11 ms·

Examining a vintage RAM chip, I find a counterfeit with a different die inside

462 points by darwhy 9y ago

gesman 9y ago
Chip inside of the computer with a little telephone hidden inside. You don't mind if your computer will dial in to China sometime, do you?
- jzebedee 9y ago
  Not the premise. This is an issue of taking a cheap, touch-tone chip and repackaging it as a more expensive product. The chip itself is not dialing out to anywhere since the final product wouldn't even work when installed. Just a counterfeiting scam.
  - bryanlarsen 9y ago
    Comparing the die shot to the 3101 die shot, it appears that the DTMF chip is significantly more expensive to produce than the 64 bit RAM chip. But perhaps they had a large stockpile of DTMF chips they wanted to get rid of.
    - djsumdog 9y ago
      Maybe this was labeled a decade+ ago and the ebayer is just some salvager going through a warehouse. There's no way someone would go through that effort today, with neither chip being that expensive.
      - cat199 9y ago
        probably quite the opposite: e-waste disposal companies inventorying useless ICs for pin count vs barely useful ones and relabeling.. spend .01c to get .05c times 1 bazillion and you might actually make some money
- sweep3r 9y ago
  A little telephone? This just produces DTMF tones...
happycube 9y ago
"The eBay seller gave him a refund. The seller explained that the chip must have been damaged in shipping! (Clearly you should pack your chips carefully so they don't turn into something else entirely.)" ;)
- ComodoHacker 9y ago
  ...or get replaced with bugged modification by CIA!
- rzzzt 9y ago
  Percussive electromigration.
  - comex 9y ago
    Maybe it was packed next to a wand of polymorph.
  - zentiggr 9y ago
    Kudos.... I'm stealing that for HDD use :)
- hammock 9y ago
  Plausible deniability is a powerful concept
- rasz 9y ago
  Im sad there was no info about feedback left by the buyer. Refund usually makes people not leave any (reciprocation) :(
- rothbardrand 9y ago
  The seller probably had few options to choose from (eBay supporting software is often bad) and this was the closest that would be accurate-- namely, I think the wrong thing was shipped- either to the seller or to the buyer.
pavel_lishin 9y ago
> As for Robert Baruch's purchase of the chip, he contacted the eBay seller who gave him a refund. The seller explained that the chip must have been damaged in shipping! I think at that point, you report them to Ebay for fraud, don't you? Or is that just spitting in the ocean?
- djsumdog 9y ago
  It was more likely some salvager cleaning out a warehouse of old crap. Maybe they were printed in the same Fab and a whole batch of these got mislabeled? Maybe someone intentionally relabeled them years ago back when they were worth more?
  - pavel_lishin 9y ago
    I'd argue that if you don't know what you're selling, you're still committing fraud.
    - cat199 9y ago
      So pretty much every grocery/convenince store, pharmacy, or any other retailer that relies on upstream supply chains is fraudulent because they have to rely on externally verified sources of trust and don't "know" what they are selling?
    - rocky1138 9y ago
      Have you ever heard of 'mens rea' [0]? Essentially, I'd agree only if it could be proven that they knew the goods were shady but had a "don't ask, don't tell" policy and only used the ignorance as a shield to give them plausible deniability. [0] https://en.wikipedia.org/wiki/Mens_rea https://en.wikipedia.org/wiki/Mens_rea
  - noonespecial 9y ago
    If that were the case, I'd care very much about a mislabeled/counterfeit good and thank the buyer very much for letting me know, as well as immediately giving that refund. Claiming that it was "damaged in shipping" is the shadiest part of the whole deal. It pretty much guarantees the intentional fraud of the seller.
kumarvvr 9y ago
So, the chip is fake, but how come such chips could work satisfactorily in their place in a PC??
- Rotten194 9y ago
  It wouldn't.
- deleted 9y ago
  [deleted]
- vardump 9y ago
  I don't think 8 byte RAM chip is used in any computer. You'd need 128 of these to get one kilobyte of RAM!
  - kens 9y ago
    Some historical background: The 8 byte RAM chips were used in minicomputers in the 1970s to implement CPU registers, for example in the Xerox Alto. The advantage of TTL was that it was much faster than MOS memory.
- kutkloon7 9y ago
  This is downvoted, but actually a legitimate question. Often, counterfeits do work, but just don't match the specifications with respect to voltage rating, durability, etc.
  - moftz 9y ago
    Yes, a totally non-working fake isn't the most common thing to occur. Unless they got the counterfeits for free, the vendor is losing money on replacing the fakes with real ones. They are assuming everyone will either never use the chip or just assume they fried the chip and buy another. Selling rejects from the fab or clones as legit is much easier to get away with.
- sowbug 9y ago
  Theory: this particular chip is obscure, and the very few who would buy it are either (1) collectors who never intended to use it, or (2) people stockpiling hard-to-find parts for legacy hardware. Either buyer won't discover that the chip is fake until the seller has long-ago skipped town. Indeed, Ken was in group #1 (collector) but a very unusual kind who then proceeded to tear down the chip.
thmsths 9y ago
I would be interested to know how the Pentagon deals with those 15% of counterfeit ICs, the implications are quite scary.
- anfractuosity 9y ago
