaurants, the weaker line is the one to eat at.

No matter how well they try to clean cooking utensils between making pasta and antipasto, some mixing is unavoidable which creates a distinct gamma signature.

A smaller annihilation peak is a good sign of more thorough cleaning and better general food safety practices.

Nostr event nevent1qqswf00pwuxulfh5uw5t7exmjrsfpnvmz3ec87v0d9fx2k4wexg7juczypc9zuup4v7rsgcsa9tljqx6z24c9496j9myz4sa50mluqx90efdkzut0fa

2026-07-14T02:41:15Z

The existence of prosciutto implies the existence of consciutto

The landscaping service has arrived to trim the bushes in our ...

2026-07-09T15:23:28Z

The landscaping service has arrived to trim the bushes in our front yard.

He's great, doesn't even bill us

Iperf from soldering bench to the microscope bench is happy at 40 ...

2026-07-02T12:41:08Z

In reply to nevent1q…9yvx
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Iperf from soldering bench to the microscope bench is happy at 40 Gbps which makes sense because the switch to switch link, at least, is only 40G

Why you have to call it gigabit-ethernet in the CLI when it's ...

2026-07-02T12:38:32Z

In reply to nevent1q…tf4g
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Why you have to call it gigabit-ethernet in the CLI when it's a 100G pipe is another question lol

It was in fact MTU on the switch-to-switch trunk. For some reason ...

2026-07-02T12:38:09Z

In reply to nevent1q…vxs3
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It was in fact MTU on the switch-to-switch trunk. For some reason the MTU on trunk ports defaults to 1500 *including* the 802.1q tag.

"set interface gigabit-ethernet xe-1/1/9 mtu 1518" fixes it.

Moved the microscope bench workstation over to the new switch. ...

2026-07-02T12:36:17Z

In reply to nevent1q…lk2s
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Moved the microscope bench workstation over to the new switch. Same issue, SSH from the same client to it fails. So it's not specific to the Mac.

Anyway, I'll be moving my client over to the new switch soon ...

2026-07-02T12:27:34Z

In reply to nevent1q…2h9q
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Anyway, I'll be moving my client over to the new switch soon and I'll know a lot more when that happens.

But let's continue moving lower priority loads first. I expect a few more switch reloads are in the pipeline from configuring additional breakouts etc

OK yeah my client is attempting to push a 1514 byte (with vlan ...

2026-07-02T12:21:25Z

In reply to nevent1q…j4yk
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OK yeah my client is attempting to push a 1514 byte (with vlan tag) frame out to the mac, which isn't seeing it.

Not sure if it's being dropped at the trunk between the switches or as the packet is going out to the mac or what.

Started moving lower priority services over. So far the only ...

2026-07-02T12:14:56Z

In reply to nevent1q…vyan
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Started moving lower priority services over. So far the only thing that's broken is SSH to the Mac Mini. It hangs waiting for a SSH2_MSG_KEX_ECDH_REPLY which IIRC is a fairly large packet which makes me think it might be a MTU issue.

The smol switches have per-port indicator LEDs for breakout mode. ...

2026-07-02T11:59:35Z

In reply to nevent1q…a6ed
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The smol switches have per-port indicator LEDs for breakout mode. The big one doesn't - in fact the link light doesn't even seem to go on in breakout mode.

Not a huge deal, you can see the correct link state in the CLI and I rarely actually look at the front panel of a switch. But a mild annoyance.

All of the CLI commands are totally different. Building the ...

2026-07-02T11:32:10Z

In reply to nevent1q…zkz6
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All of the CLI commands are totally different. Building the muscle memory for "run show interface brief" instead of "do show int status" etc will take time.

Starting to bring up the PicOS switch. Interesting findings so ...

2026-07-02T11:30:36Z

Starting to bring up the PicOS switch.

Interesting findings so far... changing port breakout mode requires a reboot (not uncommon, so do most of my other switches).

More annoying is that breakout ports all have to run at the same speed, you can't mix 1G and 10G subinterfaces on a QSFP breakout, or 10G and 25G on a QSFP28.

Not a HUGE deal, I can just pick one quad to break out in 1G mode for those ports, but it does mean for a lab environment switching speeds back and forth will mean physically swapping fibers not just a CLI command.

