
Examining a vintage RAM chip, I find a counterfeit with a different die inside - darwhy
http://www.righto.com/2017/08/inside-fake-ram-chip-i-found-something.html
======
NikolaNovak
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
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.

~~~
jfoutz
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.

------
pavel_lishin
> _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?

~~~
DrPhish
Not only is it useless, it can be actively harmful. My wife had her account
"suspended" for reporting too many fraudulent cases when she went on a buying
spree from Chinese sellers. Normally you lose about a 3rd of the things you
buy from China due to: -Non-shipping of items -Loss of items in transit
-Counterfeit items -Damaged items -Completely wrong items -Wrong quantity
items

Turns out she opened too many cases and they "suspended" her account, which is
an eBay euphemism for being banned for life. That means that her account that
she'd been using since 2000 was dead and gone forever, and she was no longer
welcome on the site.

I agree with other posters. The eBay of old is effectively dead. You are
better off buying things from Amazon or Ali Express 99% of the time. The days
of great deals on items are pretty much gone. You can still find some rare and
unusual stuff that is worth buying, but the dominance of eBay now means that
most things are very close to market rate unless (or even if!) they are
counterfeit or some other scam. More like a dollar store than an online
auction house.

~~~
monksy
Much of the time things from Amazon are actually from Aliexpress.

~~~
tluyben2
That is why for a lot of things I prefer Aliexpress: no issues with refunds.
The sellers usually even do not care about proof but just refund.

~~~
hvidgaard
I've bought quite a bit from AliExpress, and the sellers have always send a
new item or refunded. It can be annoying to keep track of, but that's what you
get for the extremely cheap prices.

------
todd8
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
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=10...](https://forums.somethingawful.com/showthread.php?threadid=1016390),
SFW summary: [https://www.engadget.com/2004/05/14/scamming-the-
scammer/](https://www.engadget.com/2004/05/14/scamming-the-scammer/)

------
happycube
"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.)" ;)

~~~
rzzzt
Percussive electromigration.

~~~
comex
Maybe it was packed next to a wand of polymorph.

------
jk2323
"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.

~~~
mywittyname
> 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.

~~~
stordoff
> The companies buy lots of stuff that never gets used

I seem to recall a few years ago, when looking for arcade ICs (Defender RAM
IIRC) that unscrupulous sellers would put working ICs at either end of the
tube, and fakes/faulty parts in the middle. Unless you were using them all to
do a full RAM replacement, you wouldn't know your spares were faulty.

~~~
cable2600
I worked in a PC shop in 1990 and we got RAM chips in bulk and in plastic
tubes. The dealers would put in counterfet chips that would not work because
of shortages. Then issue a refund later on. Some PC shops also ripped off
other PC shops doing horse trading involving RAM or CPU chips. Had a high
defective rate back then. Nobody thpught to examine the chips, either threw
them away, horsetraded them, or sent them back to dealer for a refund.

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

~~~
anfractuosity
Yeah that does sound scary.

I'm just looking at the pdf they link to in this article:
[https://www.semiconductors.org/clientuploads/Anti-
Counterfei...](https://www.semiconductors.org/clientuploads/Anti-
Counterfeiting/SIA%20Anti-Counterfeiting%20Whitepaper.pdf)

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.).

~~~
todd8
This is a bit off topic, but right out of grad-school, around forty years ago,
I worked at Texas Instruments. The process control engineers would do their
best, but to some degree (at least back then), the yield for integrated
circuits coming off the fabrication lines was very tricky to control. So parts
would be tested and sorted by their performance as they came out. The
components that could operate at hight frequency would end up as the more
expensive part numbers. One front end line would end up making a mix of two
part numbers determined by the testing.

Through some kind of magic, the process would be tweaked by the engineers over
time and the yields for the more expensive parts would often increase to the
point where they wouldn't even end up with enough of the low cost parts so
they would just stamp the low cost numbers on the chips that could actually
run under much more demanding conditions.

~~~
anfractuosity
Neat! Don't companies like Intel etc. still 'bin' chips into different
products? Although I'm not sure if the reasons for binning now are different?

~~~
TFortunato
Yep, absolutely still done, and for the same reason (in my experience),
especially with Intel, and other companies who develop their own processes.

What typically happens is that engineers do the best they can before release
to model the process and experiment with building devices at different process
"corners". This gives an idea of what the distribution of different electrical
parameters will look like over the range of expected process variation (logic
levels of FETs, sheet resistances, etc. etc.).

Obviously this data is imperfect, because there are a TON of steps in a modern
semiconductor process, and a TON of variables in each one. (For example, I
worked on Ion Implanters, and we recorded hundreds of variables for our
customers during the run, from vacuum levels, to gas dosages to voltages and
currents in the various accelerator stages).

As parent said, there is another group, who IMO are probably the original "big
data" folks, usually called manufacturing or process engineers. They monitor
the yields, binning and specific electrical measurements of all the wafers and
parts coming off the line, along with process data for all the nanufacturing
steps the wafer has gone through. These guys do the black magic of figuring
out what needs to be tweaked in the process. At the higher levels it involves
a mix of knowledge -- not only statistics and optimization, but also the
semiconductor physics of how these parts actually operate, (since experiments
can get expensive, you want to justify the knobs you are going to tweak!)

------
robryk
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?

~~~
DanBC
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
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.

------
windlessstorm
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
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.

~~~
cr0sh
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).

~~~
tesseract
The previous-edition "hack" you describe applies to many textbooks but
Horowitz and Hill is a bit of a special case. The current edition is the 3rd,
published in 2015. The 2nd edition is from 1989, and while a lot of the
material is timeless (part of why the book has become a classic), as you can
imagine, a lot has changed in the world of electronics since 1989 and
therefore the update to the 3rd edition was widely anticipated for many years.
By all means pick up a 2nd edition if you find one cheap, but it is a book
where it's probably worthwhile to prefer the current edition if you have the
means.

------
brooklyntribe
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?

------
jeffwass
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-31...](http://www.righto.com/2017/07/inside-intels-first-
product-3101-ram.html?m=1)

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.

------
CamperBob2
_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
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.

------
jxramos
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
Anarchist cookbook, blue box, buzz box, etc...

~~~
a1k0n
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.

------
kazinator
> _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 ").

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

~~~
kutkloon7
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
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.

------
kutkloon7
Ken Shirriff is amazing. His blog entries are really worth reading.

------
agjacobson
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.

------
yuhong
This reminds me of the 1988 DRAM shortage.

------
jackblack8989
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.

~~~
dfox
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.

~~~
aesh2Xa1
What do you mean by "CHARGEN?"

~~~
dfox
Standard service on TCP port 19 :) It spits out printable ASCII characters to
anyone who asks as fast as it can.

General wisdom is that it is security hazard and not useful for anything on
the open internet, but having some server with so called "simple TCP/IP
services" in your internal testing LAN is useful for exactly this kind of
debugging.

Edit: this whole debugging happened around january 2009, so at the time when
chargen was long dead and certainly not a service offered by almost anyone on
the internet.

~~~
toast0
Sadly, chargen is still alive on the open internet. It's not really a security
hazard, but it does have a huge DDoS amplification factor, so it's not a good
idea to run it on public IPs (and if you firewall it, do the world a favor and
firewall the incoming requests, don't try to 'fix' it by firewalling the
outgoing responses)

------
basicplus2
Now I know why that project I designed didn't work...

------
gesman
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
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
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
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
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