  Yeah that does sound scary. I'm just looking at the pdf they link to in this article: https://www.semiconductors.org/clientuploads/Anti-Counterfeiting/SIA%20Anti-Counterfeiting%20Whitepaper.pdf https://www.semiconductors.org/clientuploads/Anti-Counterfei... In the summary they say, the following on how to 'win the battle' "The key to winning the battle against counterfeit semiconductors is elegantly simple: Exclusively buy semiconductor products either directly from the Original Component Manufacturer (OCM) or directly from the OCM’s Authorized Distributors/Resellers." I wonder if they have hardware to test the functioning of chips, like testing them to ensure they meet the parameters on the datasheets (like current consumption etc.).
  - TFortunato 9y ago
    There absolutely is test hardware for the functioning of chips. After all, those datasheet numbers have to come from somewhere, right? ;-) Before I got into robotics, I worked in the semiconductor world as a test and product engineer for a couple of IC manufacturers. A lot of my job involved figuring out how to test every parameter we were going to put on the datasheet, writing code to test it quickly, and then doing statistical analysis of the results over thousands upon thousands of devices to make sure they met requirements. It was an interesting experience. We used some very high end test equipment, made by companies like Teradyne, and for each part (or family of parts in some cases), we would make a custom board which would mate to the test equipment on one side, and had sockets for the part we were testing, along with any support circuitry required. I think the problem with doing some sort of acceptance testing is that unless you buy the parts directly from the manufacturer or their distributors, it's very hard to verify that the part meets it's specs, unless you already have this kind of dedicated testing equipment and code, especially when you want to start measuring analog parameters (current consumption, logic levels, etc.), and don't think it would be worth the trouble in most cases. (Military / Space may be a special case, where critical parts may stop being manufactured by the original manufacturer and they do have to do this sort of thing, but as far as I know, it isn't typical).
windlessstorm 9y ago
Thanks for this, was an awesome read. Any more such blogs for learning and getting into electronics and such low level stuffs? PS. I am newbie software engineer (c/networking) and recently fascinated and drawn towards electronics.
- rwmj 9y ago
  Not sure about blogs, but I can recommend the book The Art of Electronics (Horowitz and Hill). It's very expensive, but worth every penny.
  - EnFinlay 9y ago
    It's the bible for undergrand EE students. Highly recommend.
    - tesseract 9y ago
      I love H&H but feel it is worth pointing out it is more of a handbook than an introductory electronics book. In particular it doesn't really aim to teach basic circuit analysis (although it does restate a fair bit, for the benefit of those like myself whose prior instruction covered all the theory but failed to instill good intuition). Unfortunately I don't have a solid recommendation for a true beginner's resource for electronics.
  - cr0sh 9y ago
    I'll second this book, but also recommend Grob's Basic Electronics. Also very expensive... ...but that last bit has a caveat: These books are only expensive if you opt for "the latest edition". If you are doing this at a hobby level (vs taking a dedicated college course or similar), purchasing an older edition will serve you just as well. Electronics haven't changed that much between today and when the book's prior revision was published (or the revision before that - or even 5+ revisions ago). Most of the changes are likely going to be very small and minor errata (spelling mistakes most likely). All that said, Art of Electronics doesn't appear too expensive, even for a current edition (provided you stay away from the academic hardcover version, I'd imagine). Grob's is on a different level price-wise, but again, you can find cheaper versions. I'd also like to point out Forrest M. Mims III's "Engineer's Mini Notebooks" series as something to go along with the above two books as well (or alone, if you just want the quick-n-dirty hack-on-electronics thing). They were originally sold by Radio Shack back in the day, but today can be picked up via Mims' site (which I think just redirects to Amazon). Old "vintage" copies (the new version combine multiple notebooks into one) can also be had fairly cheaply. They don't go into as much depth as the earlier mentioned books, but they can prove to give a quick and good understanding of the basics (provided you consume them in the proper order of course). But if you're serious about electronics, they can't substitute for the previous mentioned volumes; get those first, then get the Mims volumes later (IIRC, Mims did write a separate book on learning electronics - it's probably mentioned on his site).
robryk 9y ago
If one counterfeits a chip using something that will not work at all, why put any chip inside at all? Why not just place a resistor between VCC and GND?
- eternauta3k 9y ago
  I'm guessing they buy surplus chips and change the markings. Cheaper and easier than manufacturing and bonding a resistor die.
- peller 9y ago
  In this case, they were just taking an existing chip and relabeling it to something with the same pin-out/form-factor that they could sell for a higher value.
- DanBC 9y ago
  There's a market for some old, obscure, obsolete ICs. People approach brokers, who search for them. Other people - scam artists - see what's being searched for, and take a different IC in the same package and remove the existing markings, and put new fake markings on. They then sell this as the other IC. By the time the ICs are tested the money has gone. (Which should be a hint - if they're not offering regular invoicing and 30 days payment they might not be trustworthy). tl;dr not enough people design _for production_, and it makes things much harder.