Has anyone done any investigation into the demographics and ...

2026-07-01T23:16:41Z

Has anyone done any investigation into the demographics and origin stories of catgirls, puppygirls, etc?

For reasons I don't understand it seems like there's a strong bias towards puppygirls in the younger generation (20s/teens) while catgirls tend to be older (30s and up). But why is this? Did lolcats traumatize the younger folks or something?

Nostr event nevent1qqsyxmrmark4nkevddtzqxjxxmn8dpfxm86ua97cj0k0duvfpnzytnszypc9zuup4v7rsgcsa9tljqx6z24c9496j9myz4sa50mluqx90efdkxsvl6s

2026-06-28T14:52:39Z

Bnuuy

Older terminals have a LE NIN key in the same position

2026-06-26T02:46:45Z

In reply to nevent1q…n94n
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Older terminals have a LE NIN key in the same position

Bit into a chocolate truffle from a local candy shop that was a ...

2026-06-19T08:05:19Z

Bit into a chocolate truffle from a local candy shop that was a kind of hemispherical shape, perhaps made from a flat chocolate base that had a blob of filling put on it and then encapsulated in more chocolate.

And as I'm looking at the seam between the two segments the first thing that comes to mind is... Wouldn't it be cool to freeze one of these in LN2, cross section, polish, maybe ion mill, then do like SEM/EBSD to look at the cocoa butter grain structure around the weld line?

I think I have a problem.

LLMs are fundamentally incompatible with free software. This ...

2026-06-18T16:37:01Z

In reply to nevent1q…uc22
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LLMs are fundamentally incompatible with free software. This should be your entire policy statement.

Yeah they don't charge a registration fee so this would be ...

2026-06-18T15:15:36Z

In reply to nevent1q…u7wa
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Yeah they don't charge a registration fee so this would be all me.

My gut feeling is that for the amount I would potentially charge and this being most likely a one-time thing or at best once a year, it's probably not worth the hassle.

EU folks: What are the tax etc. implications if I, as a non EU ...

2026-06-18T14:59:59Z

EU folks: What are the tax etc. implications if I, as a non EU resident/citizen with no existing business connection to the EU, want to offer a paid training at a conference in Europe? Do I have to collect VAT or sales tax or something along those lines? Or if I'm not a European citizen/business or collecting less than X million EUR in the tax year am I tax-exempt?

Is this such a paperwork nightmare I shouldn't even attempt it unless an existing EU entity wants to handle all of this and just contract with me for my time?

instructions unclear have root on my guitar now

2026-06-16T02:16:42Z

In reply to nevent1q…gd29
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instructions unclear have root on my guitar now

Metal 1, coming up on the underside of the die. You can see all ...

2026-06-11T03:47:37Z

In reply to nevent1q…rk98
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Metal 1, coming up on the underside of the die. You can see all of the little wire bond rings, 4-5 concentric rings of wire bonds.

I sanded up to the silver epoxy but not into the silicon to avoid potentially cracking it. So we should get a really clean die back side at the end of this.

Metal 2. This turned out really good, planarity actually ...

2026-06-11T03:32:09Z

In reply to nevent1q…t862
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Metal 2.

This turned out really good, planarity actually *improved* as I got deeper which surprised me because usually it's the opposite. Not sure if I was getting the feel of the part and correcting as I saw unevenness, or something about the way it was flexing, or what. But it seems like there is less edge rounding now.

There's a few obvious thicker zone fills, maybe power tracks? And a lot of signal routes, including some length-matched diff pairs.

Most of this layer is one big zone fill that I suspect is ground but have not probed to confirm.

Metal 3. Lost a bit of the edges especially along the south side ...

2026-06-11T00:41:49Z

In reply to nevent1q…lq2l
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Metal 3. Lost a bit of the edges especially along the south side but got most of it (and you can see some of the missing parts in the previous image).

Looks like mostly power rails, likely VCCO / VCCINT / VCCAUX although I haven't mapped out which is which yet. Possibly some ground too. And a few IOs in oddball places.

I could have stopped to image as the ring of copper shrunk ...

2026-06-11T00:17:47Z

In reply to nevent1q…5d54
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I could have stopped to image as the ring of copper shrunk inward, but I had good enough views through the soldermask that I didn't bother.

Here's the next pass, with metal 4 fully uncovered and the edge of metal 3 polished away. We can see metal 2 and even 1 coming into view around the very corners.

I want to experiment with using the mill for substrate thinning and see if this might avoid the edge rounding issue (assuming the substrate itself isn't warped). I'd likely still have to sand the last little bit, but it might be an improvement? I'll run a test of that later.

After a first pass of sanding, there's some edge rounding ...

2026-06-11T00:12:02Z

In reply to nevent1q…wgjz
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After a first pass of sanding, there's some edge rounding (hard to avoid, although it got less pronounced later on when I switched to a fresh sheet of sandpaper) and we see clean copper around the edges while the middle is just scuffed soldermask that's almost impossible to see anything through.

But the good news is all of the layout of the bottom copper layer (let's call this substrate metal 4) can be seen through the soldermask in the first image, so nothing too valuable was lost

So BGAs have been a bit of a pain in my behind for a while from ...

2026-06-11T00:04:47Z

So BGAs have been a bit of a pain in my behind for a while from an IC RE perspective.

Specifically, wirebonded BGAs with multilayer organic substrates. I use 70% nitric acid at home for decapsulation rather than fuming (more stable in storage, safer to work with, and far easier/less expensive to source) which doesn't do a great job of etching the BT resin compared to the silica filled molding compound.

Usually what happens is that the overmold disintegrates rapidly leaving the bare die stuck to a slab of fiberglass, then the substrate slooooowly decomposes over the course of 30+ minutes with the die slowly being damaged by bond pad underetch, banging into debris in the beaker, repeated cleaning and handling steps, etc.

So as an experiment, I'm trying a different strategy: use 220 grit wet sanding, by hand, to remove the substrate before switching to chemical processing.

As a bonus, if you work carefully and take photos at intermediate steps it should be possible to reconstruct most/all of the substrate netlist and figure out the mapping of BGA lands to wire bond pads.

Here's a very old Artix-7 part (from before they started putting datamatrix codes on them)

curious: is anyone in the US and/or EU pushing legislation to ban ...

2026-06-06T18:01:49Z

In reply to nevent1q…ptuu
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curious: is anyone in the US and/or EU pushing legislation to ban commercial residential proxies?

Soo according to Anthropic ...

2026-06-05T16:22:34Z

Soo according to Anthropic (https://www.anthropic.com/institute/recursive-self-improvement) they are thinking of slowing or halting frontier model development, but only if their competition does so as well and they have a nuclear-disarmament-style inspection process to verify this is the case.

There's two possible reads on this, of course.

The cover story is that they are worried about the models self-improving and becoming God and running away etc. Because they're vibe-coding 80% of their new stuff and model collapse is totally not a real thing.

My preferred interpretation is that training costs are getting out of hand, they are terrified of shareholders finding out how much they are spending on training when they go public, so they want to cut back but they're afraid of falling behind and losing their edge so the only way they're willing to do so is if they can be assured the competition isn't out-spending them.

There has to be an antitrust case here if somebody is willing to bring one (good luck in today's political climate but hey I can dream)

gluten free filament

2026-06-04T05:29:40Z

In reply to nevent1q…v734
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gluten free filament

The big cisco is emptying out as i move stuff over to 40g or 4x ...

2026-05-28T00:18:44Z

In reply to nevent1q…3mjz
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The big cisco is emptying out as i move stuff over to 40g or 4x 10g breakouts.

Pulling sooo many 10g optics. I might have to start unloading 10g sfps and only keep 10/25g dual rate capable ones

Now to dig up all of those MPO to LC breakout cables I've had ...

2026-05-27T23:55:32Z

In reply to nevent1q…cggs
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Now to dig up all of those MPO to LC breakout cables I've had lying around unused...

New switch setup time ...

2026-05-27T23:41:28Z

New switch setup time

These also look like poly resistors but are a different color, ...

2026-05-25T04:53:03Z

In reply to nevent1q…r5zt
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These also look like poly resistors but are a different color, maybe they have two poly layers with different silicide doping or one of them is a resistive metal layer or something

Poly resistors ...

2026-05-25T04:52:14Z

In reply to nevent1q…ac2s
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Poly resistors

Random logic showing 3 metal layers and what looks like maybe ...