  - moftz 9y ago
    When you just need one to a few of something, no vendor is going to bother with giving you quotes/invoices/etc when they know you a) aren't a big company to keep around for future business and b) aren't buying enough for any of that extra work to be worth it. If I'm working on an SBC and need a couple floppy driver chips, I'm not going to find any "real" vendors that have them in stock. All I'm going to find are second-hand dealers that might be selling fakes.
- joezydeco 9y ago
  Perhaps the DTMF chips were under some kind of patent/royalty and were being smuggled into the country?
jackblack8989 9y ago
Any experts here care to tell how does one check for RAM quality? Does CPU-Z do it? (Writing from work, don't have admin perms to use) Not talking about this particular case, but maybe case of a RAM not working in general.
- Retr0spectrum 9y ago
  Memtest86+ is the gold standard of memory testing for modern systems. Recent versions even test for rowhammer iirc.
- Elv13 9y ago
  `memcheck86` is included in most Linux LiveCDs (ok, let's start to call them live USB sticks?). It will stress-test the system DDR/SDRAM. If you need to check external memory (GPU, IoT, etc) then there is some tools online. Note that memtest86 doesn't test against Rowhammer like attacks probabilities. You can also use some overclocking features in advanced motherboard to push the memory beyond factory settings and see how far it gets before it starts to misbehave.
- tawayway 9y ago
  memtest86 can do functional tests.
- dfox 9y ago
  Generally you use memtest86+ or something similar (IIRC Windows' bootloader contains something like that since vista). On the other hand I've seen memory module with sufficiently unfortunate pattern of broken bits, that it could not be detected by memtest86. Even such tools need some part of memory that they run from and thus does not get tested (also some memory is reserved for BIOS). The problem manifested itself by completely unusable Windows and occassionally flipped bits in files downloaded from network on Linux (I assume that on Linux the faulty bit ended up in DMA bounce buffer, while on windows in something significantly more critical). To confirm my hunch, that it was memory related I netcat'ed few GB worth of CHARGEN output and analyzed the pattern of bit errors, which were perfectly aligned on some boundary. Finding which module was faulty then involved rearranging modules, running memtest86 and repeating the CHARGEN experiment. Edit: actually diagnosing this took about month and half. memtest86 was passing and there was unrelated known hardware bug in used network card which I though might be related to observed behavior. Experiment with chargen was motivated by finding out whether the bit errors were somehow aligned to TCP segment boundaries, instead I found out they were aligned on some quite large power of two, which clearly pointed to memory issue.
kutkloon7 9y ago
Ken Shirriff is amazing. His blog entries are really worth reading.
jxramos 9y ago
Very cool article. I found myself strangely hit with a wave of nostalgia when the piece came upon "DTMF: dialing a Touch-Tone phone"
- hammock 9y ago
  Anarchist cookbook, blue box, buzz box, etc...
  - a1k0n 9y ago
    Don't forget the red box, which you could make by replacing the 3.579545 MHz crystal powering the chip that the OP reverse engineered with a 6.5536MHz one, and then the top row and bottom column tones become 1700 / 2200Hz to simulate the pay phone nickel / dime / quarter tones.
NikolaNovak 9y ago
Hah... Through the first few sentences I kept wondering which wondrous architecture are we talking about, that "64-bit" memory chip is considered "vintage"...? It took me embarrassingly long to realize that it's not 64-bit bus, it's a 64-bit chip... holding an amazing 4x16bits=64bits of data total. Just goes to show it's hard to be sure where your unspoken assumptions may lie.... :-)
- pwg 9y ago
  What one thought also depends quite heavily upon whether one was involved in the field in some way during the 74xx series heyday. For those of us that were, seeing "64-bit" and "TTL" together immediately told us it was a chip that stored 64 bits worth of data.
  - NikolaNovak 9y ago
    I thought as much :)
  - jfoutz 9y ago
    One of the classes late in my undergrad program was computer engineering for comp-sci. Took us through basic combinatoric circuits, mux/demux, 7 segment display decoding, all that classic ttl stuff. final project was a 4 bit computer with 64 bits of ram. I remember spending many hours in the lab debugging my wiring. But it was super cool to toggle in data, advance the pc, toggle in an op, advance the pc and toggle in more data. i think i demonstrated 4 + 5 - 7 * 2 fun class.
- gumby 9y ago
  > Just goes to show it's hard to be sure where your unspoken assumptions may lie.... :-) Three years ago I posted a link on HN about TTL (Lransister-Lransister Logic) being 50 years old, entitled "50 years of TTL". Similarly, many people unsurprisingly expected it to be a story about a weird Time To Live field.
  - taneq 9y ago
    Just goes to show how hugely context-dependent that desperately-overloaded TLA namespace is, and how important it is to actually define your acronyms the first time you use them, no matter how obvious you think it is that TLA means three-letter acronym...
todd8 9y ago
This, along with the complaints in the comments here, is quite discouraging. I'm ready to give up on third-party sellers on Amazon, see https://news.ycombinator.com/item?id=14993216 https://news.ycombinator.com/item?id=14993216 [I Fell Victim to a $1,500 Used Camera Lens Scam on Amazon], and now Ebay looks like it's not going to be a viable alternative.
- cuckcuckspruce 9y ago
  eBay has always been a crap-shoot in this regard, even before the P-p-p-powerbook days[1]. [1] Potentially NSFW: https://forums.somethingawful.com/showthread.php?threadid=1016390 https://forums.somethingawful.com/showthread.php?threadid=10..., SFW summary: https://www.engadget.com/2004/05/14/scamming-the-scammer/ https://www.engadget.com/2004/05/14/scamming-the-scammer/
jk2323 9y ago
"Why would someone go to the effort of creating counterfeit memory chips that couldn't possibly work? The 74LS189 is a fairly obscure part, so I wouldn't have expected counterfeiting it to be worth the effort. The chips sell for about a dollar on eBay, so there's not a huge profit opportunity. " This sounds obscure. Small/Tiny mark up. Small market. High fake detection rate. I wonder if there is something about the story that we miss.
- metalliqaz 9y ago
  Probably more likely that someone found themselves with a bunch of warehoused touch tone dialer chips (essentially worthless now), and decided to label them as something else -- anything else -- to be able to salvage at least a few bucks out of it. Either that or a plain old mistake. The new guy loaded the wrong data into the printer.
  - SmellyGeekBoy 9y ago
    > Either that or a plain old mistake. The new guy loaded the wrong data into the printer. I'd also like to think that Hanlon's Razor applies here. Chips were mislabeled, wasn't worth the time / effort / ink to relabel something that costs pennies to manufacture so they're earmarked for the incinerator but somehow end up back in the supply chain. Stuff like this happens.
- lb1lf 9y ago
  My guess: someone found a lot of these chips, realized there was hardly a market for them and had them relabeled as just about anything available in the same package to generate sales. Also, pushing fakes in small quantities may not be such a bad idea; after all - rip someone off for $1 and chances are he'll curse you and let it go; rip someone off for $1M and chances are he'll curse you and get law enforcement involved.
- mywittyname 9y ago
  > High fake detection rate. Maybe not in time. The companies buy lots of stuff that never gets used. It seems totally plausible for them to use up their end-of-year-budget stocking up on parts they don't necessarily need or expect to use through non-conventional channels. Plus, unless you dig into it like this guy did, he can just say what he did and give a refund.
yuhong 9y ago
This reminds me of the 1988 DRAM shortage.
CamperBob2 9y ago
The motivation (for the use of an LFSR instead of a traditional counter) is a shift register takes up less space than a counter on the chip; if you don't need the counter to count in the normal order, this is a good tradeoff That's kind of a profound observation, even though it's obvious once you think about it. It never occurred to me that a maximal-length shift register is actually a simpler, more efficient logic structure than either a carry-chain adder or a ring counter.
- kens 9y ago
  One of the old TI microcontrollers saved a few transistors in the program counter by using a shift register this way instead of an actual counter. As a result, instructions in your program don't execute sequentially, but in a pseudo-random order. This isn't a problem, though, since you just put the code in the ROM in the same pseudo-random order and everything works out. The underlying thing that makes the shift register more efficient is that you can build a dynamic shift register stage with two inverters and two pass transistor pairs, while the flip flop for a counter stage is probably six gates.
basicplus2 9y ago
Now I know why that project I designed didn't work...
agjacobson 9y ago
Why do you think the 74LS189 was being counterfeited? It was the touch tone chip being counterfeited, and disguised as a 74LS189. The buyer knew the ruse.
brooklyntribe 9y ago
From his posts, he's like the smartest person in the world. At least that's my impression. Mine bitcoin with paper and pencil? Is anyone else in the world even thinking about something so far out?
kazinator 9y ago
> Why would someone go to the effort of creating counterfeit memory chips that couldn't possibly work? Because it's maybe a mistake? Some of the people people working at the factory don't know a potato chip from a silicon chip? True counterfeit chips use the correct die. It is stolen, but the knock-offs cut corners: you're getting something that is not quality controlled, or perhaps even a reject off the factory floor (that might just work in your use case so you won't notice). Sometimes counterfeit chips use a different implementation, but of the right general spec. Well sort of: https://news.ycombinator.com/item?id=14685671 https://news.ycombinator.com/item?id=14685671 ("Ti NE555 – real vs fake: weekend die-shot ").
jeffwass 9y ago
One of the first pics in that article comes from an earlier chip he previously reviewed - the Intel 3101. I'm proud to say my dad provided Ken with those two Intel 3101 chips. Ken's review of the 3101 is here: http://www.righto.com/2017/07/inside-intels-first-product-3101-ram.html?m=1 http://www.righto.com/2017/07/inside-intels-first-product-31... This is the first IC ever produced by Intel. My dad had a few of these chips from an old computer. Some of the 3101 chips are from such early runs they don't even have the usual date stamps on the packages, and were outsourced by Intel into generic wirebonded IC packages.