2026-05-25T04:51:38Z

In reply to nevent1q…dhrg
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Random logic showing 3 metal layers and what looks like maybe poly resistors

I've figured out what foundry made a lot of chips based on ...

2026-05-25T04:50:51Z

In reply to nevent1q…gzf9
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I've figured out what foundry made a lot of chips based on various hints from fiducials and metal fill etc.

But this is the first time I've seen someone actually write the foundry and process on the mask set. Makes the ID simple lol

I wonder if any of these people still work at Qualcomm? ...

2026-05-25T04:49:52Z

In reply to nevent1q…a5au
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I wonder if any of these people still work at Qualcomm?

Took a quick break but the PM7500 is done, cleaned, and imaged. ...

2026-05-25T04:48:50Z

In reply to nevent1q…ju7y
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Took a quick break but the PM7500 is done, cleaned, and imaged.

Sure looks like a PMIC. Lots of big metal polygons and multi-bonded nets that are probably inputs and outputs for LDOs and buck converters.

Made on an older, 3-metal planarized process.

https://siliconprawn.org/map/qualcomm/pm7500/azonenberg_mz_mit20x/

A more normal amount of NO2 generation (now that I feel safe ...

2026-05-25T02:38:21Z

In reply to nevent1q…smpk
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A more normal amount of NO2 generation (now that I feel safe taking off my gloves and letting it sit for a bit, i can take pics)

For reference usually I see very thin wisps of NO2 at the lip of ...

2026-05-25T02:22:22Z

In reply to nevent1q…f22w
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For reference usually I see very thin wisps of NO2 at the lip of the beaker by the watch glass that become invisible as soon as they mix with the air, this was throwing out enough that I saw visible brown puffs moving up from the beaker and remaining visible all the way up to the top of the hood. Faint, but visible.

Like, I knew it was going to react - my plan was to let it sit ...

2026-05-25T02:20:32Z

In reply to nevent1q…vdzk
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Like, I knew it was going to react - my plan was to let it sit there at room temp until most of the copper was gone, and only begin heating to attack the organics after I had taken off the copper.

But with this much copper it seemed to be entering thermal runaway, self-heating and increasing the rate of reaction to the point that I was worried about whether the filtration in the fume hood would be able to cope with the amount of NO2 it was throwing off.

Maybe I should get like a cold water bath or something to put the beaker in when I resume? I wasn't expecting it to get this spicy at this scale (~5 ml of acid iirc).

Hmm, I perhaps could have seen this coming. As soon as I added ...

2026-05-25T02:17:41Z

In reply to nevent1q…8a2j
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Hmm, I perhaps could have seen this coming.

As soon as I added the acid to the VSC8512, with the large copper plane that I had sanded the soldermask off of to image, it started reacting aggressively even at room temperature and throwing off more NO2 than I was comfortable with.

I ended up pouring the acid off to a separate beaker to let things calm down a bit. Will give it a few minutes then see how much copper is left... I might want to do a pre-etch with a dilute nitric solution or something so i can remove the remainder of it without it getting too energetic.

Everything but the acid is prepped. Time to glove up and get ...

2026-05-25T02:08:32Z

In reply to nevent1q…8h3t
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Everything but the acid is prepped. Time to glove up and get spicy, won't be posting for a while

And with that I think I have enough components to keep this wet ...

2026-05-25T02:03:45Z

In reply to nevent1q…ser0
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And with that I think I have enough components to keep this wet lab session busy.

Time to fire up the fume hood...

Next, probably also from the same device, a Qualcomm PM7500 PMIC. ...

2026-05-25T01:19:38Z

In reply to nevent1q…v2kd
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Next, probably also from the same device, a Qualcomm PM7500 PMIC.

112 pin dual row QFN (gross)

Next is another Qualcomm part with a very similar part number, ...

2026-05-25T01:02:22Z

In reply to nevent1q…r678
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Next is another Qualcomm part with a very similar part number, the RFR6500. Seems to be an early generation CDMA receiver from circa 2005. This must have come out of one of my old phones, although I don't think I ever used a CDMA based carrier in that time frame (T-Mobile was GSM based).

I had a Samsung SGH-T439 as my first phone, perhaps this was the chipset from it?

Nothing noteworthy package wise, just a 56 pin punch singulated QFN.