462 points by darwhy 9y ago

Chip inside of the computer with a little telephone hidden inside. You don't mind if your computer will dial in to China sometime, do you?

jzebedee 9y ago
Not the premise. This is an issue of taking a cheap, touch-tone chip and repackaging it as a more expensive product. The chip itself is not dialing out to anywhere since the final product wouldn't even work when installed. Just a counterfeiting scam.
- bryanlarsen 9y ago
  Comparing the die shot to the 3101 die shot, it appears that the DTMF chip is significantly more expensive to produce than the 64 bit RAM chip. But perhaps they had a large stockpile of DTMF chips they wanted to get rid of.
  - djsumdog 9y ago
    Maybe this was labeled a decade+ ago and the ebayer is just some salvager going through a warehouse. There's no way someone would go through that effort today, with neither chip being that expensive.
    - cat199 9y ago
      probably quite the opposite: e-waste disposal companies inventorying useless ICs for pin count vs barely useful ones and relabeling.. spend .01c to get .05c times 1 bazillion and you might actually make some money
sweep3r 9y ago
A little telephone? This just produces DTMF tones...

happycube 9y ago

"The eBay seller gave him a refund. The seller explained that the chip must have been damaged in shipping! (Clearly you should pack your chips carefully so they don't turn into something else entirely.)" ;)

ComodoHacker 9y ago
...or get replaced with bugged modification by CIA!
rzzzt 9y ago
Percussive electromigration.
- comex 9y ago
  Maybe it was packed next to a wand of polymorph.
- zentiggr 9y ago
  Kudos.... I'm stealing that for HDD use :)
hammock 9y ago
Plausible deniability is a powerful concept
rasz 9y ago
Im sad there was no info about feedback left by the buyer. Refund usually makes people not leave any (reciprocation) :(
rothbardrand 9y ago
The seller probably had few options to choose from (eBay supporting software is often bad) and this was the closest that would be accurate-- namely, I think the wrong thing was shipped- either to the seller or to the buyer.

pavel_lishin 9y ago

> As for Robert Baruch's purchase of the chip, he contacted the eBay seller who gave him a refund. The seller explained that the chip must have been damaged in shipping! I think at that point, you report them to Ebay for fraud, don't you? Or is that just spitting in the ocean?

djsumdog 9y ago
It was more likely some salvager cleaning out a warehouse of old crap. Maybe they were printed in the same Fab and a whole batch of these got mislabeled? Maybe someone intentionally relabeled them years ago back when they were worth more?
- pavel_lishin 9y ago
  I'd argue that if you don't know what you're selling, you're still committing fraud.
  - cat199 9y ago
    So pretty much every grocery/convenince store, pharmacy, or any other retailer that relies on upstream supply chains is fraudulent because they have to rely on externally verified sources of trust and don't "know" what they are selling?
  - rocky1138 9y ago
    Have you ever heard of 'mens rea' [0]? Essentially, I'd agree only if it could be proven that they knew the goods were shady but had a "don't ask, don't tell" policy and only used the ignorance as a shield to give them plausible deniability. [0] https://en.wikipedia.org/wiki/Mens_rea https://en.wikipedia.org/wiki/Mens_rea
- noonespecial 9y ago
  If that were the case, I'd care very much about a mislabeled/counterfeit good and thank the buyer very much for letting me know, as well as immediately giving that refund. Claiming that it was "damaged in shipping" is the shadiest part of the whole deal. It pretty much guarantees the intentional fraud of the seller.

kumarvvr 9y ago

So, the chip is fake, but how come such chips could work satisfactorily in their place in a PC??

Rotten194 9y ago
It wouldn't.
deleted 9y ago
[deleted]
vardump 9y ago
I don't think 8 byte RAM chip is used in any computer. You'd need 128 of these to get one kilobyte of RAM!
- kens 9y ago
  Some historical background: The 8 byte RAM chips were used in minicomputers in the 1970s to implement CPU registers, for example in the Xerox Alto. The advantage of TTL was that it was much faster than MOS memory.
kutkloon7 9y ago
This is downvoted, but actually a legitimate question. Often, counterfeits do work, but just don't match the specifications with respect to voltage rating, durability, etc.
- moftz 9y ago
  Yes, a totally non-working fake isn't the most common thing to occur. Unless they got the counterfeits for free, the vendor is losing money on replacing the fakes with real ones. They are assuming everyone will either never use the chip or just assume they fried the chip and buy another. Selling rejects from the fab or clones as legit is much easier to get away with.
sowbug 9y ago
Theory: this particular chip is obscure, and the very few who would buy it are either (1) collectors who never intended to use it, or (2) people stockpiling hard-to-find parts for legacy hardware. Either buyer won't discover that the chip is fake until the seller has long-ago skipped town. Indeed, Ken was in group #1 (collector) but a very unusual kind who then proceeded to tear down the chip.

thmsths 9y ago

I would be interested to know how the Pentagon deals with those 15% of counterfeit ICs, the implications are quite scary.

anfractuosity 9y ago
Yeah that does sound scary. I'm just looking at the pdf they link to in this article: https://www.semiconductors.org/clientuploads/Anti-Counterfeiting/SIA%20Anti-Counterfeiting%20Whitepaper.pdf https://www.semiconductors.org/clientuploads/Anti-Counterfei... In the summary they say, the following on how to 'win the battle' "The key to winning the battle against counterfeit semiconductors is elegantly simple: Exclusively buy semiconductor products either directly from the Original Component Manufacturer (OCM) or directly from the OCM’s Authorized Distributors/Resellers." I wonder if they have hardware to test the functioning of chips, like testing them to ensure they meet the parameters on the datasheets (like current consumption etc.).
- TFortunato 9y ago
  There absolutely is test hardware for the functioning of chips. After all, those datasheet numbers have to come from somewhere, right? ;-) Before I got into robotics, I worked in the semiconductor world as a test and product engineer for a couple of IC manufacturers. A lot of my job involved figuring out how to test every parameter we were going to put on the datasheet, writing code to test it quickly, and then doing statistical analysis of the results over thousands upon thousands of devices to make sure they met requirements. It was an interesting experience. We used some very high end test equipment, made by companies like Teradyne, and for each part (or family of parts in some cases), we would make a custom board which would mate to the test equipment on one side, and had sockets for the part we were testing, along with any support circuitry required. I think the problem with doing some sort of acceptance testing is that unless you buy the parts directly from the manufacturer or their distributors, it's very hard to verify that the part meets it's specs, unless you already have this kind of dedicated testing equipment and code, especially when you want to start measuring analog parameters (current consumption, logic levels, etc.), and don't think it would be worth the trouble in most cases. (Military / Space may be a special case, where critical parts may stop being manufactured by the original manufacturer and they do have to do this sort of thing, but as far as I know, it isn't typical).

windlessstorm 9y ago

Thanks for this, was an awesome read. Any more such blogs for learning and getting into electronics and such low level stuffs? PS. I am newbie software engineer (c/networking) and recently fascinated and drawn towards electronics.

rwmj 9y ago
Not sure about blogs, but I can recommend the book The Art of Electronics (Horowitz and Hill). It's very expensive, but worth every penny.
- EnFinlay 9y ago
  It's the bible for undergrand EE students. Highly recommend.
  - tesseract 9y ago
    I love H&H but feel it is worth pointing out it is more of a handbook than an introductory electronics book. In particular it doesn't really aim to teach basic circuit analysis (although it does restate a fair bit, for the benefit of those like myself whose prior instruction covered all the theory but failed to instill good intuition). Unfortunately I don't have a solid recommendation for a true beginner's resource for electronics.
- cr0sh 9y ago
  I'll second this book, but also recommend Grob's Basic Electronics. Also very expensive... ...but that last bit has a caveat: These books are only expensive if you opt for "the latest edition". If you are doing this at a hobby level (vs taking a dedicated college course or similar), purchasing an older edition will serve you just as well. Electronics haven't changed that much between today and when the book's prior revision was published (or the revision before that - or even 5+ revisions ago). Most of the changes are likely going to be very small and minor errata (spelling mistakes most likely). All that said, Art of Electronics doesn't appear too expensive, even for a current edition (provided you stay away from the academic hardcover version, I'd imagine). Grob's is on a different level price-wise, but again, you can find cheaper versions. I'd also like to point out Forrest M. Mims III's "Engineer's Mini Notebooks" series as something to go along with the above two books as well (or alone, if you just want the quick-n-dirty hack-on-electronics thing). They were originally sold by Radio Shack back in the day, but today can be picked up via Mims' site (which I think just redirects to Amazon). Old "vintage" copies (the new version combine multiple notebooks into one) can also be had fairly cheaply. They don't go into as much depth as the earlier mentioned books, but they can prove to give a quick and good understanding of the basics (provided you consume them in the proper order of course). But if you're serious about electronics, they can't substitute for the previous mentioned volumes; get those first, then get the Mims volumes later (IIRC, Mims did write a separate book on learning electronics - it's probably mentioned on his site).

robryk 9y ago

If one counterfeits a chip using something that will not work at all, why put any chip inside at all? Why not just place a resistor between VCC and GND?

eternauta3k 9y ago
I'm guessing they buy surplus chips and change the markings. Cheaper and easier than manufacturing and bonding a resistor die.
peller 9y ago
In this case, they were just taking an existing chip and relabeling it to something with the same pin-out/form-factor that they could sell for a higher value.
DanBC 9y ago
There's a market for some old, obscure, obsolete ICs. People approach brokers, who search for them. Other people - scam artists - see what's being searched for, and take a different IC in the same package and remove the existing markings, and put new fake markings on. They then sell this as the other IC. By the time the ICs are tested the money has gone. (Which should be a hint - if they're not offering regular invoicing and 30 days payment they might not be trustworthy). tl;dr not enough people design _for production_, and it makes things much harder.
- moftz 9y ago
  When you just need one to a few of something, no vendor is going to bother with giving you quotes/invoices/etc when they know you a) aren't a big company to keep around for future business and b) aren't buying enough for any of that extra work to be worth it. If I'm working on an SBC and need a couple floppy driver chips, I'm not going to find any "real" vendors that have them in stock. All I'm going to find are second-hand dealers that might be selling fakes.
joezydeco 9y ago
Perhaps the DTMF chips were under some kind of patent/royalty and were being smuggled into the country?