Next is a Qualcomm MSM7500, seems to be part of a very old phone ...

2026-05-25T00:45:34Z

In reply to nevent1q…s6v9
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Next is a Qualcomm MSM7500, seems to be part of a very old phone chipset with an ARM1136JF-S.

Maybe from an embedded cellular module or something? It was sitting as a loose chip in my microscope-food bin and I have no record of its origin.

It's very sticky on one side, some kind of adhesive or thermal compound residue that didn't come off with acetone. I have no special interest in the part so didn't bother trying to clean it further (plus it wasn't obscuring any markings)

The underside is... weird. It's 28 balls square with three concentric rings, each consisting of two rows of balls then a void space, then a bunch of power/ground balls in the middle. This much is normal.

But there's some strange gaps in the soldermask between the rings, and almost all of the balls seem to have connections going to these void areas. I wonder if there is some kind of test point or plating ground or something in this area that is removed late in the packaging process? Never seen anything like this before.

Prepping some chips for a decap run as I do the lab cleanout. ...

2026-05-25T00:27:40Z

Prepping some chips for a decap run as I do the lab cleanout.

First on deck (other than the VSC8512 I prepped a while back) is a DisplayLink DL-5900. Seems to be some kind of USB displayport adapter? No idea where it came from.

Brochure from a vendor found while cleaning out the lab. ...

2026-05-25T00:06:49Z

Brochure from a vendor found while cleaning out the lab.

Presented without comment

STMicro finally released a security advisory related to a silicon ...

2026-05-21T17:37:28Z

STMicro finally released a security advisory related to a silicon errata I found last year so I can talk more freely about it https://www.st.com/resource/en/security_bulletin/sb0070-risaf-limitation-about-pcie-region-protection-on-stm32mp25xx-stmicroelectronics.pdf

Tl;dr the STM32MP2 AXI firewall (RISAF) does not fully block transactions to the PCIe region that are prohibited by register settings.

Writes have the data replaced with 0x00, but still execute (so an attacker who should not be able to touch the device can write zeroes to any location in the BAR of their choice).

Reads have the response data replaced with 0x00 as seen on the bus, but any side effects of the read like clearing flags or popping a fifo will still execute.

In short, it seems to behave as though the AXI data channel is blocked but not the control channel.

The security violation interrupt still fires so the trustzone monitor will be aware of the issue, but depending on the application it may be too late since the register write already happened.

I found this by accident while trying to bring up the STM32MP2 bare metal and couldn't understand why all of my PCIe accesses were acting funny. So if anyone is wondering why I went dark all of a sudden on that side project, now you know why.

Fun engineering/privacy problem: design a device that plugs into ...

2026-05-15T03:04:08Z

Fun engineering/privacy problem: design a device that plugs into an ESP32 based sensor node that has a microphone and reports ambient noise levels in dBa via MQTT or similar.

That's the easy part.

The hard part is to do so in a way that you can prove it's incapable of being used as a bug/listening device even in the worst case scenario (attacker running arbitrary code on any programmable component).

My initial thought is to record audio from a MEMS mic into a tiny MCU with limited RAM capacity, then report results to the main system processor through some kind of R-C low pass filter that only lets like one bit per second pass through.

Or maybe a bank of analog filters and peak hold blocks? I want proper weighted dBa.

have you left a wrench on top of the mill drawbar yet?

2026-05-14T02:37:52Z

In reply to nevent1q…4rrf
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have you left a wrench on top of the mill drawbar yet?

this is what happens when a person who doesn't eat any animal ...

2026-05-13T02:35:41Z

In reply to nevent1q…pdn5
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this is what happens when a person who doesn't eat any animal products rubs a balloon through their hair and builds up an electrostatic charge

Can't link to full 800mpix res because siliconprawn is being ...

2026-05-10T13:45:08Z

Can't link to full 800mpix res because siliconprawn is being derpy, but this is clear enough to see all of the traces so good enough for now.

Substrate of a VSC8512 seen from the underside, after sanding off solder mask. The silver marks are solder residue showing where the BGA balls had been.

This image is mirrored to match the datasheet orientation, as if you were looking at the substrate from the top of the package. Ball A1 is at the northwest corner.

Enterprise Role Play (ERP), sometimes also Enterprise Resource ...