jackblack8989 9y ago

Any experts here care to tell how does one check for RAM quality? Does CPU-Z do it? (Writing from work, don't have admin perms to use) Not talking about this particular case, but maybe case of a RAM not working in general.

Retr0spectrum 9y ago
Memtest86+ is the gold standard of memory testing for modern systems. Recent versions even test for rowhammer iirc.
Elv13 9y ago
`memcheck86` is included in most Linux LiveCDs (ok, let's start to call them live USB sticks?). It will stress-test the system DDR/SDRAM. If you need to check external memory (GPU, IoT, etc) then there is some tools online. Note that memtest86 doesn't test against Rowhammer like attacks probabilities. You can also use some overclocking features in advanced motherboard to push the memory beyond factory settings and see how far it gets before it starts to misbehave.
tawayway 9y ago
memtest86 can do functional tests.
dfox 9y ago
Generally you use memtest86+ or something similar (IIRC Windows' bootloader contains something like that since vista). On the other hand I've seen memory module with sufficiently unfortunate pattern of broken bits, that it could not be detected by memtest86. Even such tools need some part of memory that they run from and thus does not get tested (also some memory is reserved for BIOS). The problem manifested itself by completely unusable Windows and occassionally flipped bits in files downloaded from network on Linux (I assume that on Linux the faulty bit ended up in DMA bounce buffer, while on windows in something significantly more critical). To confirm my hunch, that it was memory related I netcat'ed few GB worth of CHARGEN output and analyzed the pattern of bit errors, which were perfectly aligned on some boundary. Finding which module was faulty then involved rearranging modules, running memtest86 and repeating the CHARGEN experiment. Edit: actually diagnosing this took about month and half. memtest86 was passing and there was unrelated known hardware bug in used network card which I though might be related to observed behavior. Experiment with chargen was motivated by finding out whether the bit errors were somehow aligned to TCP segment boundaries, instead I found out they were aligned on some quite large power of two, which clearly pointed to memory issue.

kutkloon7 9y ago

Ken Shirriff is amazing. His blog entries are really worth reading.

jxramos 9y ago

Very cool article. I found myself strangely hit with a wave of nostalgia when the piece came upon "DTMF: dialing a Touch-Tone phone"

hammock 9y ago
Anarchist cookbook, blue box, buzz box, etc...
- a1k0n 9y ago
  Don't forget the red box, which you could make by replacing the 3.579545 MHz crystal powering the chip that the OP reverse engineered with a 6.5536MHz one, and then the top row and bottom column tones become 1700 / 2200Hz to simulate the pay phone nickel / dime / quarter tones.

NikolaNovak 9y ago

Hah... Through the first few sentences I kept wondering which wondrous architecture are we talking about, that "64-bit" memory chip is considered "vintage"...? It took me embarrassingly long to realize that it's not 64-bit bus, it's a 64-bit chip... holding an amazing 4x16bits=64bits of data total. Just goes to show it's hard to be sure where your unspoken assumptions may lie.... :-)

pwg 9y ago
What one thought also depends quite heavily upon whether one was involved in the field in some way during the 74xx series heyday. For those of us that were, seeing "64-bit" and "TTL" together immediately told us it was a chip that stored 64 bits worth of data.
- NikolaNovak 9y ago
  I thought as much :)
- jfoutz 9y ago
  One of the classes late in my undergrad program was computer engineering for comp-sci. Took us through basic combinatoric circuits, mux/demux, 7 segment display decoding, all that classic ttl stuff. final project was a 4 bit computer with 64 bits of ram. I remember spending many hours in the lab debugging my wiring. But it was super cool to toggle in data, advance the pc, toggle in an op, advance the pc and toggle in more data. i think i demonstrated 4 + 5 - 7 * 2 fun class.
gumby 9y ago
> Just goes to show it's hard to be sure where your unspoken assumptions may lie.... :-) Three years ago I posted a link on HN about TTL (Lransister-Lransister Logic) being 50 years old, entitled "50 years of TTL". Similarly, many people unsurprisingly expected it to be a story about a weird Time To Live field.
- taneq 9y ago
  Just goes to show how hugely context-dependent that desperately-overloaded TLA namespace is, and how important it is to actually define your acronyms the first time you use them, no matter how obvious you think it is that TLA means three-letter acronym...

todd8 9y ago

This, along with the complaints in the comments here, is quite discouraging. I'm ready to give up on third-party sellers on Amazon, see https://news.ycombinator.com/item?id=14993216 https://news.ycombinator.com/item?id=14993216 [I Fell Victim to a $1,500 Used Camera Lens Scam on Amazon], and now Ebay looks like it's not going to be a viable alternative.

cuckcuckspruce 9y ago
eBay has always been a crap-shoot in this regard, even before the P-p-p-powerbook days[1]. [1] Potentially NSFW: https://forums.somethingawful.com/showthread.php?threadid=1016390 https://forums.somethingawful.com/showthread.php?threadid=10..., SFW summary: https://www.engadget.com/2004/05/14/scamming-the-scammer/ https://www.engadget.com/2004/05/14/scamming-the-scammer/

jk2323 9y ago

"Why would someone go to the effort of creating counterfeit memory chips that couldn't possibly work? The 74LS189 is a fairly obscure part, so I wouldn't have expected counterfeiting it to be worth the effort. The chips sell for about a dollar on eBay, so there's not a huge profit opportunity. " This sounds obscure. Small/Tiny mark up. Small market. High fake detection rate. I wonder if there is something about the story that we miss.

metalliqaz 9y ago
Probably more likely that someone found themselves with a bunch of warehoused touch tone dialer chips (essentially worthless now), and decided to label them as something else -- anything else -- to be able to salvage at least a few bucks out of it. Either that or a plain old mistake. The new guy loaded the wrong data into the printer.
- SmellyGeekBoy 9y ago
  > Either that or a plain old mistake. The new guy loaded the wrong data into the printer. I'd also like to think that Hanlon's Razor applies here. Chips were mislabeled, wasn't worth the time / effort / ink to relabel something that costs pennies to manufacture so they're earmarked for the incinerator but somehow end up back in the supply chain. Stuff like this happens.
lb1lf 9y ago
My guess: someone found a lot of these chips, realized there was hardly a market for them and had them relabeled as just about anything available in the same package to generate sales. Also, pushing fakes in small quantities may not be such a bad idea; after all - rip someone off for $1 and chances are he'll curse you and let it go; rip someone off for $1M and chances are he'll curse you and get law enforcement involved.
mywittyname 9y ago
> High fake detection rate. Maybe not in time. The companies buy lots of stuff that never gets used. It seems totally plausible for them to use up their end-of-year-budget stocking up on parts they don't necessarily need or expect to use through non-conventional channels. Plus, unless you dig into it like this guy did, he can just say what he did and give a refund.

yuhong 9y ago

This reminds me of the 1988 DRAM shortage.

CamperBob2 9y ago

The motivation (for the use of an LFSR instead of a traditional counter) is a shift register takes up less space than a counter on the chip; if you don't need the counter to count in the normal order, this is a good tradeoff That's kind of a profound observation, even though it's obvious once you think about it. It never occurred to me that a maximal-length shift register is actually a simpler, more efficient logic structure than either a carry-chain adder or a ring counter.

kens 9y ago
One of the old TI microcontrollers saved a few transistors in the program counter by using a shift register this way instead of an actual counter. As a result, instructions in your program don't execute sequentially, but in a pseudo-random order. This isn't a problem, though, since you just put the code in the ROM in the same pseudo-random order and everything works out. The underlying thing that makes the shift register more efficient is that you can build a dynamic shift register stage with two inverters and two pass transistor pairs, while the flip flop for a counter stage is probably six gates.

basicplus2 9y ago

Now I know why that project I designed didn't work...

agjacobson 9y ago

Why do you think the 74LS189 was being counterfeited? It was the touch tone chip being counterfeited, and disguised as a 74LS189. The buyer knew the ruse.

brooklyntribe 9y ago

From his posts, he's like the smartest person in the world. At least that's my impression. Mine bitcoin with paper and pencil? Is anyone else in the world even thinking about something so far out?

kazinator 9y ago

> Why would someone go to the effort of creating counterfeit memory chips that couldn't possibly work? Because it's maybe a mistake? Some of the people people working at the factory don't know a potato chip from a silicon chip? True counterfeit chips use the correct die. It is stolen, but the knock-offs cut corners: you're getting something that is not quality controlled, or perhaps even a reject off the factory floor (that might just work in your use case so you won't notice). Sometimes counterfeit chips use a different implementation, but of the right general spec. Well sort of: https://news.ycombinator.com/item?id=14685671 https://news.ycombinator.com/item?id=14685671 ("Ti NE555 – real vs fake: weekend die-shot ").

jeffwass 9y ago

One of the first pics in that article comes from an earlier chip he previously reviewed - the Intel 3101. I'm proud to say my dad provided Ken with those two Intel 3101 chips. Ken's review of the 3101 is here: http://www.righto.com/2017/07/inside-intels-first-product-3101-ram.html?m=1 http://www.righto.com/2017/07/inside-intels-first-product-31... This is the first IC ever produced by Intel. My dad had a few of these chips from an old computer. Some of the 3101 chips are from such early runs they don't even have the usual date stamps on the packages, and were outsourced by Intel into generic wirebonded IC packages.