2026-05-04T10:44:03Z

Enterprise Role Play (ERP), sometimes also Enterprise Resource Play: A unique form of fetish role play.

Unlike more popular fantasies such as boss/secretary focused on power relationships in an office environment, in ERP the business processes themselves are central to the scenario.

ERP participants can create elaborate scenarios involving fictional purchasing departments, legal teams, contract negotiations, and more. Large group ERP scenarios sometimes even extend to the point of renting out vacant space in an office park and acquiring demo licenses of SAP or a competing software package to make the fantasy more realistic, or even traveling to a remote ERP group's dungeon to roleplay a merger or acquisition.

As with more conventional roleplays in the S&M context, consent is critical in ERP. If participants are expected to invest significant real-world money in software licenses, make sure this is agreed upon by everyone in advance. The outcome of all merger scenarios should be pre-briefed; attempted hostile takeovers of another dungeon are extremely frowned upon and can result in participants being banned from future events.

The optic is NOS straight from the tray ...

2026-05-02T16:41:49Z

In reply to nevent1q…6qu9
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The optic is NOS straight from the tray

Did i put this in backwards or something? The fiber isn't ...

2026-05-02T16:41:03Z

Did i put this in backwards or something? The fiber isn't clicking

and "Penelope" with "cantaloupe".

2026-04-27T20:23:45Z

In reply to nevent1q…8pd6
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and "Penelope" with "cantaloupe".

don't forget "gorilla" rhymes with ...

2026-04-27T20:22:44Z

In reply to nevent1q…hmk5
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don't forget "gorilla" rhymes with "quesadilla" too

The existence of the New York Post implies the existence of the ...

2026-04-21T22:32:58Z

The existence of the New York Post implies the existence of the New York GET and HEAD

Pulled all but one dimm out of each. No change in behavior

2026-04-19T07:52:28Z

In reply to nevent1q…ah0u
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Pulled all but one dimm out of each. No change in behavior

oh. And the machine that is bootlooping originally came up after ...

2026-04-19T07:42:23Z

In reply to nevent1q…e8uw
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oh. And the machine that is bootlooping originally came up after reboot enough that i could ping and start an ssh connection but not make it all the way to a shell. No idea what was going on there, had no visibility into the failed state

Already pulled the GPUs from both, both because debugging ...

2026-04-19T07:35:23Z

In reply to nevent1q…4kje
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Already pulled the GPUs from both, both because debugging supermicro stuff is easier using the VGA port, and to reduce PSU load in case that was part of the problem.

The two media machines, also running Trixie with the same ...

2026-04-19T07:34:58Z

In reply to nevent1q…uwta
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The two media machines, also running Trixie with the same filesystem mounted, are unaffected.

The two failed machines both have Supermicro X12SPI-TF mainboards. One has a recently acquired secondhand Xeon 8362, the other a 5320 that had previously lived in my VM server for the last few years and had no problems.

RAM on both is recently installed, but hand-me-downs from other machines with no errors during POST or operation. Everything is ECC.

The crash hit all 3 of my physical workstations running Debian ...

2026-04-19T07:31:16Z

In reply to nevent1q…jxgt
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The crash hit all 3 of my physical workstations running Debian Trixie, but not the VM running Trixie, or the xcp-ng VM server, both of which also had the same Ceph filesystem mounted.

And one of the three booted up fine afterwards with no apparent ill effects. Thankfully it's my office machine, the one I spend the most time sitting at, but it's also not in the lab so losing *both* of my lab workstations is going to be a big hit to productivity until I figure out what happened and fix it.

One of them is hanging in DXE doing USB initialization, and the ...

2026-04-19T07:25:55Z

In reply to nevent1q…w63u
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One of them is hanging in DXE doing USB initialization, and the other is able to get into the UEFI configuration menu, the boot device selection menu, but when I select either the internal disk or a removeable Debian live disk it thinks for a few seconds then reboots.

OK so... on my surviving workstation, the crash dump shows it was ...

2026-04-19T07:24:59Z

OK so... on my surviving workstation, the crash dump shows it was a null deref in the Ceph kernel module in ceph_mds_check_access.

Annoying, but this should have been trivially fixed with a reboot. On this machine, it was.

So why are my other two workstations not coming up?